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Young, William G. "Tooth wear /." [St. Lucia, Qld.], 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17715.pdf.
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Robb, Nigel Douglas. "Epidemiological studies in tooth wear." Thesis, King's College London (University of London), 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308314.
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Al-Omiri, M. K. "Tooth wear impact on daily living." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269042.
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McLennan, Laura. "Tooth wear, microwear and diet in elasmobranchs." Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/42779.
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As abundant and widespread apex predators, elasmobranchs play influential roles in the food-web dynamics of marine communities. This has obvious implications for fisheries management and marine conservation. For successful conservation, the ecology of a species must be known. An understanding of extinct species ecology is also useful. Unfortunately, diet a key component of a species’ ecology, is relatively understudied in elasmobranchs. For a majority of elasmobranch species, little or no quantitative dietary data exists. This reflects the limitations of current dietary defining methods. This thesis presents two alternative methods that can be used to determine the diet of extinct and extant elasmobranchs: meso-style wear analysis and 3D tooth microtextural analysis. These wear techniques can be applied to small sample sizes, and sampled animals with no stomach contents, thus reducing the impact of study on wild elasmobranch populations. The techniques can also be applied to dried and fossil samples, further reducing the impact of study on wild populations and providing a means for the study of extinct species. Furthermore, these wear techniques provide additional advantages over the traditional methods of stomach contents analysis and observation. The wear, measured through the methods outlined in this thesis, accumulates over a longer timescale. The “snapshot bias” associated with traditional methods is thus overcome when analysing diet via meso-style analyses or 3D microtextural analyses. This thesis also investigates the impact of sediment abrasion to 3D tooth microtextures. Results show that care needs to be taken when comparing fossil specimens originating from deposits with differing sediment compositions. These findings are applicable to any study using 3D microtextural techniques on fossil specimens of any species, as all have been exposed to sediment abrasion before fossilisation. This is the first time that these alternative wear methods have been applied to elasmobranchs. They have displayed the potential to be a powerful tool for the dietary analysis of living and extinct elasmobranchs in the future.
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Olley, Ryan. "Association of dentine hypersensitivity to tooth wear." Thesis, King's College London (University of London), 2012. https://kclpure.kcl.ac.uk/portal/en/theses/association-of-dentine-hypersensitivity-to-tooth-wear(09a7f9b3-e0a7-4f4c-8a2e-b926a89cffc2).html.
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Dentine hypersensitivity (DH) affects up to 57% of patients following exposure of unoccluded dentine tubules. However the aetiology is incompletely understood. These studies investigated the association of DH to tooth wear. A prevalence study investigated risk factors associated with tooth wear and DH on all tooth surfaces in 350 subjects aged 18-35 in SE England. Sextant cumulative scores for DH and tooth wear were validated and positive correlations existed between both (p < 0.0001). Two randomised, single blind in situ studies investigated the degree of dentine tubule occlusion provided by desensitising dentifrices following four days of twice daily brushing with agitated acid challenges on days three and four. In the first in situ study involving 28 healthy subjects, samples were imaged daily using Scanning Electron Microscopy (SEM) and graded using a ‘standard’ visual ordinal scale. On days one and two, an 8% strontium acetate and 8% arginine based desensitising dentifrice demonstrated more occlusion than control paste (p < 0.0001) and water (p < 0.0001, p = 0.0003). On day four, strontium demonstrated more occlusion than all other treatments (p < 0.0001). In a second in situ study involving 30 subjects, an innovative computerised and imaging method was created and validated to quantify tubule occlusion. Samples were imaged with Tandem Scanning Microscopy (TSM) and then SEM. Intra-class correlation of the number of un-occluded tubules counted visually and then by the computational analysis on 10% (n = 47) randomised SEM or TSM images was > 0.8. Positive Spearman correlations existed between the visual ordinal ‘standard’ and the SEM (r = 0.58) and TSM (r = 0.42) computational analyses (p < 0.001, n = 469). At day four, the TSM computational analysis and the ‘standard’ showed that an experimental dentifrice containing 5% calcium sodium phosphosilicate produced more occlusion than controls (p < 0.0001). These studies refute the null hypothesis that there is no association between DH, tooth wear and the patency of the dentine tubules. Accurate techniques were developed to measure DH.
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Cruwys, Elizabeth. "Tooth wear patterns in modern human populations." Thesis, University of Cambridge, 1987. https://www.repository.cam.ac.uk/handle/1810/272343.
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Swenson, Brendon James. "Interproximal tooth wear: an in vitro pilot study." Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/2641.
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Objective: The purpose of this study was to develop a method of accurately quantifying the wear facet, and relating the wear facet size to the forces applied by the Iowa Tooth Wear Machine.
Methods: Ten un-erupted third molars were used for this study. The teeth were mounted in the Iowa Tooth Wear Machine with opposing proximal surfaces. Samples were run with a 0.250mm stroke length for 645,120 cycles under 5 pounds of weight. An optical scanner was used to digitize the initial and final interproximal wear facets. AnSur© software (Regents, University of Minnesota) was used to process and analyze the interproximal surfaces in terms of area (mm2), volume (mm³), and depth (µm).
Results: All samples were subject to identical magnitude and frequency of forces. The results show that there was considerable variation in volume loss between the samples. Results show similar amounts of volume loss in samples 3, 4, 6, 7, 8, 9, and 10 with 1, 2, and 5 showing a considerably greater amount of wear.
Conclusions: The results suggest that there may be other compounding factors involved with facet formation, and the force magnitude and frequency alone does not determine the volume of enamel loss.
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Smith, Nicholas Rindels. "Interproximal tooth wear: an in vivo pilot study." Thesis, University of Iowa, 2011. https://ir.uiowa.edu/etd/1084.
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The purpose of this pilot study was to develop a method to quantify the surface area of interproximal wear facets present in the human dentition. Another aim was to investigate the reliability of this method and possible correlations between the amount of interproximal tooth wear and vertical craniofacial morphology. The study was carried out on 24 adolescent individuals immediately prior to orthodontic treatment. Following interproximal contact separation of one week, interproximal impressions were taken with polyvinyl siloxane and a positive stone model was fabricated with type IV dental stone. The model of the wear facet was imaged using a computer-operated optical scanner and the border of the wear facet was digitally traced. From the digital tracing, the surface area of the wear facet was calculated. The intra-observer reliability of this method showed a strong agreement in repeated measurements, however the inter-observer reliability revealed some statistically significant differences between two examiners. The limited sample size could not reveal a significant relationship between interproximal tooth wear and vertical craniofacial morphology. This study serves as a proof of concept study from which further in vitro and in vivo research can be conducted to better understand the relationship between masticatory input (as measured by interproximal wear) and craniofacial morphology.
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Clement, Anna. "Tooth wear patterns in Neanderthals and early modern humans." Thesis, University College London (University of London), 2008. http://discovery.ucl.ac.uk/1445215/.
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The overall aim of this project is to investigate adaptive mechanisms involved in the evolution of Neanderthal and Modern Human face morphology. This is done by using a new method to summarise tooth wear patterns in a large collection of Late Pleistocene and Early Holocene hominins. This pattern is interpreted as an indicator of the forces habitually placed on different parts of the dentition. As the characteristic Neanderthal facial morphology is often interpreted as an adaptation to strong bite force between the anterior teeth, it is hypothesised that they should be particularly heavily worn in Neanderthals, relative to the rest of the dentition. The results presented here show that all Late Pleistocene hominins had heavily worn anterior teeth and that this was more pronounced in the Modern Humans than in the Neanderthals. There was, however, a characteristic Neanderthal pattern with wear more evenly spread between anterior teeth, whereas in Modern Humans it was more strongly concentrated in the incisors. In recent hunter-gatherers teeth were an integral part of the toolkit, strongly reflected in tooth wear. Both Neanderthals and the Skhul-Qafzeh Modern Humans shared a Middle Palaeolithic technology, with a small range of tool types and heavy anterior tooth wear, but the much more variable Upper Palaeolithic toolkit did not result in a reduction. Variation between different regions however suggests that the differences are complex Epipalaeolithic, Mesolithic and Neolithic jaws showed a reduction in the contrast between anterior and cheek tooth wear, as might be expected with the large technological changes they represent. A preliminary study was made of dental casts from Canadian Inuit whose ages and sexes were recorded. They showed much heavier anterior tooth wear than any archaeological groups. This pattern was established early in life and women had much stronger anterior wear than men. This was related to sexual division of labour and it is striking that in Neanderthals the situation seems to have been replicated.
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Milosevic, Alexander. "Tooth wear in young people : prevalance and risk factors." Thesis, University of Liverpool, 1994. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385305.
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Hooper, Susan Mary. "Tooth wear associated with dietary factors and its prevention." Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687416.
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Tooth wear is now reported in large numbers of children and young adults, and this is predominantly thought to be related to enamel and dentine erosion. Changes in diet, lifestyle and social behaviour are all considered to contribute to this concerning trend in young dentitions. This dissertation investigates methods for measuring tooth wear in vitro and in situ, studies the effects of erosion and abrasion on enamel and dentine, and explores ways to limit the damaging effects of these processes. The literature review considers the structure of normal dental tissues and the consequences of tooth wear before reviewing enamel and dentine erosion in greater detail, together with ways of addressing this condition for the benefit of future generations. Ten published works are included in this dissertation. Classic methodology for in situ erosion studies was improved and also applied to combine assessment of abrasion and erosion. Results of studies undertaken confirmed the erosive potential of conventional and modified citric and malic acid based fruit juices, acid based fruit drinks, sports drinks and acidic fruit flavoured coatings on chewing gum. The erosive effect of acid based fruit drinks was shown to be reduced by adding calcium [at both room and elevated temperatures], or adding calcium with maltodextrin, or adding calcium with phosphate at room temperature. Further studies showed protection against an erosive challenge in situ, by an experimental fluoride-based toothpaste containing sodium hexametaphosphate, and the benefit of a low RDA [relative dentine abrasivity] paste on dentine. Finally, two studies confirmed the anti-erosive properties of stannous-containing sodium fluoride toothpaste compared with competitor formulations. Conclusions from the work in this dissertation are that acidic based fruit drinks can be beneficially modified to reduce enamel and dentine erosion and that additional protection can be gained from the use of customised anti-erosion toothpastes.
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Ribeiro, Isabel Margarida Eirô de Carvalho Vaía. "Desgaste Dentário de causa erosiva: revisão bibliográfica." Master's thesis, [s.n.], 2014. http://hdl.handle.net/10284/4402.
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina DentáriaO desgaste dentário é designado como a perda do tecido duro dentário não provocado por cárie dentária, traumatismos ou defeitos de desenvolvimento. É uma alteração irreversível, progressiva e cumulativa em que a anatomia dentária fica comprometida. Existem três causas possíveis para o desgaste dentário: a atrição, a abrasão e a erosão, sendo muitas vezes um processo multifatorial. Os fatores atuam sequencialmente, sinergicamente e aditivamente e é difícil atribuir uma só causa a uma condição existente. Dada a crescente incidência e prevalência da erosão dentária, optou-se por abordar exclusivamente este fator de desgaste dentário. O desgaste dentário erosivo caracteriza-se como sendo uma perda da estrutura dura por um processo químico não bacteriano. Os ácidos que atingem, primeiramente, a superfície mais superficial do dente não são produto da flora oral, mas podem ter origem extrínseca, a partir de alimentos, medicamentos ou até mesmo devido a determinadas profissões que estão expostas a fatores de risco; intrínseca, como os distúrbios gastroesofágicos, distúrbios alimentares ou outras patologias causadoras do vómito; ou idiopática, sem causa conhecida. A exposição ao ácido, por si só, não constitui uma condição para que obrigatoriamente se inicie ou progrida a erosão dentária. A suscetibilidade individual depende de fatores biológicos e também comportamentais capazes de modular o risco para a erosão dentária. A intervenção clínica face à perda estrutural implica o controlo dos fatores etiológicos nomeadamente dietéticos, comportamentais e patológicos, associado a medidas preventivas/terapêuticas de reforço da estrutura dentária. Em casos mais severos de alteração estética e/ou funcional há que reabilitar a estrutura dentária perdida. Pretendeu-se com este trabalho sistematizar a abordagem clínica ao desgaste erosivo, de forma a facilitar o seu diagnóstico e a atuação clínica. Para tal esquematizou-se uma ficha clínica capaz de guiar o médico dentista e facilitar a sua decisão. Foi efetuada uma pesquisa na B-on, Medline/PubMed e em livros, de informação válida sobre o tema. Não se interpôs limitação temporal e usaram-se as seguintes palavras-chave na seleção de artigos: tooth wear, dental erosion, tooth wear treatment, treatment, composites. O planeamento preciso das condutas preventivas e reabilitadoras a adotar perante o desgaste erosivo é decisivo para se obter uma resolução eficaz e duradoura. Quando há uma necessidade de reabilitar a estrutura perdida, a opção deverá ser o menos invasiva possível, com um resultado o mais previsível possível e com o mais elevado nível de aceitação pelo paciente. Com este intuito foi descrita uma técnica para reabilitação de casos severos de desgaste dentário erosivo. The tooth wear is designated as the loss of dental hard tissue, which is not caused by dental cavity, trauma or developmental defects. It is an irreversible, progressive and cumulative change that compromises the dental anatomy. There are three possible causes of tooth wear: attrition, abrasion and erosion and it is often a multifactorial process. The factors act sequentially, synergistically and additively and it is difficult to attribute a single cause to an existing condition. Due to the increasing incidence and prevalence of dental erosion, it was decided to focus attention on the tooth wear exclusively. The erosive tooth wear is characterized as a loss of the hard structure by a non-bacterial chemical process. The acids that first reach the most superficial surface of the tooth are not the product of the oral flora. They may have extrinsic origin from food, medicines or even due to certain occupations that are exposed to risk factors; intrinsic origin, such as gastroesophageal disorders, eating disorders or other diseases causing vomiting; or idiopathic, without a known cause. A simple exposure to the acid is not a first priority to start or progress to dental erosion. The individual susceptibility depends on biological factors and also on behavioral factors, which are able of modulating the risk for dental erosion. The clinical intervention caused by the structural loss implies the control of etiological factors particularly dietary, behavioral and pathological factors associated with preventive/therapeutic measures to strengthen the tooth structure. In more severe cases of aesthetic and/or functional change, it is necessary to rehabilitate the lost tooth structure. The aim of this study was to systematize the clinical approach to erosive wear in order to facilitate its diagnosis and clinical performance. So a clinical record was sketched up to guide the dentists and facilitate their decision. It was carried out a research on B-on, Medline / PubMed and on books with a reliable information on the topic. There was not a temporal limitation and it was used the following keywords: tooth wear, dental erosion, tooth wear treatment, treatment, composites. The accurate planning of preventive and rehabilitative behaviors to be adopted in the erosive wear is a decisive factor to achieve an effective and lasting resolution. When there is a need to rehabilitate the lost structure, the option should be the least invasive as possible, with a more predictable result as possible and with the highest level of patient acceptance. With this purpose it was described a technique for the rehabilitation of severe cases of erosive tooth wear.
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White, Andrew John. "The biophysical chemistry of tooth surfaces : protein and peptide-based technologies for inhibiting erosive tooth wear." Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.550331.
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Dental erosion is an increasing problem in many countries around the world, and research in this field has increased dramatically in recent years. Dental erosion is the dissolution of tooth tissues by acids that are not of bacterial origin; most commonly these originate from the diet. Methods to reduce erosion are of great import; the application of milk-derived proteins such as casein and casein-derived proteins are of current interest as anti-erosion agents and are the subject of the work presented here in this thesis. The efficacy of casein and casein-derived proteins as agents to inhibit dissolution of hydroxyapatite in simple citric acid solutions are investigated in chapters 3 and 4 with two different in vitro models. It was found that these proteins inhibit hydroxyapatite dissolution over a range of erosion timescales, concentrations and exposure times. The effect of an in vitro formed salivary pellicle is also examined and the proteins were shown to retain their efficacy. The efficacy of these proteins to inhibit the earliest stages of erosion (surface softening) and more progressed stages of erosion (bulk tissue loss) are investigated in chapter 5 using atomic force microscopy nanoindentation and non-contact optical profilometry respectively. It was found that again these proteins inhibit both surface softening and bulk tissue loss of bovine enamel. The nature of the protective mechanism due to casein is investigated in chapter 6 using a range of complementary, inter-disciplinary techniques such as atomic force microscopy, x-ray reflectometry and sodium dodecyl sulphate polyacrylamide gel electrophoresis. The protective effect is ascribed to a thin protein film, of 6.6 nm in thickness, forming on the mineral surface. In conclusion, casein and casein-derived proteins are shown to have anti-erosion properties and potential as oral healthcare products.
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Ahmed, Khaled. "Quantitative analysis of tooth wear in-vivo using 3D scanning technology." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5148/.
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Aim: The primary aim of this study was to develop, calibrate and assess a novel methodology that employs 3D scanning technology in quantifying the progression of tooth wear and then assess the applicability and validity of this methodology in-vivo through clinical monitoring of the progression of tooth wear in patients over a period of 12 months. Methods and materials: A Stainless Steel Model (SSM) was fabricated consisting of seven stainless-steel ball-bearings embedded in a horseshoe-shaped base. The dimensions of the SSM were ascertained using a Coordinate Measuring Machine (CMM). The CMM calibrated SSM was used to identify the accuracy and precision of a contact stylus profilometer scanner and a non-contact class-II laser arm-scanner. The next stage involved using the SSM to identify the initial dimensional accuracy of Type IV dental stone casts poured from impressions of the SSM, using 3 types of impression materials: alginates (Alg), polyethers (PE) and polyvinylsiloxanes (PVS), and the dimensional stability of the dental stone over a period of one-month. Thereafter, the overall 3D scanning system performance was calculated. A clinical study involving tooth wear patients, recruited through 3 Restorative Dentistry Consultants’ New Patient clinics, was also carried-out. At initial visit and after 1 year, PE impressions were taken of participants’ dentition and poured. At 1 month post-pouring, the casts were 3D-scanned. The resultant scans of initial visit casts and after 1 year casts were 3D analysed, compared and differences detected. Results: The contact scanner demonstrated greater accuracy and precision compared to the non-contact scanner. Alg-fabricated casts demonstrated the largest discrepancy, producing undersized casts. PVS was the most accurate but concurrently demonstrated greater statistical variance compared to PE. The overall 3D scanning system performance, when comparing 2 individual contact scans taken of Type IV stone casts poured from PE impressions then scanned at one-month post-pouring, was 66μm. Clinically, all participants in this study presented with tooth wear greater than 140μm in depth; however, detected tooth wear only affected a limited surface area of anterior teeth. Conclusion: In this pilot study, we were able to formulate a novel descriptive 3D scanning methodology for quantifying tooth wear that accounts for the various factors affecting 3D scanning in-vivo. We have also demonstrated the clinical applicability of the methodology in monitoring the rate of tooth wear progression in patients.
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Alaraudanjoki, V. (Viivi). "Erosive tooth wear and associated factors in Northern Finland Birth Cohort 1966." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526217802.
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Abstract The aim of this study was to investigate the status of erosive tooth wear (ETW) in Finnish middle-aged adults and its association with dental caries and sociodemographic and intrinsic factors. In addition, we performed a genome-wide association study (GWAS) to identify whether genetic polymorphism (single nucleotide polymorphism) could explain some of the individual variance in the ETW status. Another aim of the study was to validate the use of the erosion index, the Basic Erosive Wear Examination (BEWE), on 3D models. Of the total Northern Finland Birth Cohort (NFBC1966), a convenience sample of 3,181 people was invited for an oral health examination in 2012–2013, of whom 1,962 participated, thus comprising the study group for the present study. ETW was assessed by sextants using the BEWE index. The clinical data was supplemented by information collected by means of postal questionnaires in 1997–1998 and 2012–2013, blood samples, and 3D models of the dentition. Of those clinically examined, 586 participants were randomly selected for the validation study of the BEWE index on 3D models. ETW was a common finding among the Finnish adult population, and almost half of the population needed at least preventive measures against the condition, and almost one in ten had severe ETW. Male gender and restorative treatment need due to dental caries were associated with ETW, unlike sociodemographic factors. Of the intrinsic factors, daily reflux symptoms and hyposalivation were the most significantly associated with severe ETW. According to the results from the GWAS, susceptibility to ETW could be partly explained by genetic polymorphism. The BEWE index was found reliable for recording ETW clinically and on 3D models, and 3D models were especially sensitive in detecting initial ETW. In conclusion, ETW seems to be common among Finnish adults, especially among males. In addition to risk factors, individual susceptibility should be kept in mind when assessing the risk for the condition. Early diagnosis of ETW is important in maintaining good oral health, and the BEWE seems to be a reliable index for that purpose both clinically and on 3D modelsTiivistelmä Tutkimuksen tavoitteena oli selvittää hampaiden erosiivisen kulumisen yleisyyttä ja vakavuutta suomalaisilla keski-ikäisillä aikuisilla, sekä erosiivisen kulumisen yhteyttä hampaiden reikiintymiseen sekä sosiodemografisiin ja sisäisiin tekijöihin. Lisäksi selvitettiin koko genomin kartoitusta hyödyntäen, voidaanko geneettisellä polymorfismilla (yksittäisillä emäsparin vaihdoksilla) selittää yksilön alttiutta erosiiviselle kulumiselle. Tutkimuksen tavoitteena oli myös validoida erosiivista kulumista arvioiva indeksi (The Basic Erosive Wear Examination, BEWE) 3D-malleilla. Koko Pohjois-Suomen vuoden 1966 syntymäkohortista kutsuttiin 3 181 henkilöä suun terveystarkastukseen vuosina 2012–2013. Kutsutuista 1 962 osallistui tutkimukseen muodostaen lopullisen tutkimusjoukon. Erosiivista kulumista arvioitiin käyttäen BEWE-indeksiä. Kliinistä tutkimusta täydensivät vuosina 1997–1998 ja 2012–2013 tehdyt postikyselyt, verinäytteet ja hampaiston 3D-mallit. Kliinisesti tutkituista osallistujista yhteensä 586 henkilöä valittiin satunnaisesti BEWE-indeksin validointitutkimukseen 3D-malleilla. Erosiivinen kuluminen oli yleistä suomalaisilla aikuisilla, ja lähes puolella oli erosiivista kulumista, joka vaatisi vähintään ennaltaehkäiseviä toimia. Vakavaa erosiivista kulumista on lähes joka kymmenennellä. Miessukupuoli ja korjaavan hoidon tarve hampaiden karioitumisen vuoksi olivat yhteydessä erosiiviseen kulumiseen, toisin kuin sosiodemografiset tekijät. Sisäisistä tekijöistä päivittäiset reflux-oireet ja vähäinen syljeneritys olivat vahvimmin yhteydessä vakavaan erosiiviseen kulumiseen. Koko genomikartoituksen perusteella vaikuttaa siltä, että alttius erosiiviselle kulumiselle saattaa selittyä osittain geneettisellä polymorfismilla. BEWE-indeksi näyttää olevan luotettava menetelmä niin kliinisessä arvioinnissa kuin arvioitaessa erosiivista kulumista 3D-malleilla. Alkava erosiivinen kuluminen oli helpommin havaittavissa 3D-malleilta kliiniseen arviointiin verrattuna. Tutkimuksen perusteella voidaan sanoa, että erosiivinen kuluminen on yleistä suomalaisilla aikuisilla, etenkin miehillä. Jo tiedettyjen riskitekijöiden lisäksi yksilöllinen alttius erosiiviselle kulumiselle tulisi pitää mielessä riskikartoitusta tehdessä. Erosiivisen kulumisen aikainen diagnosointi on tärkeää hyvän suun terveyden ylläpitämiseksi, ja BEWE-indeksi vaikuttaa soveltuvan diagnosointiin niin kliinisesti kuin 3D malleillakin
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Springbett, Susan. "Tooth wear in the deciduous dentition : a cross cultural and longitudinal study /." Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09DM/09dms769.pdf.
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Bergseth, Ellen. "On tribological design in gear tooth contacts." Doctoral thesis, KTH, Maskinelement, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102742.
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The correct tribological design will have a considerable effect on a gear’s service life and efficiency. The purpose of this thesis is to clarify the impact of variation in the gear tooth flank tribological system on the gear contact load capacity – to increase the understanding of how surface topography and lubricant interact. In this thesis the variation in surface topography inherent in the manufacturing method has been shown, by experimental work and computer simulations, to be an important factor for the contact condition in the early life of gears. Surface analysis revealed that the formation and composition of surface boundary layers depends strongly on the chemical composition of the lubricant, but also on pre-existing surface boundary layers. Additionally, surface boundary layers play a major role in frictional behaviour, wear and in allowing the lubricant to react properly with the surfaces. Paper A presents the current ISO 6336 calculation of surface durability. A robust design approach was used to investigate the extent to which the current standard for calculation of surface durability allows for manufacturing variations and the choice of lubricant. Paper B investigates the extent to which a logarithmical profile modification can increase gear contact pressure robustness compared to traditional lead profiles for gears. Paper C compares different gear manufacturing methods and their as-manufactured (fresh unworn) surface topographies, using measured surface topographies as input to a contact simulation program. Paper D examines surface boundary layer formation and the corresponding wear in relation to different anti-wear additives in an environmentally adapted base oil. Papers E and F make use of specimens with surface topographies imitating two gear manufacturing methods (grinding and superfinishing) to be used in a twin-disc and barrel-on-disc machine respectively. The contacts are analysed by friction measurements and simulations combined with methods for surface analysis.QC 20120925
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Kaidonis, John Aristidis. "An experimental study of the wear characteristics of human enamel during tooth grinding /." Title page, contents and preface only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phk126.pdf.
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Ramalho, Ilana Santos. "Avaliação clínica dos fatores etiológicos das lesões cervicais não cariosas." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/25/25146/tde-24112015-093233/.
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O propósito desta pesquisa foi investigar a influência de diferentes fatores etiológicos na formação das lesões cervicais não cariosas (LCNCs). Essas lesões foram identificadas e classificadas de acordo com o grau de severidade e correlacionadas com os seguintes fatores: presença/ausência de facetas de desgaste e de biofilme, idade, gênero, hábitos alimentares, história médica, hábitos de higiene oral e hábitos parafuncionais. Foram avaliados 33 estudantes de graduação e pós-graduação, com idade variando entre 18 e 30 anos. A avaliação clínica constou de aplicação de índice de biofilme dental, exame clínico para identificação de LCNCs e de modelos de gesso para identificação de facetas de desgaste e aplicação de questionário. Os resultados mostraram que 25 indivíduos (75,7%) apresentaram, pelo menos, uma LCNC, com maior prevalência nas faces vestibulares, sendo os primeiros molares com maior número de lesões, seguidos pelos primeiros pré-molares; os incisivos foram os dentes com menor número de lesões; os pré-molares foram os dentes que apresentaram lesões com maiores escores de severidade; encontrou-se correlação direta entre a severidade das lesões e a idade (p=0,04; r=0,350) e entre facetas de desgaste e lesões (p<0,05; r=0,605). Dos 250 dentes com lesões cervicais, 217 (86,8%) apresentaram facetas de desgaste e 33 (13,2%) não apresentaram facetas, o que sugere a existência de relação significativa entre a presença de facetas e de lesões (p<0,05); foi encontrada, também, correlação inversa entre a presença de biofilme e o número e a severidade das lesões (p=0,02,r=-0,403; p=0,02; r=-0,426, respectivamente). Os fatores gênero, hábitos alimentares, história médica, hábitos de higiene oral e hábitos parafuncionais não foram diferenciais com relação à presença de LCNCs. Os resultados obtidos reforçam a teoria multifatorial para a etiologia dessas lesões.The purpose of this research was to investigate the influence of different etiological factors in the formation of noncarious cervical lesions (NCCLs). These lesions were identified and classified according to the degree of severity and correlated with the following factors: presence/absence of wear facets and biofilm, age, gender, dietary habits, medical history, oral hygiene habits and parafunctional habits. Thirty-three undergraduate and graduate students were evaluated, with ages ranging from 18 to 30 years. Clinical evaluation consisted of dental biofilm index application, clinical examination to identify NCCLs and stone casts for identification of wear facets and questionnaire. The results showed that 25 individuals (75.7%) had at least one NCCL, with higher prevalence in buccal surfaces, the first molars with the higher number of lesions, followed by the first premolar; incisors were teeth with fewer lesions; premolars were teeth that had lesions with higher severity scores; direct correlation was found between severity of lesions and age (p=0.04, r=0.350), and between wear facets and lesions (p<0.05, r= 0.605); from 250 teeth with cervical lesions, 217 (86.8%) had wear facets and 33 (13.2%) had no facets, which suggests the existence of a significant relationship between the presence of facets and NCCLs (p<0.05); inverse correlation was found between the presence of plaque and the number and severity of NCCLs (p=0.02, r=- 0.403; p=0.02, r=-0.426, respectively). Gender, dietary habits, medical history, oral hygiene habits and parafunctional habits showed no significant differences regarding to the presence of NCCLs. The results support the multifactorial theory for the etiology of these lesions.
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Gillborg, Susanna. "Orofacial pain and tooth wear in swedish adults : cross-sectional studies in southern Sweden." Licentiate thesis, Malmö universitet, Odontologiska fakulteten (OD), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-7757.
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Aim. The present licentiate thesis investigated the prevalence of TMDpainand related factors, the prevalence and severity of tooth wear, andthe etiology and factors related to tooth wear in adults in southern Sweden.Methods. The methods used included a questionnaire, history, clinical examination,intraoral photographs, and saliva sample. In Paper I, twoscreening questions for TMD pain were used to query a study samplecomprising 6123 questionnaire participants about their pain experience.In Paper II, a clinical examination and intraoral photographs helped determinethe presence and severity of tooth wear. Information from a questionnaire,patient histories, and participant saliva samples were analyzedregarding tooth wear-related factors. The study sample comprised 831 individuals.Results. Paper I found a prevalence of TMD pain once a week or moreoften in 11% of the study sample. Related factors were female gender,subjects under 50 years of age, weekly headache, self-reports of poor generalhealth, impaired oral health-related quality of life, and tooth wear.Paper II showed tooth wear in all individuals. Attrition, the most commontooth wear, was found in over 90% of the study sample. Signs of erosionwere found in almost 80% of the individuals. Men had more tooth wearthan women, but none of the factors that were investigated as related factorsdiffered between the genders. Only some of the individuals, includingthe group with severe tooth wear reported having received information about tooth wear from their clinician. Participants reported receiving informationabout tooth wear due to extensive tooth brushing more thanabout erosion.Conclusions. Paper I found a prevalence of TMD pain in 11% of the studysample. In Paper II, attrition was found in over 90% of the study sample.Almost 80% of the individuals exhibited signs of erosion. Only a few reportedhaving received information about tooth wear due to erosion fromtheir clinician.
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Zanatta, Rayssa Ferreira. "Influência de tensoativos sobre o efeito protetor da película e interação com NaF no desenvolvimento da erosão dental /." São José dos Campos, 2016. http://hdl.handle.net/11449/148581.
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Orientador: Alessandra Bühler BorgesBanca: Carlos Rocha Gomes Torres
Banca: Sérgio Eduardo de Paiva Gonçalves
Banca: Ana Carolina Magalhães
Banca: Tais Scaramucci Forlin
Resumo: A erosão dental é um processo multifatorial que envolve a desmineralização do esmalte/dentina pela ação química de ácidos extrínsecos ou intrínsecos. A película adquirida é um filme, livre de bactérias, que cobre os dentes e atua como barreira de difusão ou membrana permeável seletiva, prevenindo o contato direto de ácidos com a superfície dos dentes. Os dentifrícios, normalmente usados no controle do biofilme bucal, possuem agentes tensoativos, que podem influenciar na adsorção de proteínas salivares, e atuar diretamente na formação da película adquirida e na liberação de fluoretos para o meio bucal. Assim, verificou-se a ação destes agentes na formação e proteção da película adquirida, sua interação com fluoreto de sódio (NaF) no esmalte, e consequentemente sua interferência na proteção contra a erosão dental. Foram testados três tensoativos (Lauril Sulfato de Sódio - LSS, Tween 20 - T20 e Cocoamidopropil Betaína - CAPB), em duas concentrações (1,0% e 1,5%). A água foi utilizada como controle negativo. Amostras de esmalte bovino foram submetidas a um modelo de des/remineralização com ácido cítrico durante 5 dias, imersão em saliva humana para formação de película adquirida e em soluções com os tensoativos testados, associados ou não ao NaF (275 ppm). A solução de NaF foi utilizada como controle positivo. A análise da energia de superfície do esmalte foi determinada por goniometria e a formação de película adquirida quantificada por espectroscopia (FTIR). A erosão inicial fo... (Resumo completo, clicar acesso eletrônico abaixo)
ABSTRACT: Dental erosion can be defined as a multifactorial process that induces tooth dissolution by intrinsic or extrinsic acids. Acquired pellicle is a film, free from bacteria, that covers all tooth tissues, and acts as a selective membrane that prevents direct contact of the acids with enamel/dentin surface. Dentifrices, frequently used in the biofilm control, have some constituents, such as surfactant agents, which influence on the adsorption of salivary proteins, and may directly affect the formation of salivary pellicle and the fluoride release on oral environment. Thus, it was verified the influence of surfactants over the protective effect of the acquired pellicle, and on the interaction of fluoride with enamel. Three different surfactants were tested (Sodium Lauryl Sulphate - SLS, Tween 20 - T20 and Cocoamidopropyl Betaine - CAPB), in 2 different concentrations (1.0% and 1.5%). Water was used as negative control. Bovine enamel samples were selected and submitted to an in vitro des/remineralization model with citric acid during 5 days, immersion in human saliva for acquired pellicle formation and immersion in the surfactant solutions, associated or not with sodium fluoride (NaF - 275ppm). A NaF solution was used as positive control. The surface wettability was determined by contact angle between water and the enamel using a tensiometer, and the acquired enamel pellicle formation was assessed using a spectrophotometer (FTIR). Initial erosion was defined by microhardness at the first cycle day (measured after the first acid, after treatment and after the second acid), and the structure loss was determined by profilometry. The KOH-soluble fluoride was also quantified after the end of the cycle. The surface energy analysis showed that only SLS and CAPB in both concentrations decreased the contact angle between enamel and water. Regarding..(Resumo completo, clicar acesso eletrônico abaixo)
Doutor
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Johnson, Nathan Warren. "A cross-sectional in vivo pilot study on the relationship between interproximal wear and facial form." Thesis, University of Iowa, 2012. https://ir.uiowa.edu/etd/2905.
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The main goal of this pilot study was to determine if a correlation was present between interproximal wear rate and facial form and/or interproximal wear surface area and facial form. Additionally, interproximal wear was evaluated with regards to salivary pH. VPS impressions of interproximal tooth surfaces were captured in 29 adolescent volunteers after orthodontic separation and prior to band placement. A positive replica was created using a type IV die stone. The subsequent die stones were scanned, analyzed and interproximal wear surface area measurments were calculated. Correlation tests revealed that there was no clear or consistent relationship between interproximal wear and facial form and interproximal wear and salivary pH. Methodological limitations were discussed and potential changes for future research were presented.
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Mullan, Francesca. "The role of 3D surface texture measurement of natural human enamel for assessment of erosive tooth wear." Thesis, King's College London (University of London), 2018. https://kclpure.kcl.ac.uk/portal/en/theses/the-role-of-3d-surface-texture-measurement-of-natural-human-enamel-for-assessment-of-erosive-tooth-wear(acb0c6cd-b91b-4b88-a955-199ee8e0d1a8).html.
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This thesis investigated the role of 3D surface roughness measurement for the quantification of erosive tooth wear. The aim of this thesis was to develop a method for quantifying 3D surface roughness changes occurring in natural unpolished enamel and polished enamel during erosion. Firstly, an in vitro erosion model was developed for quantifying mechanical and optical surface changes of natural unpolished enamel during dietary erosion through a series of pilot studies. Following this a series of validation studies were conducted to identify measurement error (measurement noise, accuracy, precision and software errors) when quantifying surface texture of complex biological structures using optical profilometry. The measurement protocol was validated for measuring 3D roughness over different locations across natural unpolished enamel and polished enamel samples by comparing the results of imaging five central areas (each 0.004 mm2) over the apex of the curvature of the sample, in comparison to measuring 20 peripheral areas (each 0.004 mm2) in order to reliably measure surface roughness. The optimised surface texture measurement protocol was then used to quantify surface roughness changes of natural and polished enamel from in vitro three cycle erosion regimes (15, 30 and 45 minutes) using a commercially available orange juice drink. Finally, an in situ investigation into the effects of the 15, 30 and 45 minutes of erosion times was conducted with acid immersion occurring both ex vivo and in vivo. The initial work suggested significant reduction in Sa roughness of natural unpolished enamel following 45 minutes of erosion in orange juice from median (IQR) 0.62 (0.27) μm to 0.38 (0.06) μm (P < 0.01). Subsequent validation studies revealed no significant differences between the median (IQR) Sa roughness of the central 1.45 (2.58) μm and peripheral areas 1.32 (4.86) μm before erosion for natural unpolished enamel, and whilst the median (IQR) roughness significantly decreased to 0.38 (0.35) μm and 0.34 (0.49) μm respectively (p < 0.0001) there were no significant differences between measuring the centre or peripheral areas. For polished enamel, there were no significant differences across the sample with 0.04 (0.17) μm for central and 0.05 (0.15) μm for the peripheral areas before erosion. Whilst Sa roughness significantly increased after erosion to 0.27 (0.08) μm (p < 0.0001) there were no significant differences between measuring the central or peripheral areas. When investigating three erosion times in vitro there were only significant changes in natural unpolished enamel after 45 minutes of erosion: median (IQR) Sa roughness decreased from 0.50 (0.29) μm to 0.42 (0.14) μm (P < 0.05). Whereas, median (IQR) Sa of polished enamel significantly increased for all three erosion times from 0.08 (0.10) μm to 0.26 (0.02) μm (p < 0.001) (15 minutes), 0.15 (0.11) μm to 0.25 (0.07) μm (p < 0.001) (30 minutes) and 0.10 (0.08) μm to 0.27 (0.04) μm (p < 0.001) (45 minutes). Finally, the in situ study demonstrated no significant changes in Sa roughness of natural unpolished enamel regardless of either erosion time or whether exposure was ex vivo or in vivo. However, mean (SD) Sa roughness of polished enamel significantly increased for all three erosion times from 0.04 (0.01) μm to 0.09 (0.03) μm (p < 0.05) (15 minutes ex vivo), 0.04 (0.01) μm to 0.12 (0.04) μm (p < 0.05) (30 minutes ex vivo), 0.04 (0.01) μm to 0.13 (0.04) μm (p < 0.05) (45 minutes ex vivo), 0.04 (0.02) μm to 0.08 (0.04 μm) (p < 0.05) (15 minutes in vivo), 0.04 (0.01) μm to 0.10 (0.04) μm (p < 0.05) (30 minutes in vivo) and 0.04 (0.01) μm to 0.07 (0.03) μm (p < 0.05) (45 minutes in vivo). By optimising the measurement protocol in the early part of the thesis 3D (Sa) enamel surface texture was quantified over different locations of the natural unpolished enamel. This confirmed that the roughness of the central area of unpolished enamel samples was representative of the overall sample which allowed reliable measurements from this area in future studies. This central area of the samples represented the apex of curvature and thus provided the least data drop out from the optical scanners and was also in the region of more homogenous natural prism morphology. The in vitro investigation of the different erosion times identified that not only was natural unpolished enamel more resistant to erosion than polished samples but moreover natural enamel behaved differently to polished enamel by becoming smoother following erosion rather than rougher. The protocol developed for the in situ study successfully provided further confirmation of the resistance of unpolished natural enamel when the natural inhibitory effects of the oral environment were combined. This demonstrated the positive effects of natural resistance to erosive tooth wear. Therefore, this thesis has developed a method for quantifying 3D surface roughness changes occurring in natural unpolished enamel and polished enamel during erosion, which revealed significant complexity in the surface texture response of natural unpolished enamel to a dietary erosive challenge.
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Saxin, Jenny, and Maria Persson. "Dental erosion. Hur vanligt är det blad barn och ungdomar?" Thesis, Malmö högskola, Odontologiska fakulteten (OD), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-19787.
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Coca cola och sportdrycker är båda drycker som idag konsumeras i stora mängder världen över. Erosionskador på tänderna är vanligare än vad många tror eller ens vet om. Både vuxna och tonåringar dricker stora mängder erosiva drycker utan att veta om dess skador på tänderna. Dessa drycker börjar oftast drickas i tonåren men konsumtionen fortsätter sedan långt upp i åldrarna. Tandslitage är tandsubstansförlust som inte är av kariogen påverkan. En typ av tandslitage är erosionsskador som vanligen definieras som en substansförlust av emaljen genom en kemisk process där bakterier inte påverkar processen.Syftet med denna studie är att redogöra för hur vanliga erosionsskador är bland barn och ungdomar i åldersgruppen 12-18-år.PubMed samt Tandläkartidningens hemsida har använts som sökmotorer för vetenskapliga artiklar. Vid sökning i PubMed användes sökorden Dental erosion och Tooth erosion, där 2348 respektive 1989 träffar hittades. Vid urval av relevanta artiklar har titlar och abstract screenats samt har inklusions- och exklusionskriterier använts.I det här examensarbetet har det fastställts att prevalensen av erosionsskador varierar i olika områden (geografiskt), mellan olika åldrar- och kön. I studierna framkom varierande resultat på förekomst av erosionsskador. Prevalensen i procent förekom från 7,2- till 51 procent. Utifrån de studier vi funnit kan ingen egentlig slutsats dras eftersom inga enhetliga studier har utförts samt att de åldersgrupper som studerats (10-15 år) inte motsvarar den åldersgrupp som är beskriven i syftet.
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Werner, Mathias. "Theoretical and experimental studies of a single tooth milling process." Doctoral thesis, KTH, Industriell produktion, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104443.
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The industrial development of metal cutting processes in gear manufacturing aims at continuously increasing productivity, including increased tool reliability. Basically, the parameters that have an influence on the cutting processes should be known and possible to control. Gear manufacturing is highly important for the automotive industry. The prevalent manufacturing method is gear hobbing with hobs consisting of solid Powder Metallurgical High Speed Steel (PM HSS) with Physical Vapor Deposited (PVD) coatings. The hob teeth have to be reconditioned before wear reaches such levels that the gear quality becomes impaired. Such wear often results in a total breakdown of the tool. One crucial reason for this is that hobbing processes for the present often lack reliability; which makes it difficult for the gear manufacturers to predict the tool wear on the hob teeth and decide when the tool should be replaced in order to avoid severe damages. A consequence of catastrophic tool wear is that it leads to an instantaneously changed geometry of the cutting edge, which in turn implies that the machined gears do not comply with the stipulated properties on the machined gear products. A single tooth milling test (STMT) with tools of PM-HSS in a conventional milling machine has been developed in this research project, aiming at characterizing the effect of tool preparation on the type of wear mechanism. The experience and conclusions from these tests may probably be transferred to real PM-HSS hob tooling (HT). The advantages of such a test, compared to a real gear hob test, are primarily the cost reductions and time saving aspects with respect to both the design and the manufacturing of the cutting teeth The research presented in this thesis is based on experimental investigations and theoretical studies of significant parameters, i.e. the surface roughness and edge rounding, contributing to the robust and reliable design of a PM-HSS cutting tool. The research work has in addition to, the development of the milling test method, also comprised development of measuring methods and a simulation model based on the Finite Element Model (FEM).QC 20121105
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Taylor, R. M. S. (Richard Morris Stovin), and n/a. "Anatomy and biology of tooth dislocation and wear in the pre-European Maori and Australian Aborigine : with supporting publications." University of Otago. School of Dentistry, 1991. http://adt.otago.ac.nz./public/adt-NZDU20070627.105619.
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Summary: Some 250 Australian aboriginal skulls were studied to ascertain differences in tooth dislocation and wear in this ethnic group as compared with those manifested in the pre-European Maori, with consideration of the differences in cultural and botanical background as contributing factors. Other features were studied, including the crowding of anterior teeth, the incidence of caries and abscesses, and of mottled enamel and tooth fracture.
Aspects of physical anthropology and biology were found to be relevant to this study, since they offered explanations for some previously unsolved problems such as edge-to-edge bite, and crowding of incisors in well-formed jaws.
The work is supported by 28 illustrations of the dentition selected from various sources, and described in the text.
Reprints of 18 other published papers reporting various dental studies of relevance to the above major publication are included in this presentation.
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O'Toole, Saoirse. "An investigation into the relationship between dietary acid intake, oral hygiene procedures and the progression of erosive tooth wear." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/an-investigation-into-the-relationship-between-dietary-acid-intake-oral-hygiene-procedures-and-the-progression-of-erosive-tooth-wear(bf14d4db-35be-4914-a1dd-4054b4c9c293).html.
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This thesis investigated conveniently selected factors that may influence the progression of erosive tooth wear. The designs were a laboratory study, casecontrol study and a RCT evaluating the influence of dietary advice on progression. The effect of timing of fluoride application with a previously reported erosive challenge was investigated in vitro. Human enamel samples (n=80) were treated with 225ppm stannous or sodium fluoride, either before or after a citric acid challenge (0.3%). The mean step heights (SD) for stannous fluoride applied before and after erosion were 3.2μm (0.57) and 4.2μm (0.7) respectively and these were statistically significantly lower than sodium fluoride application (before: 8.2μm (0.65) and after: 7.5μm (0.85), p < 0.001). Stannous fluoride resulted in least step height when applied before erosion and sodium fluoride after erosion. A validated questionnaire assessed commonly reported dietary and tooth brushing habits on a convenient sample of 300 participants with severe erosive tooth wear and 300 controls in a case-control study. The frequency of dietary acid intake between meals had the strongest association with erosive wear (OR 3.83-14.86, p < 0.001). No association was observed with tooth brushing after an erosive challenge when dietary factors were controlled for. A randomised controlled trial assessed the impact of enhanced dietary advice (n=28) on severe erosive tooth wear progression compared to standard of care advice (n=29). Addition-silicone impressions and questionnaires were taken at baseline and 6 months later. Impressions were cast in dental stone, scanned using laser profilometry and superimposed using surface matching software. The dietary intervention group reduced daily frequency of acid intake between meals by three intakes (IQR 1, 3) compared to one intake (IQR 0, 3) for controls, p=0.048. The intervention group also demonstrated reduced volume loss per surface (0mm3 (IQR -0.18, 0.18)) compared to controls (-0.06mm3 (IQR -0.24, 0.11), p=0.045). These studies suggest that prevention should focus on limiting dietary acid consumption between meals.
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Dias, José Manuel Carvalho. "Abordagem terapêutica do paciente bruxómano." Master's thesis, [s.n.], 2015. http://hdl.handle.net/10284/5138.
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina DentáriaO bruxismo é uma atividade parafuncional, noturna ou diurna, caracterizada pelo ato, subconsciente e não funcional de apertar e ranger os dentes. Estima-se que a sua prevalência na população adulta ronde os 8-10%, sendo o bruxismo diurno o mais prevalente, comparativamente ao noturno e o género feminino o mais afetado por este tipo de bruxismo. O presente trabalho teve como propósito rever algumas das opções terapêuticas reabilitadoras, utilizadas nestes pacientes, e averiguar qual delas apresenta os melhores resultados clínicos, ao longo dos anos. Realizou-se uma pesquisa bibliográfica, onde se limitou o intervalo de tempo a artigos entre 2004 e 2014, tendo-se no entanto, recorrido a um artigo de 2002 e a uma tese de mestrado, que se revelaram pertinentes para a revisão em causa. Dos 36 artigos consultados, 18 correspondem a revisões bibliográficas, 18 a casos clínicos, uma tese de mestrado e 2 livros. A bibliografia revela-se inconclusiva quanto à melhor abordagem reabilitadora a seguir, focando-se nos riscos inerentes a cada reabilitação e cuidados a ter, em cada caso, mediante a opção selecionada. Sendo a escolha, principalmente baseada nas expectativas do paciente e condição económica. No entanto, sendo o bruxismo uma parafunção complexa multifatorial, parece unânime que a sua abordagem terapêutica necessite de uma equipa multidisciplinar, que permita não só a reabilitação da dentição desgastada, como uma abordagem direcionada para a diminuição dos estímulos desencadeantes, sinais e sintomas, permitindo uma maior longevidade das mesmas. No entanto, são necessários mais estudos, com desenhos e limites bem definidos, para que se consiga chegar a conclusões mais coerentes. Bruxism is a parafunctional activity which can occur during sleep as well as during wakefulness, characterized by unconscious and unfuntional teeth grinding or clenching. It’s estimated that its prevalence, in the general adult population, is about 8-10%, being the wakefulness bruxism the most prevalent and the female gender more affected. With this work we purpose to review some rehabilitative treatment options, used in these patients, and determine which had the best clinical results over the years. A literature search was performed and most of the papers selected were published between 2004- 2014, apart from one which was published before, but of additional value for our review. Of the 36 papers selected, 18 of them were review articles, 18 were clinical cases, one a master thesis and 2 books. The literature is inconclusive in determine which is the best rehabilitation option in this cases, being just stated the major risks and cautions we need to have in which of them. Moreover, the choice is mainly based on patients expectations and economic condition. As bruxism is a multifactorial parafuntional, with no specific treatment, is believed that is needed a multidisciplinary team for its management, so that the focus is not only in the type of rehabilitation but also in reduce the adverse effects of the habit. There is still insufficient evidence to support or refute a certain type of rehabilitation and treatment therefore, more studies are needed, with clear drawings and limits so that we can get more consistent and specific outcomes.
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Derceli, Juliana dos Reis. "Avaliação do efeito da associação da irradiação laser Er:YAG com flúor no esmalte dental submetido à erosão." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/58/58133/tde-04022011-135157/.
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A erosão dental é uma lesão causada pela dissolução mineral do esmalte, através da ação de ácidos oriundos do suco gástrico ou da alimentação. O objetivo deste estudo foi avaliar a eficácia do laser Er:YAG na prevenção da erosão do esmalte associado ou não ao flúor e avaliar alterações químicas e morfológicas do esmalte após os tratamentos preventivos. Para tanto, foram obtidos 95 espécimes a partir de esmalte bovino (4x4mm), os quais foram planificados, polidos e divididos aleatoriamente em 5 grupos de acordo com os tratamentos preventivos realizados (G1- laser Er:YAG; G2- laser + flúor; G3- flúor + laser; G4- laser simultaneamente flúor; G5- flúor). A metade da superfície do esmalte de cada espécime foi isolada com esmalte cosmético e cera utilidade (área controle) e a outra metade exposta ao tratamento superficial. O laser foi irradiado por 10 segundos, sem refrigeração, modo focado, não contato, 4 mm de distância focal e 60 mJ/cm2 e 2Hz, o gel fluoretado foi aplicado por 4 minutos. O desafio erosivo ocorreu em Coca-Cola à temperatura ambiente, 4x/dia, por 1 minuto, durante 5 dias. O grau de desmineralização do esmalte foi avaliado por meio da microscopia óptica, do desgaste e da microdureza, as alterações químicas e morfológicas através da MEV/EDS. Os dados da microscopia óptica e microdureza foram analisados por meio da Análise de Variância a 1 Critério, para o desgaste foi utilizado o método não-paramétrico Kruskal-Wallis e para a MEV/EDS foi realizada a análise descritiva dos dados. Nos resultados da microscopia óptica observou-se que os grupos 3 e 4, F+L e FeL respectivamente, apresentaram menor desmineralização em relação aos demais grupos, nos resultados do desgaste observou-se que os grupos 4 e 5, FeL e F respectivamente, apresentaram menor desgaste, os grupos 2 e 3 apresentaram maior desgaste e o grupo 1 foi semelhante ao grupo 4. Os resultados de dureza não demonstram diferença estatística entre os grupos, tendo ocorrido diminuição da dureza em relação ao grupo controle, exceto pelo o grupo L. Na análise da EDS o grupo 5 (FeL) apresentou maior retenção de flúor, cerca de 174%, seguido pelos grupos 4 (F) e 3 (F + L), os quais aumentaram o conteúdo de flúor em 27% e 10% respectivamente, os grupos 1 (L) e 2 (L+F) apresentaram diminuição do conteúdo de flúor de 39% e 7,5%, respectivamente. Todos os grupos apresentaram diminuição do conteúdo de Ca e P, exceto o grupo 2 (L+F). Na MEV observou-se áreas ablacionadas. Concluí-se a irradiação laser utilizada simultaneamente à aplicação tópica de flúor foi capaz de promover maior retenção de flúor ao esmalte dental, menor desmineralização e desgaste do esmalte dental, o emprego do flúor isoladamente e do flúor aplicado simultaneamente ao laser proporcionaram menor desgaste do esmalte, o laser Er:YAG promoveu ablação superficial do esmalte quando irradiado com fluência de 60mJ/cm2, 2Hz e sem refrigeração.The dental erosion is a lesion caused by loss of enamel mineral due to the acids action originated from gastric juice or dietary. The aim of this study was to evaluate the effectiveness of the Er:YAG laser on the prevention of enamel erosion associated or not to the fluoride, and to evaluate chemical and morphological changes of enamel after preventive treatments. Thus, 95 bovine enamel samples (4X4 mm) were ground flat, polished and randomly divided into 5 groups according to the preventive treatments: G1- Er:YAG laser; G2- laser + fluoride; G3- fluoride + laser; G4- laser simultaneously fluoride; G5- fluoride. Half of the enamel surface was covered with nail varnish and wax (control area) and the other half exposed to the treatments. The laser was irradiated (focused mode, without water cooling, 10 s, 60 mJ/2Hz and focal distance of 4mm) and the fluoride gel was applied for 4 min. Each specimen was individually exposed to soft drink Coca-Cola 4 times/day, during 1 minute, for 5 days. It was evaluated the enamel demineralization degree (optical microscopy), wear depth (perfilometer) and microhardness. Chemical and morphological alterations were evaluated by SEM/EDS. Optical microscopy and microhardness data were analyzed by one-way ANOVA, for wear depth was used Kruskal-Wallis non-parametric method and for SEM/EDS was performed descriptive data analysis. For optical microscopy, G3 and G4 presented lower demineralization than the other groups; for wear, G4 and G5 exhibited lower values, G2 and G3 presented higher values and G1 did not differ from G4. The microhardness results did not show statistical difference among the groups. Microhardness decreasead in relation to the control group, except for G1. In the EDS analysis, G5 presented higher fluoride retention, about 174%, followed by G4 and G3 which increased the fluoride content in 27% and 10% respectively, G1 and G2 presented decrease of the fluoride content of 39% and 7.5% respectively. All the groups presented decrease of the Ca and P content, except G2. In the MEV, ablated areas were observed. It can be concluded that laser irradiation used simultaneously to the fluoride was able to promote higher fluoride retention to enamel, lower demineralization and wear. The use of the fluoride alone and fluoride applied simultaneously to the laser provided lower wear. The Er:YAG laser caused enamel superficial ablation when irradiated with 60mJ/cm2 fluence, 2 Hz, and without refrigeration.
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Soares, Ana Flávia. "Comprometimento do esmalte bovino após escovação em função do condicionamento ácido, clareamento ativado com luz híbrida, concentração e pH dos géis clareadores." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/25/25148/tde-05042013-145654/.
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Este estudo in vitro avaliou a influência do clareamento ativado com luz híbrida, em função da variação do pH e concentração de géis clareadores, e do condicionamento ácido prévio do esmalte bovino na alteração da rugosidade e desgaste após escovação simulada. Fragmentos de esmalte (1,5cm x 0,5cm x 0,4cm) foram divididos em duas partes, ficando uma metade como controle e a outra como área teste. Esta última foi subdividida em duas metades, sendo que uma recebeu o condicionamento ácido somado ao gel clareador e a outra somente o gel clareador. Os espécimes foram divididos aleatoriamente em seis grupos (n=10): C = controle; TBO35LH = Total Blanc Office 35% 1 sessão (5x8) + ativação com luz híbrida LED/Laser; LPS35LH= Lase Peroxide Sense 35% - 1 sessão (5x8) + ativação com luz híbrida LED/Laser; LPS25LH = Lase Peroxide Sense 25% - 1 sessão (5x8) + ativação com luz híbrida LED/Laser; LPL15LH = Lase Peroxide Lite 15% - 1 sessão (5x8) + ativação com luz híbrida LED/Laser; LPL10LHV = Lase Peroxide Lite 10% - 1 sessão (5x8) + ativação com luz híbrida LED/Laser violeta. A rugosidade aritmética (Ra) inicial, após clareamento e após escovação, foi determinada pela média (μm) de três leituras (em cada área sem e com ácido totalizando seis leituras por espécimes) com o rugosímetro Hommel Tester T 1000. Os valores médios do pH foram determinados pelo peagômetro digital Sentron Model 1001 nos tempos inicial e final. Os espécimes foram armazenados em saliva artificial por sete dias, submetidos a 100.000 ciclos de escovação simulada. Após 24 horas o desgaste superficial foi determinado (μm) empregando o mesmo rugosímetro. Em relação ao desgaste e a alteração de rugosidade superficial, os resultados foram submetidos à Anova a dois critérios e a dois critérios de medidas repetidas e posteriormente ao teste de Tukey. Os dados obtidos das leituras de pH foram submetidos à ANOVA a um critério e a dois critérios de medidas repetidas e ao teste de Kruskal Wallis e Tukey para comparações individuais entre os grupos. Para todos os testes o nível de significância foi de 5%. A rugosidade e o desgaste apontaram diferenças estatísticas entre os grupos, principalmente quando comparado à área com e sem ácido. Os géis clareadores apresentaram tendência de diminuição dos valores de pH do tempo inicial para o tempo final, contudo, uma correlação com a rugosidade e com o desgaste não pôde ser estabelecida de forma clara.This in vitro study evaluated the influence of whitening activated with hybrid light on the function variations of the pH level and concentration of bleaching gels and prior acid etching of bovine enamel and the change in roughness and wear after simulated tooth brushing. Fragments of enamel (1.5 cm x 0.5 cm x 0.4 cm) were divided into two parts, one half as the control and the other as the test area. The latter was divided into two halves, one of which received the etching added to the whitening gel and the other with only the whitening gel. The specimens were randomly divided into six groups (n = 10): C = control; TBO35LH = 35% Total Blanc Office 1x session (5x8\') + activation with hybrid light LED/Laser; LPS35LH = 35% Lase Peroxide Sense - 1x session (5x8\') + activation with hybrid light LED/Laser; LPS25LH = 25% Sense Lase Peroxide - 1x session (5x8\') + activation with hybrid light LED/Laser; LPL15LH = 15% Lase Peroxide Lite - 1x session (5x8 \') + activation with hybrid light LED/Laser; LPL10LHV = 10% Lase Peroxide Lite - 1x session (5x8\') + activation with violet hybrid light LED/Laser. The arithmetic roughness (Ra) started after bleaching and after brushing was determined by averaging (μm) the three readings (in each area - with and without acid for a total of six readings per specimen) with a Rugosimeter Hommel Tester T 1000. The mean pH values were determined by the Sentron Model 1001 digital pH meter at the start and end times. The specimens were stored in artificial saliva for seven days, and subjected to 100,000 cycles of simulated brushing. After 24 hours, the surface wear was determined (μm) employing the same roughness meter. In relation to the change in wear and surface roughness, the results were evaluated by two way ANOVA testing for repeated measures and later, a Tukey\'s test. The data obtained from the pH readings were submitted to two way ANOVA testing for repeated measures and the Kruskal Wallis and Tukey tests for the comparisons between the individual groups. The significance level was set at 5% for all the tests. The roughness and wear showed statistical differences between the groups, especially when compared to the area with and without acid. The bleaching gels tended to decrease in pH from the starting time to the final time, however, a correlation with the roughness and wear could not be clearly established.
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Rocha, Cristiane Tomaz. "Influência do laser de CO2 associado ao fluoreto estanhoso no controle da erosão induzida por ácido clorídrico em esmalte de dentes decíduos-análise do desgaste e da permeabilidade." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/58/58135/tde-04022011-112259/.
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Diante da importância e prevalência da erosão em crianças, devido principalmente ao refluxo gastroesofágico e da ausência de estudos na literatura sobre os efeitos do laser de CO2 no controle da erosão induzida por ácido clorídrico, o objetivo deste estudo foi determinar a influência in vitro de diferentes potências do laser de CO2 associado ao fluoreto estanhoso a 0,4% no controle da erosão induzida por ácido clorídrico em esmalte de dentes decíduos, por meio da análise do desgaste e da permeabilidade. Sessenta dentes decíduos foram utilizados para a obtenção de 120 fragmentos de esmalte (3x3 mm). Os fragmentos foram planificados, polidos e montados em blocos de resina acrílica. Duas fitas adesivas foram colocadas na superfície, deixando uma área de 3x1mm2 exposta. Para a formação das lesões de erosão, os espécimes foram submetidos a um desafio ácido de 4 ciclos por 2 minutos cada, com solução de ácido clorídrico a 0,01 M (pH 2). A análise do desgaste inicial foi calculada por perfilometria óptica e usada para selecionar 104 espécimes. Estes foram aleatoriamente divididos em 8 grupos, de acordo com a aplicação de flúor (presente- gel de fluoreto estanhoso a 0,4% e ausente-controle) e potência do laser de CO2 (sem irradiação-controle, 0,5 W, 1 W, 1,5 W). Metade dos espécimes foram submetidos a uma única aplicação do gel fluoretado por 1 minuto com o auxílio de um microbrush. A irradiação com laser de CO2 foi realizada no modo ultrapulso, duração do pulso de 100µs e desfocado a uma distância de 4 mm do esmalte. Após a realização dos tratamentos, desafios erosivos sucessivos foram realizados durante 5 dias, utilizando o mesmo protocolo descrito anteriormente. A análise do desgaste final foi calculada por perfilometria óptica. Para análise da permeabilidade, os espécimes foram submetidos a um método de coloração histoquímica, utilizando-se soluções de sulfato de cobre e de ácido rubeânico. Da região delimitada, obtiveram-se secções que foram digitalizadas sob microscopia óptica e submetidas à avaliação da penetração de íons cobre em relação à espessura total do esmalte. Foram realizadas, em cada secção, cinco avaliações da penetração dos íons cobre, totalizando quinze leituras por espécime. Os dados da análise do desgaste foram submetidos a ANOVA a dois critérios e a interação entre os fatores aplicação de flúor e potência do laser de CO2 foi significativa (p = 0,046). Entretanto, pela análise da permeabilidade, a ANOVA a dois critérios não mostrou interação entre os fatores (p = 0,591). Efeito significativo do fator potência do laser de CO2 foi observado (p = 0,037), sendo que a potência de 1,5 W proporcionou aumento da permeabilidade do esmalte quando comparado a 0,5 W. A correlação entre as análises do desgaste e permeabilidade não foi significativa (p = 0,699). Conclui-se, pela análise do desgaste, que o laser de CO2 com 1W associado ao fluoreto estanhoso a 0,4% pode ser um método efetivo no controle da erosão induzida por ácido clorídrico em esmalte de dentes decíduos. A análise da permeabilidade não evidenciou sinergismo entre a aplicação de fluoreto estanhoso a 0,4% e as potências do laser de CO2. A potência do laser de CO2 de 0,5 W proporcionou menor permeabilidade no esmalte erodido quando comparada a de 1,5 W. A análise do desgaste não apresentou correlação com a análise da permeabilidade em esmalte de dentes decíduos submetidos a desafios erosivos por ácido clorídrico.Facing importance and prevalence of erosion in children, mainly due to gastroesophageal reflux and absence of studies evaluating effects of CO2 laser in control erosion induced by hydrochloric acid, the aim of this study was to determine in vitro influence of different CO2 laser powers associated with 0.4% stannous fluoride erosion control induced by hydrochloric acid on enamel of primary teeth by wear and permeability analysis. Sixty primary teeth were used to obtain 120 enamel fragments (3x3 mm). Fragments were flatenned, polished and fixed in resin blocks. Two piece of tapes were placed on the surface, leaving an exposed area 3x1mm2. For the formation of erosion lesions, specimens were submitted to an acid challenge by 4 cycles of 2 minutes each, with 0.01 M hydrochloric acid solution (pH 2). Initial wear analysis was calculated by optical profilometry and used to select 104 specimens. These were randomly assigned into 8 groups according to fluoride application (present-gel 0.4% stannous fluoride and absent-control) and CO2 laser power (no irradiation control, 0.5 W, 1 W, 1.5 W). Half of specimens were submitted to a single fluoride application for 1 min with microbrush. CO2 laser irradiation was performed in a ultrapulsed, 100µs pulse duration at a distance of 4 mm of enamel. After treatments, erosive challenges were performed for 5 successive days using the same protocol described above. Final wear analysis was calculated by optical profilometry. For permeability analysis, specimens were submitted to histochemical coloring method, using copper sulphate and acid rubeanic solutions. It was obtained sections from exposed area which were scanned under light microscopy and evaluated for copper ions penetration in relation to the total thickness of enamel. In each section, five evaluations of copper ions penetration were performed, resulting in fifteen readings per specimen. Data wear analysis were submitted to two-way ANOVA and interaction between factors fluoride application and CO2 laser power was significant (p = 0.046). However, permeability analysis, two-way ANOVA showed no interaction between factors (p = 0.591). Significant effect of CO2 laser power was found (p = 0.037), and 1.5 W power provided an increase of enamel permeability compared to 0.5 W. Correlation between wear and permeability analysis was not significant (p = 0.699). CO2 laser using 1W associated with 0.4% stannous fluoride can be an effective method to erosion control induced by hydrochloric acid on enamel of primary teeth. Permeability analysis showed no synergic effect between 0.4% stannous fluoride application and CO2 laser powers. CO2 laser power of 0.5 W provided the lowest permeability of enamel erosion compared to 1.5 W. Wear analysis showed no correlation with permeability analysis of primary teeth enamel submitted to erosion by hydrochloric acid challenges.
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Domare, Emma. "Generating gear grinding : An analysis of gringing parameters's effect on gear tooth quality." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-68637.
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Generating gear grinding is a method used for hard machining of gearbox gears. It facilitates a productive gear manufacturing with tight tolerances regarding surface roughness and geometrical accuracy. However, if the grinding is done with incorrect parameters, so called grinding burns can arise with consequences such as changes in surface hardness, changes in residual stress levels, surface embrittlement and compromised fatigue strength. This thesis investigates the gear tooth quality resulting from grinding parameters contributing to an improved grinding time. A literature study will cover gear geometries and material, grinding wheel properties, influences by grinding parameters and several verification methods. An experimental test will then be used to put four different grinding parameters to the test. The results showed that an increased cutting speed indicated finer surface roughness andincreased Barkhausen noise but showed no influence on gear geometry. Increasing both rough and fine feed rates resulted in a minor increase in geometry deviation but no significant difference in surface roughness. Large variations within the different verification method results related to grinding burns madeit difficult to draw conclusions regarding the experimental factors chosen. However, several factors apart from the experimental ones varied in the testing were believed to have significant influence, such as the flow of the cooling fluidand the amount of retained austenite from the carburizing process. In fact, the trends which seemed to be connected to these factors could be seen in both Barkhausen noise analysis, hardness measurementsand microstructure.
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Contente, Marta Maria Martins Giamatei. "Ação triboquímica do ciclo mastigatório na resistência ao cisalhamento de resinas compostas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/58/58135/tde-25112013-082956/.
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Este trabalho avaliou in vitro a ação de estímulos triboquímicos que simulam o ciclo mastigatório na resistência ao cisalhamento de duas resinas compostas Filtek P90®- 3M ESPE (P) e Z250®-3M ESPE (Z) com e sem presença de contaminação salivar, assim como a liberação de íons e a qualidade e a quantidade do desgaste produzido. A amostra foi composta por 12 grupos experimentais (n=5): P1 e Z1, sem contaminação/contra dente decíduo; P2 e Z2, com contaminação/contra dente decíduo; P3 e Z3, sem contaminação/contra dente permanente; P4 e Z4, com contaminação/contra dente permanente; P5 e Z5 sem contaminação (controle); P6 e Z6 com contaminação (controle). Ensaios de tribocorrosão foram efetuados na configuração pino-placa de deslizamento linear alternativo, na presença da solução de saliva artificial, carga de 3N e frequência de 1Hz, totalizando 900 ciclos de desgaste durante 15 minutos. As pistas de desgaste foram caracterizadas por MEV, EDX e XRD e o volume de desgaste por análise da variação de massa. A MEV demonstrou que os grupos Z apresentaram maior quantidade de desgaste quando comparados aos grupos P e que os antagonistas de dente permanente apresentaram maior quantidade de resíduos do material desgastado que os antagonistas em dentes decíduos. A análise por XRD não apresentou variação na caracterização de nenhuma das amostras quando se comparou os espécimes antes e após a realização dos experimentos. Na análise por EDX observou-se picos correspondentes aos elementos Ítrio e Silício para os antagonistas dos grupos P e de Zircônia para os dos grupos Z. Os dados obtidos pelo ensaio de nanoendentação não apresentaram diferença estatisticamente significante para nenhum dos grupos estudados (ANOVA e Teste de Duncan p≤0,05). Nenhuma diferença estatisticamente significante foi encontrada pelos corpos de prova em resina composta ou antagonistas em nenhum dos grupos estudados quando da análise da variação de massa. Os valores de resistência ao cisalhamento foram: P1 11,20 (±1,44); P2 9,28 (±1,88); P3 8,94 (±1,03); P4 5,76 (±1,47); P5 17,50 (±3,28); P6 15,31 (±1,19); Z1 12,17 (±1,56); Z2 9,60 (±1,56); Z3 10,79 (±3,33); Z4 9,14 (±2,06); Z5 9,77 (±2,27) e Z6 9,22 (±1,98). Os valores de resistência ao cisalhamento foram menores para os grupos P submetidos à contaminação salivar. Na análise de ICP-MS maior liberação de íons Cálcio foi constatada em todos os grupos. A liberação de íons Fosfato foi observada na solução resultante do ensaio tribológico do corpo de prova em resina composta P90 contra antagonista dente permanente. Conclui-se que não há alterações químicas na superfície das resinas após o ensaio mecânico de desgaste e a resina composta P90 apresentou os menores valores de resistência ao cisalhamento em comparação com a resina Z250. A contaminação salivar interferiu negativamente nos valores de resistência ao cisalhamento quando a resina composta P90 foi avaliada. Dente utilizado como contra corpo não teve sua superfície alterada pela incorporação de resíduos de desgaste da resina composta, mantendo o módulo de elasticidade e a nanodureza, sendo que o desgaste ocorreu de forma mais acentuada nas restaurações de resina composta Z250. A liberação de íons Cálcio foi maior que a de íons Fosfato em todas as situações analisadas e a liberação de íons Fosfato foi maior na situação em que o corpo de prova em resina composta P90 foi submetido ao ensaio tribológico contra antagonista dente permanente. O ciclo mastigatório interferiu na resistência ao cisalhamento da resina composta P90.This study evaluated in vitro the action of tribochemical stimuli simulating the masticatory cycle on the shear bond strength of two composite resins Filtek P90®- 3M ESPE (P) and Z250®-3M ESPE (Z) - with and without salivary contamination, as well as the release of ions and the quality and amount of composite resin/tooth wear. Twelve experimental groups (n=5) were formed: P1 and Z1, without contamination/against primary tooth; P2 and Z2, with contamination/against primary tooth; P3 and Z3, without contamination/against permanent tooth; P4 and Z4, with contamination/against permanent tooth; P5 and Z5, without contamination (control); P6 and Z6, with contamination (control). Tribocorrosion assays were performed using the pin-on-plate configuration under linear reciprocating sliding, in the presence of an artificial saliva solution and under 3 N load and 1 Hz frequency, totalizing 900 wear cycles during 15 minutes. The wear was characterized by SEM, EDX and XRD analyses and the wear volume was determined by mass variation analysis. The SEM analysis showed that the Z groups presented less wear than the P groups, and that the permanent tooth antagonists presented more worn material residues than the primary tooth antagonists. The XRD analysis did not reveal variation in the characterization of any of the samples, comparing the specimens before and after the experiments. The EDX analysis revealed peaks corresponding to the elements yttrium and silicon for the P groups\' antagonists and zircon for the Z groups\' antagonists. Data from the nanoindentation test did not show statistically significant difference for any of the groups (ANOVA and Duncan test p≤0.05). For the mass variation analysis, no statistically significant difference was found between the composite resin specimens or antagonists in any of the groups. The shear bond strength results were: P1 11.20 (±1.44); P2 9.28 (±1.88); P3 8.94 (±1.03); P4 5.76 (±1.47); P5 17.50 (±3,28); P6 15,31 (±1.19); Z1 12.17 (±1.56); Z2 9,60 (±1.56); Z3 10.79 (±3.33); Z4 9.14 (±2.06); Z5 9.77 (±2.27) and Z6 9.22 (±1.98). The shear bond strength values were lower in the P groups subjected to salivary contamination. The ICP-MS analysis revealed greater calcium ion release in all groups. Regarding phosphate ion, greater release was observed in the solution resulting from the tribological assay when the P90 composite resin specimens were tested against permanent tooth antagonists. In conclusion, there were no chemical alterations on resin surface after the mechanical wear assay and P90 composite resin presented lower shear bond strength values than Z250 composite resin. Salivary contamination affected negatively in the shear bond strength values when P90 resin composite was evaluated. Teeth used as counterbody did not have their surface altered by the incorporation of composite resin wear residues, maintaining the modulus of elasticity and nano-hardness, and the wear was more accentuated in the Z250 composite resin restorations. There was greater release of calcium ions compared with phosphate ions in all analyzed situations and the release of phosphate ions increased when P90 was subjected to tribological assay against a permanent tooth antagonist. Tribochemical stimuli simulating the masticatory cycle interfered with the shear strength of composite resin P90.
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Lopes, Marcia Cristina. "Estudo longitudinal do desgaste dentário em adolescentes." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/23/23148/tde-16042015-101538/.
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Com o controle da cárie dentária em muitos países e a permanência por mais tempo do elemento dentário na cavidade bucal, o desgaste dentário começou a despertar atenção da comunidade científica. Considerando os poucos estudos que abordam a incidência e progressão do desgaste em adolescentes, o objetivo deste estudo foi investigar a prevalência, incidência e a progressão do desgaste dentário em adolescentes de 15 anos de idade, estudantes de Rio Grande da Serra - São Paulo. A progressão do desgaste também foi estudada, associada com as variáveis independentes: gênero, fatores socioeconômicos (renda familiar e escolaridade da mãe) e ausência de elemento dentário na cavidade bucal. O primeiro exame foi realizado com 203 adolescentes entre os meses de outubro e novembro de 2011, e o reexame realizado após um ano e meio contando com 121 adolescentes. O desgaste dentário foi avaliado pelo índice de desgaste dentário (de Carvalho Sales-Peres). Uma cirurgiã-dentista previamente calibrada com o padrão ouro mostrou concordância de 80% e resultado do teste Kappa0,78 (+ 0,03). O resultado intra examinador obtido foi de 93% de concordância e teste Kappa 0,90 (+ 0,08). Nos dois exames, o desgaste dentário acometendo apenas o esmalte foi o mais comum, no entanto o desgaste em dentina foi observado em 2,1% das superfícies no primeiro exame passando para 8,6% no segundo exame e, 55,4% das superfícies não sofreram modificações entre os dois exames. A progressão do desgaste dentário acometendo a dentina foi de 6,6% das superfícies. Estudantes com renda familiar inferior a três salários mínimos e com mães que estudaram até o ensino fundamental apresentaram maior progressão do desgaste para dentina. Esta progressão não foi relacionada ao gênero e nem a ausência de elemento dentário. A prevalência de desgaste das superfícies dentárias destes estudantes foi elevada, porém com baixa severidade.With the control of the dental caries in many countries and the permanence for more time of the dental elements in the oral cavity, the tooth wear started to attract the attention of the scientific community. Considering the few studies that have approached the wear incidence and progression in adolescents, the objective of this study was to investigate the prevalence, incidence and the progression of the tooth wear in 15-year-old adolescents who study in Rio Grande da Serra - São Paulo. The wear progression was also studied and associated with the independent variables: gender, socioeconomic factors (family income and the mother\'s education level) and the absence of the dental element in the oral cavity. The first examination was conducted with 203 adolescents between October and November of 2011, and the re-examination was conducted one year and a half later counting with 121 adolescents. The tooth wear was evaluated through the dental wear index (de Carvalho Sales-Peres). A dental surgeon previously calibrated with the gold standard showed a concordance of 80% and the result of the Kappa test of 0.78 (+ 0.03). The intra examiners result obtained was of 93% of concordance and the Kappa test 0.90 (+ 0.08). In both exams, the tooth wear affecting only the enamel was the most common one, however the dentin wear observed in 2.1% of the surfaces in the first exam went to 8.6% in the second exam and, 55.4% of the surfaces did not undergo modifications between both exams. The progression of the tooth wear affecting the dentin was of 6.6% of the surfaces. Students with family income lower than three minimum wages and with mothers who studied until the elementary school presented higher levels of dentin wear progression. This progression was not related to the gender neither to the absence of the dental element. Tooth wear prevalence of the dental surfaces of these students was high, however with low severity.
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Grazziotin, Gladis Benjamina. "Estudo \'in situ\' do efeito remineralizador da saliva e do flúor após profilaxia com jato de bicarbonato de sódio sobre o esmalte hígido." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/25/25133/tde-24082007-161424/.
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O objetivo deste estudo foi avaliar in situ o efeito da saliva, associada ou não ao flúor, sobre a estrutura dentária do esmalte que recebeu profilaxia prévia com jato de bicarbonato de sódio. Foram utilizados 40 blocos de esmalte de dente bovino de 4x4 mm, nos quais foi aplicado o jato de bicarbonato de sódio por 10s, simulando a realização de uma profilaxia profissional. Após essa etapa, os blocos foram divididos em dois grupos (GI e GII) e montados em dispositivos intra-bucais, os quais foram utilizados por 10 voluntários, durante dois períodos experimentais cruzados e cegos de quatro horas. Os blocos do GI foram expostos diretamente à saliva in situ, enquanto os do GII, foram expostos à saliva associada ao flúor sob forma de bochecho com solução de NaF a 0,2%, durante o minuto inicial. As possíveis alterações ocorridas na superfície do esmalte após as etapas do experimento foram avaliadas através de testes de microdureza superficial (Knoop-25g/5s) e de desgaste. Os dados de microdureza superficial foram analisados pela Análise de Variância a dois Critérios (ANOVA) e teste de Tukey (p<0,05) e os dados de desgaste pelo teste T pareado, para a diferença entre perfil inicial e final (p<0,05). Não foi encontrada diferença estatisticamente significante entre GI e GII, para as variáveis dureza e desgaste. A média de desgaste após profilaxia não apresentou diferença da média após a etapa in situ. No entanto, a média de microdureza no início, após a profilaxia e após a etapa in situ foi respectivamente: GI (340±16,6a; 329±35,7b; 354±37,8a) e GII (338±15,6a; 312 ±46,3b; 340±21,8a). Com base nos resultados encontrados pôde-se concluir que a saliva apresentou efeito semelhante a saliva associada ao bochecho fluoretado e após 4 horas de remineralização in situ não houve recuperação em altura de parte da estrutura dentária perdida devido à aplicação do jato de bicarbonato de sódio sobre o esmalte hígido.The aim of this in situ study was to evaluate the effect of the saliva, associated or not to fluoride, on the superficial enamel structure in which a sodium bicarbonate jet was applied. Forty bovine enamel specimens (4x4 mm) were subjected to sodium bicarbonate jet for 10 seconds to simulate a prophylaxis procedure. The specimens were then divided the in two groups (GI and GII) and were mounted in a intra-oral device which were used by 10 volunteers for two cross-over, blind experimental periods of 4 hours. The specimens of GI were directly exposed to saliva in situ, while those of GII were exposed to saliva associated to fluoride by mouthrinsing 0,2%NaF solution on the first minute of the experiment. The changes on the enamel surface were analyzed by superficial microhardness test (Knoop, 25g/5s) and perfilometry (wear). Two-way ANOVA and Tukey test (p<0,05) were used for microhardness data. The wear was analyzed by T pare test for the initial and final profile difference (p<0,05). There were no statistically difference between GI and GII, in respect to microhardness and wear. The mean enamel wear after sodium bicarbonate jet application was not significantly different from the enamel mean wear after the in situ phase. However the microhardness mean values at baseline, after sodium bicarbonate jet application and after in situ phase were respectively: GI (340±16.6a; 329±35.7b; 354±37.8a) e GII (338±15.6a; 312 ±46.3b; 340±21.8a). In according to the obtained results it was concluded that saliva presented the same effect on enamel recovery when compared to saliva associated to fluoride. After 4 hours of in situ remineralization, it was not observed the height recovery of the enamel, lost by wear due to the use of a sodium bicarbonate jet application.
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Santos, Nicole Marchioro dos. "Resistência de união em dentes decíduos erodidos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/152683.
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O objetivo deste estudo foi avaliar a resistência de união (RU) do esmalte e da dentina decídua após desafio erosivo utilizando sistemas adesivos convencionais e autocondicionantes. Noventa e seis molares decíduos foram seccionados mesio-distalmente para obtenção de blocos de esmalte, foram embebidos em resina epóxi e polidos com lixas de carbeto de silício (600, 1200, 2400 e 4000). As amostras foram randomizadas e divididas entre os 4 sistemas adesivos utilizados: SB (Adper Single Bond 2), SBU (Single Bond Universal), OBFL (Optibond FL) e BF (Bond Force). Metade das amostras (grupo teste, n=48) foram submetidas a desafio erosivo/abrasivo (50 mL de Coca-Cola®, pH 2,6, 1 min, 4x ao dia, 5 dias, seguido de escovação por 1 min com dentifrício fluoretado, NaF 1450 ppm e saliva artificial). A outra metade dos blocos (grupo controle) foi mantida imersa em saliva artificial. Em seguida foram realizadas restaurações de resina flow (Tetric Flow) utilizando matrizes de polivinil siloxano com diâmetro de 0,9mm e 1mm de altura. As amostras foram colocadas na máquina de ensaio universal e foi aplicada força de cisalhamento com velocidade de 1,0mm/min até que a fratura ocorresse. Os mesmos blocos tiveram suas superfícies de dentina expostas, em seguida, as mesmas etapas foram realizadas (restaurações e RU). Foram utilizados os testes ANOVA de duas vias e Tukey (p=0,05). No esmalte, os grupos teste e controle não apresentaram diferença estatística, independentemente dos sistemas adesivos utilizados. Na dentina, o BF apresentou melhores valores de no grupo teste (p=0,04). O fator adesivo foi significativo na análise fatorial (p<0,001) assim como a interação entre desafio erosivo/abrasivo e os sistema adesivo utilizado (p=0,046). Somente o substrato dentinário teve influência significativa na RU (p=0,395). Conclui-se que a RU ao esmalte decíduo não foi afetada pelo desafio erosivo/abrasivo para todos os sistemas adesivos utilizados, enquanto a RU na dentina decídua somente foi afetada pelo sistema adesivo autocondicionante contendo flúor.The aim of this in vitro study was to evaluate the microshear bond strength of four adhesive systems on eroded or sound primary teeth. Methods: Ninety-six primary molars were cut mesio-distally, embedded, ground and polished with SiC papers (600, 1200, 2400 and 4000). Specimens were randomly divided according to 4 adhesive systems: SB (Adper Single Bond2®), SBU (Universal Single Bond®), OBFL (OptibondFL®) and BF (BondForce®). Half of the specimens were exposed to erosive/abrasive challenge, and the other half (control group; n=48) remained immersed in artificial saliva. Erosive challenge consisted of specimen immersion in Coca-Cola® (pH 2.6, 50ml, 1min, 4x, 5 days). Once a day, the specimens were brushed using an electric toothbrush with a slurry (artificial saliva and NaF toothpaste, 1450 ppm) for 1 minute. Polyvinyl siloxane molds with a perforation 0.9 mm in diameter and 1 mm in height were placed over the specimens in order to build restorations with flowable resin composite. The molds were cut with surgical blades and removed to allow for microshear bond strength testing. Bonded specimens were attached to an universal testing machine and a shear load was applied with a steel wire at a crosshead speed of 1.0 mm/min until failure occurred. After the tests in enamel, dentin was exposed and polished to perform the same tests in this substrate. Two-way ANOVA and Tukey tests were performed (p=0.05). Results: No statistically significant difference was found between the eroded and sound enamel for any of the adhesives. BF was statistically significant better in eroded dentin than sound dentin (p=0.04). A factorial analysis indicated that the factor adhesive was significant (p<0.001) as was the interaction between adhesive and erosive tooth wear (p=0.046). Only the dentin substrate had a significant influence on microshear bond strength (p=0.395). Conclusion: Bond strength to primary enamel was not affected by erosive/abrasive challenge for all the adhesives systems, while in primary dentin the bond strength was affected only after the use of self-etch adhesive containing fluoride.
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Coppo, Priscilla Pessin. "Novo método para o estudo de desgaste por atrição (deslizamento alternado) em esmalte bovino, em função da carga normal e da lubrificação: redução do desgaste com gel lubrificante oral." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/23/23140/tde-21092015-152213/.
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O esmalte dental é o tecido mineralizado mais duro do corpo humano; apesar disto, seu desgaste é um problema muito comum. Este pode estar associado aos processos de envelhecimento, ou ainda, ser encontrado em indivíduos jovens, como consequência de atividades parafuncionais, por exemplo, atrição dental. Este tipo de dano pode resultar em prejuízo da função mastigatória e em diminuição da qualidade de vida. Por isto, o desgaste do esmalte dental tem sido objeto de muitos estudos, embora poucos tenham utilizado conceitos tribológicos. Não foi encontrado nenhum estudo que explorasse o desgaste de esmalte e seus micromecanismos oriundos do deslizamento alternado de incisivo contra incisivo, configuração que mais se aproxima do tribossistema real de atrição. O presente estudo tem por objeto investigar o desgaste e seus mecanismos em pares deslizantes de esmalte incisal (configuração pino-plano), selecionados por seus similares valores de dureza e de tenacidade à fratura, submetidos a diferentes cargas normais e lubrificações do meio. Incisivos bovinos foram ensaiados em deslizamento alternado sob duas cargas normais (8 N e 16 N) e quatro modos de lubrificação: saliva natural; saliva artificial; gel lubrificante oral (Oralbalance!, Biotène); e grupo controle sem lubrificação (seco). Durante os ensaios, foram levantadas as curvas de atrito. O volume desgastado e a rugosidade da superfície foram mensurados via perfilometria 3D. Os micromecanismos de desgaste foram analisados ao microscópio eletrônico de varredura. O aumento da carga normal aplicada resultou em aumento do volume de desgaste para todas as condições. Comparando-se ao grupo sem lubrificação, as salivas (natural e artificial) não reduziram o desgaste, mas a lubrificação com o gel foi efetiva para reduzir tanto o volume de esmalte desgastado como o coeficiente de atrito. A relação entre o valor do parâmetro de rugosidade Sq e o coeficiente de atrito não foi linear, nem entre a rugosidade Sq e o coeficiente de desgaste, para todas as condições. Os micromecanismos de desgaste encontrados foram, em ordem crescente de severidade: desgaste da região interprismática (8 N - gel); propagação de trincas interprismáticas (8 N - seco); reações triboquímicas associadas à ação mecânica (8 N - saliva natural e artificial; 16 N - gel; 16 N - saliva natural e artificial); e desplacamento (16 N - seco).Enamel is the hardest mineralized tissue in the human body; despite that, the enamel wear is a very common problem. The wear damage can be related to aging processes or also be found in young people as a result of parafunctional activities, for example, dental attrition. This type of damage can result in loss of masticatory function and decreased quality of life. Therefore, the wear of the enamel has been the subject of many studies, although few have used tribological concepts. The wear mechanisms of reciprocating sliding pairs from incisor against incisor have not been reported in the literature, this configuration is the one that is closest to the real tribosystem of attrition. The present study aims to investigate the wear behavior and the related mechanisms in reciprocating sliding pairs of incisal enamel (pin-on-flat configuration), selected for their similar hardness and fracture toughness values, with different applied normal loads and lubrication conditions. Bovine incisors were tested in reciprocating sliding with different applied normal loads (8 N and 16 N) and four lubrication conditions: natural saliva; artificial saliva; oral gel lubricant (Oralbalance!, Biotène); and control group (dry). During tests, the friction curves were recorded. The volume loss and the surface roughness Sq were investigated by 3D profilometry. Wear mechanisms were analyzed by scanning electron microscope. The increase of the normal load resulted in an increased volume loss for all conditions. Comparing to the group without lubrication, the saliva (natural and artificial) did not reduce the volume loss, but the lubricant gel was effective to reduce both the volume loss and the coefficient of friction. The relationship between the value of the roughness Sq and the friction coefficient was not linear, nor between the roughness Sq and the wear coefficient for all conditions. In increasing order of severity, the micromechanisms of wear were: wear at the interrod enamel (8 N - gel); crack propagation in the interrod enamel (8 N - dry); tribochemical reactions associated with mechanical wear (8 N - natural saliva and artificial saliva; 16 N - gel; 16 N - natural saliva and artificial saliva); and flake-like wear (16 N - dry).
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Assunção, Cristiane Meira. "Eficácia de diferentes dentifrícios na prevenção do desgaste dentário erosivo em dentes permanentes e decíduos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/184423.
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Os dentifrícios são veículos fundamentais para a aplicação dos fluoretos. Estudos em dentes humanos e bovinos têm mostrado que os fluoretos podem apresentar efeitos diversos na prevenção e na progressão do desgaste dentário erosivo (DDE). No entanto, pouco se sabe sobre seu efeito em dentes decíduos. Objetivo: 1) Avaliar o efeito preventivo de dentifrícios fluoretados por meio da intensidade de reflexão da superfície especular (IRS), da microdureza de superfície (MDS) e da perda da superfície calculada (PSC) utilizando um modelo inicial de erosão/abrasão; 2) avaliar por meio de perfilometria a perda de superfície (PS) em um modelo de erosão/abrasão avançado e 3) comparar esse efeito preventivo entre os dentes permanentes (DP) e dentes decíduos (dd). Material e Métodos: Amostras de esmalte de dentes permanentes (n = 100) e decíduos (n = 100) foram aleatoriamente divididos em cinco grupos (n = 20) de acordo com os dentifrícios testados: G1 – dentifrício placebo (0ppm), G2 – dentifrício com NaF (controle positivo, 1500ppm, Crest®, P & G), G3 - dentifrício anti-erosão com AmF-NaF-SnCl (1400ppm, elmex Erosion Protection®, GABA - Colgate), G4 - dentifrício com SnF (1100ppm, Sensodyne Repair&Protect®, GSK), G5 - dentifrício anti-erosão com NaF para crianças (1450ppm, Sensodyne ProNamel Junior®, GSK) Metade de cada superfície de esmalte foi coberta com resina à base de metacrilato para criar uma área hígida de referência. As amostras foram então submetidas a ciclos de erosão/abrasão, cinco no protocolo inicial e mais 25 para o protocolo avançado, totalizando 30 ciclos para este último protocolo. Em cada ciclo, as amostras foram incubadas em saliva artificial por 1h hora, submetidas ao desafio erosivo (3min; ácido cítrico 1%; pH 3.6; a 25 ° C) e à abrasão (2min de imersão no slurry; 50 movimentos de escovação; 200 g). Os efeitos das duas co-variáveis "dente" e "dentifrício" foram analisados através do teste ANOVA e as comparações entre os dentifrícios foram realizadas por meio do teste de Kruskal-Wallis e entre os tipos de dente (DP e dd) utilizando o teste de Wilcoxon, com nível de significância de 5%. Resultados: No protocolo inicial, considerando os resultados de MDS, as amostras do grupo do dentifrício placebo apresentaram valores significativamente menores para os ‘DP’ do que os outros grupos (p<0.05), no entanto sem diferença entre os dentifrícios fluoretados. Para os ‘dd’, o dentifrício placebo (G1) e o dentifrício com SnF (G4) também mostraram valores significativamente menores do que os outros grupos (p<0.05) Nos resultados de IRS, o dentifrício com SnF (G4) apresentou valores menores em ambos os tipos de dente. Além disso, os dentes decíduos apresentaram significativamente maiores valores de IRS que os dentes permanentes, exceto no grupo do dentifrício anti-erosão com AmF-NaF-SnCl (G3). Os dentes decíduos apresentaram maior PSC do que dentes permanentes, exceto no G3. No protocolo avançado de erosão/abrasão os dentes decíduos (dd) mostraram PS significativamente maior do que os dentes permanentes (DP) em todos os grupos (p <0.001). Os valores médios de PS de cada grupo foram: G1 DP 18.18μm (± 3.98), dd 25.65μm (± 9.21); G2 DP 14.76μm (± 2.82), dd 18.11μm (± 3.92); G3 DP 12.62μm (± 5.29), dd 15.61μm (± 6.70); G4 DP 17.12μm (± 2.24), dd 23.41μm (± 7.9); G5 DP 13.24μm (± 1.29), dd 18.28μm (± 8.96). Conclusões: No protocolo de erosão/abrasão inicial dentes decíduos apresentaram valores mais baixos MDS, valores de IRS mais elevados e maior PSC do que os dentes permanentes durante o experimento. O dentifrício anti-erosão com NaF para crianças apresentou os menores valores de PSC em ambos os dentes permanentes e decíduos, com um melhor efeito preventivo. No protocolo avançado o dentifrício anti-erosão com AmF-NaF-SnCl apresentou o melhor efeito preventivo contra desgaste erosivo nos dentes permanentes. Em dentes decíduos os dentifrícios com NaF (G2), anti-erosão com AmF-NaF-SnCl (G3) e anti-erosão com NaF para crianças (G5) mostraram efeito semelhante.Toothpastes are key vehicles for fluorides application. Studies have shown that various fluorides have different preventive effect on erosive tooth wear (ETW) progression. Little is known about their effect on deciduous teeth. Aim: 1) To evaluate the preventive effect of the toothpastes through surface specular reflection intensity (SRI), surface microhardness (SMH) and calculated surface loss (CSL) in an initial erosion/abrasion model; 2) to evaluate through profilometry the surface loss (SL) in a severe erosion/abrasion model and 3) to compare this preventive effect between permanent teeth (PT) and deciduous teeth (dt). Material and Methods: Enamel samples of permanent (n=100) and deciduous teeth (n=100) were randomly divided into five groups according to toothpastes tested (n=20). G1 – placebo toothpaste (0ppm), G2 – NaF toothpaste (positive control, 1500ppm, Crest®, P&G), G3 – AmF-NaF-SnCl antierosion toothpaste (1400ppm, elmex Erosion Protection®, GABA – Colgate), G4 – SnF toothpaste (1100ppm, Sensodyne Repair®, GSK), G5 – NaF antierosion toothpaste for children (1450ppm, Sensodyne ProNamel Junior®, GSK). Half of enamel sample surfaces were covered with methacrylate-based resin to create a sound reference area. The samples were submitted to erosion-abrasion cycles, 5 in initial protocol and more 25 in severe protocol, totalizing 30 cycles at the end. In each cycle samples were incubated in artificial saliva (1h), submitted to erosive challenge (3min; 1% citric acid; pH3.6; at 25°C) and to toothbrush abrasion (2min immersion in slurry; 50 strokes; 200g) The effects of the two covariables “tooth” and “toothpaste” were analyzed by ANOVA Comparisons among toothpastes were evaluated using Kruskal-Wallis-tests and between PT and dt using Wilcoxon’s rank sum test. Results: In initial protocol, considering the SMH results, placebo toothpaste showed significantly lower SMH values in PT than the other toothpastes (p<0.05), with no differences between the toothpastes. In dt, placebo and G4 also showed significantly different values than the other groups (p<0.05). In SRI results, SnF toothpaste (G4) showed lower erf values in both PT and dt. Deciduous teeth presented significantly higher SRI than permanent (p<0.05), except on AmF-NaF-SnCl antierosion group (G3). Deciduous teeth presented generally higher CSL than PT, except for G3. In the severe protocol deciduous teeth (dt) showed significant higher SL than permanent teeth (PT) in all groups (p<0.001). The mean values of SL of each group were: G1 PT 18.18(±3.98), dt 25.65(±9.21); G2 PT 14.76(±2.82), dt 18.11(±3.92); G3 PT 12.62(±5.29), dt 15.61(±6.70); G4 PT 17.12(±2.24), dt 23.41(±7.9); G5 PT 13.24(±1.29), dt 18.28(±8.96) Conclusions: In initial protocol deciduous teeth presented lower SMH values, higher SRI values and higher surface loss than permanent teeth during the experiment. The NaF antierosion toothpaste for children presented the lowest values of SL in both permanent and deciduous teeth, with a better preventive effect. In severe protocol, AmF-NaF-SnCl antierosion toothpaste showed the best preventive effect against erosion-abrasion cycles in permanent teeth. In deciduous teeth NaF toothpaste, AmF-NaF-SnCl antierosion toothpaste and NaF antierosion toothpaste for children showed similar effect.
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Aznar, Fabiano Duarte da Costa. "Desgaste dentário e perdas dentárias em pacientes eutróficos, portadores de obesidade mórbida e submetidos à cirurgia bariátrica." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/25/25144/tde-23012019-154149/.
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Este estudo teve como objetivo avaliar e comparar desgaste dentário e perda dentária de pacientes eutróficos, obesos mórbidos pré cirúrgico, operados com até 24 meses e operados com mais de 36 meses de cirurgia bariátrica. O estudo foi do tipo observacional transversal e analítico com pareamento de sexo e idade. A amostra foi composta por 240 pacientes, (GC) - pacientes eutróficos (N=60), (GO) - pacientes obesos mórbidos (N=60), (G24) - pacientes operados com menos de 24 meses (N=60) e (G36) - pacientes operados com mais de 36 meses (N=60). As variáveis que foram analisadas: sexo, raça, escolaridade, classe econômica, hipertensão, diabetes, triglicerídeos, colesterol, tabagismo, etilismo, idade, IMC, % de perda de peso, perda dentária, desgaste dentário e relação cintura-quadril. Foi aplicada a análise estatística descritiva para obter as frequências absolutas e relativas. Para verificar a associação entre obesidade e os desfechos bucais (desgaste dentário e perda dentária) foi usado o modelo de regressão linear multivariada, Odds ratio (OR) e o intervalo de confiança (IC) de 95%. Não houve diferenças estatisticamente significativas entre os grupos considerando etnia (p=0,135), escolaridade (p=0,108), triglicerídeos (p=0,078), tabagismo (p=0,568) etilismo (p=0,712), dentes perdidos (p=0,686) e o desgaste dentário tanto por sextantes, quanto total (p=0,448). Porém houve desgaste maior entre os sextantes II e V. O GO apresentou menor classe econômica (p=0,012), maior proporção de hipertensão (p<0,001), diabetes (p<0,001), colesterol (p=0,001), IMC (p<0,001) e relação cintura-quadril (p<0,001), % de perda de peso foi maior no G24 comparado ao G36 (p<0,001). Pode-se concluir que indivíduos submetidos à cirurgia Bypass Gástrico em Y de Roux, independente do período de cirurgia, apresentaram mais desgaste dentário nas superfícies incisais/oclusais, sendo que os dentes anteriores foram os mais afetados. O desgaste dentário esteve associado à idade e ao número de dentes perdidos.The aim of this study was to evaluate and compare dental wear and tooth loss of eutrophic, preoperative, morbidly obese patients operated on for up to 24 months and operated with more than 36 months of bariatric surgery. The study was crosssectional and analytical with gender and age matching. The sample consisted of 240 patients (GC) - Eutrophic patients (N = 60), (GO) - morbidly obese patients (N = 60), (G24) - patients operated on less than 24 months (G36) - patients operated on for more than 36 months (N = 60). The variables that were analyzed were sex, race, schooling, economic class, hypertension, diabetes, triglycerides, cholesterol, smoking, alcoholism, age, BMI, weight loss, dental loss, dental wear and waist-to-hip ratio. The descriptive statistical analysis was applied to obtain the absolute and relative frequencies. The multivariate linear regression model, odds ratio (OR) and 95% confidence interval (CI) were used to verify the association between obesity and oral outcomes (dental wear and tooth loss). There were no statistically significant differences between groups (p=0,135), schooling (p=0.108), triglycerides (p=0.078), smoking (p=0.568) and dental wear by both sextants and total (p=0.448). However, there was greater wear among the II and V sextants. The GO presented lower economic class (p=0.012), higher proportion of hypertension (p<0.001), diabetes (p<0.001), cholesterol (p=0.001), BMI (p<0.001) and waist-hip ratio (p<0.001), % weight loss was higher in G24 compared to G36 (p<0.001). It can be concluded that individuals submitted to the Roux-en-Y obesity surgery, regardless of the surgery period, presented more tooth wear on the incisal / occlusal surfaces, and the anterior teeth were the most affected. Dental wear was more related to age and tooth loss.
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Normando, Antonio David Corrêa. "Morfologia dentofacial e características oclusais dos índios Arara: revisitando o papel da hereditariedade e da dieta na etiologia da má oclusão." Universidade do Estado do Rio de Janeiro, 2010. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=2879.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorA influência da dieta e da hereditariedade nas características dentofaciais foi avaliada através do exame de duas populações indígenas amazônicas divididas por um processo de fissão linear. Os indígenas que constituem a aldeia Arara-Iriri são descendentes de um único casal expulso da aldeia Arara-Laranjal. O crescimento da aldeia Iriri ocorreu pelo acasalamento de parentes próximos, ratificado por um alto coeficiente de consanguinidade (F=0,25, p<0,001). A epidemiologia da má oclusão e das características da face foi analisada nos indivíduos entre dois e 22 anos, das aldeias Iriri (n=46) e Laranjal (n=130). A biometria da dentição e da face foi obtida em 55 indígenas em dentição permanente sem perdas dentárias, através da fotogrametria facial e dos modelos de gesso. O desgaste dentário foi examinado em 126 indivíduos através da análise de regressão múltipla. Os resultados revelaram uma determinação significativa da idade no desgaste dos dentes (R2=87,6, p<0,0001), que se mostrou semelhante entre as aldeias (R2=0,027, p=0,0935). Por outro lado, diferenças marcantes foram observadas nas características dentofaciais. Revelou-se uma face mais vertical (dolicofacial) entre os índios Iriri e o predomínio do tipo braquifacial nos indígenas da aldeia original, corroborado pela fotogrametria. Uma face sagitalmente normal foi observada em 97,7% da aldeia Laranjal, enquanto faces convexas (26,1%, RR-16,96) e côncavas (15,2%, RR=19,78) eram mais prevalentes na aldeia Iriri (p<0,001). A biprotrusão, com consequente redução do ângulo nasolabial, era uma característica comum entre os Arara, porém com maior prevalência no grupo Iriri (RP=1,52, p=0,0002). A prevalência da má oclusão foi significativamente mais alta na aldeia Iriri (RP= 1,75, p=0,0007). A maioria da população da aldeia original (83,8%) apresentou uma relação normal entre os arcos dentários, contudo, na aldeia resultante (Iriri), 34,6% dos indivíduos era Classe III (RP=6,01, p<0,001) e 21,7% era Classe II (RP=2,02, p=0,05). Enquanto nenhum caso de apinhamento e de sobremordida foi observado na aldeia Iriri, a razão da prevalência era 2,64 vezes maior para a mordida aberta anterior (p=0,003), 2,83 vezes (p<0,001) para a mordida cruzada anterior, 3,93 (p=0,03) para a sobressaliência aumentada, e de 4,71 (p=0,02) para a mordida cruzada posterior. Observou-se uma alta prevalência das perdas dentárias, sem diferença entre as aldeias (RP=1,46, p=0,11). O exame dos modelos revelou uma tendência de incisivos maiores e pré-molares e caninos menores na aldeia Iriri, delineando uma semelhança na massa dentária total entre as aldeias, que, aliada a arcadas dentárias maiores, justificaram o menor índice de irregularidade dos incisivos entre esses indígenas. Esses resultados minimizam a influência do desgaste dentário, uma evidência direta de como um indivíduo se alimentou no passado, no desenvolvimento dentofacial e enfatizam o predomínio da hereditariedade, através da endogamia, na etiologia da variação anormal da oclusão dentária e da morfologia da face.
The influence of diet and genetics on dentofacial features was examined through the analysis of two split indigenous Amazon populations originated by a process of a linear fission. The Arara-Iriri indigenous are descendants of a single couple who were expelled from a larger village (Arara-Laranjal). In the resultant new village, the initial expansion occurred through the mating of closely related people, causing a high coefficient of inbreeding (F=0.25, p<0.001). The epidemiology of malocclusion and facial characteristics were analyzed in individuals aged from 2 to 22 years, from the Arara-Iriri (n=46) and Arara-Laranjal (n=130) villages. The biometric study of the dentition and face was performed in the permanent dentition of the indigenous without tooth loss (n=55) by facial photogrammetry and dental casts analysis. Tooth wear was examined in 126 individuals in the permanent dentition through multiple regression analysis. Findings pointed out a significant determination of age on tooth wear (R2=87.6, p<0.0001), which was similar between the villages (R2=0.027, p=0.0935). However, we found marked differences in the dentofacial morphology. The indigenous of the Iriri village presented a more vertical face (dolichofacial) compared to the people of the original village, predominantly braquifacial. This clinical data was corroborated by facial photogrammetry. A sagitally normal face was observed in 97.7% of the Laranjal village, while convex (26.1%, RR=16.96) and concave faces (15.2%, RR=19.78) were significantly more prevalent in the Iriri village (p<0.001). Biprotrusion, with consequent reduction of nasolabial angle, was a common feature among the Arara indigenous, but its occurrence in the Iriri village was higher (RP=1.52, p=0.0002). The prevalence of malocclusion was significantly higher in the Iriri population (RP=1.75, p=0.0007). While the majority of the population (83.8%) in the Laranjal village presented a normal Class I relationship, in the Iriri village 34.6% were Class III (RP=6.01, p<0.001) and 21.7% were class II (RP=2.02, p=0.05). No case of crowding and overbite was observed in the Iriri village, however the relative risk was 2.64 times greater for anterior open bite (p=0.003), 2.83 for anterior crossbite (p<0.001), 3.93 for increased overjet (p=0.03), and 4.71 times (p=0.02) for posterior crossbite. We observed a high prevalence of tooth loss, with no significant difference between the villages (RP=1.46, p=0.11). The dental cast analysis revealed larger incisors combined to smaller cuspids and bicuspids in the Iriri sample, causing an overall similarity in the total tooth size between the villages, which associated to larger dental arch dimensions, explained a decreased incisor irregularity in the Iriri indigenous. These findings mitigates the influence of tooth wear, a direct evidence of what an individual ate in the past, on dentofacial development and emphasize the role of heredity, through inbreeding, in the etiology of abnormal variation of dental occlusion and facial morphology of current human populations.
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Teixeira, Ana Filipa dos Santos. "Lesões Cervicais Não Cariosas: revisão bibliográfica." Master's thesis, [s.n.], 2013. http://hdl.handle.net/10284/4452.
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina DentáriaAs Lesões Cervicais Não Cariosas caracterizam-se pela perda irreversível e gradual de tecido mineralizado junto da junção amelo-cementaria, sem qualquer envolvimento bacteriano. A etiologia é quase sempre multifatorial, constituindo assim o principal obstáculo ao trabalho do Médico Dentista na realização de um diagnóstico diferencial. Estas lesões dividem-se segundo a etiologia em erosão, abrasão, abfração. A erosão é a dissolução dos tecidos duros por ácidos de origem não bacteriana. A abrasão é o desgaste dos mesmos tecidos dentários por ações mecânicas externas, normalmente associadas a escovagens agressivas. E, por sua vez, a abfração é a perda de tecido dentário na região cervical devido à flexão dentária provocada por sobrecargas oclusais e movimentos excêntricos. A perda progressiva da estrutura dentária associada à ocorrência de Lesões Cervicais Não Cariosas tem-se mostrado cada vez mais frequente na prática clínica contemporânea, tendo em conta o aumento da expectativa de vida e a manutenção da dentição natural. Dessa forma, o número de pessoas que têm os dentes expostos por um maior período de tempo, aos vários fatores etiológicos relacionados à perda progressiva e não cariosa das estruturas dentárias, também tem aumentado, facto que pode resultar em complicações estéticas e funcionais. Estas lesões levam com frequência a quadros de hipersensibilidade dentinária existindo hoje em dia numerosas opções de agentes dessensibilizantes. O tratamento destas lesões preconiza a eliminação dos fatores etiológicos, caso contrário, todo o tratamento será condenado ao insucesso. Assim, o objetivo deste trabalho destina-se a realizar uma revisão de literatura acerca dos fatores etiológicos, classificação, características clínicas e opções terapêuticas para as Lesões Cervicais Não Cariosas, possibilitando aos médicos-dentistas o estabelecimento do diagnóstico diferencial, de condutas preventivas e de tratamento. Este trabalho faz também uma breve abordagem à hipersensibilidade dentinária, decorrente das LCNC, sua etiologia e opções de tratamento. Foi realizada uma pesquisa bibliográfica baseada em artigos científicos, revistas científicas e livros, cujo limite temporal recaiu entre 1994 e 2012 com as seguintes Palavras-Chave: erosão, abrasão, atrição, abfração, desgaste dentário, hipersensibilidade dentinária, Lesões Cervicais Não Cariosas, erosion, abrasion, attrition, abfraction, tooth wear, tooth sensitivity, non-carious cervical lesion. . O primeiro passo de qualquer plano de tratamento das Lesões Cervicais Não Cariosas está sem dúvida reservado à identificação e remoção dos agentes etiológicos que originaram as lesões; a não eliminação desses fatores causais vai inevitavelmente levar a uma recidiva das lesões, ao fracasso de qualquer procedimento restaurador e ao regresso de uma sintomatologia dolorosa previamente existente. O tratamento da hipersensibilidade dentinária também só será eficiente após identificação, remoção e redução dos fatores etiológicos. The carious cervical lesions are characterized by irreversible and progressive loss of mineralized tissue along the cementoenamel junction , without bacterial involvement. The etiology is often multifactorial , thus constituting a major obstacle to job Dentist in making a differential diagnosis. These lesions are divided into etiology according to erosion , abrasion, abfraction . Erosion is the dissolution of hard tissues by acid non-bacterial origin. Abrasion is wear the same dental tissues by external mechanical actions usually associated with aggressive brushing . And in turn , the abfraction is the loss of dental tissue in the neck due to bending caused by dental occlusal loads and eccentric movements . The progressive loss of tooth structure associated with the occurrence of carious cervical lesions has been shown to be increasingly common in contemporary clinical practice , taking into account the increase in life expectancy and the maintenance of the natural dentition . Thus , the number of people who have teeth exposed for a longer period of time , the various etiological factors related to progressive loss of dental caries and not structures , has also increased , which might result in aesthetic and functional complications . These injuries often lead to pictures of dentin hypersensitivity exist today numerous options desensitizing agents . Treatment of these lesions entails the elimination of etiological factors , otherwise , all treatment will be doomed to failure .
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Yamashita, Joselene Martinelli. "Estudo transversal sobre problemas bucais em pacientes obesos mórbidos." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/25/25144/tde-14082013-094157/.
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A prevalência da obesidade tem aumentado em proporções alarmantes, tornando-se um problema de saúde pública. Há relatos de uma possível relação da obesidade com a condição bucal e o objetivo do presente estudo foi identificar os problemas bucais e seu impacto na qualidade de vida de indivíduos obesos mórbidos. A amostra foi composta por 100 pacientes obesos mórbidos (grupo obeso) e 50 indivíduos eutróficos (grupo controle), atendidos no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da USP. Os pacientes responderam um questionário socioeconômico e outro de qualidade de vida, o Oral Impacts on Daily Performances (OIDP) e, em seguida, foi realizado o exame bucal. O índice International Caries Detection & Assessment System II (ICDAS II) foi utilizado para avaliar a cárie dentária; o Índice Periodontal Comunitário (IPC) e Perda de Inserção Periodontal (PIP) avaliaram as condições periodontais e o Índice de Desgaste Dentário (IDD) para avaliar a prevalência e severidade do desgaste. Ainda foram avaliados o fluxo salivar estimulado e o pH da saliva. Para análise estatística foram utilizados os testes T de Student, Qui-quadrado e Regressão Linear Múltipla. A média do OIDP foi de 13,06 ± 23,27 para o grupo obeso e 4,36 ± 10,92 para o grupo controle, indicando maior impacto da condição bucal no desempenho diário dos obesos (p=0,060). O grupo obeso apresentou maior prevalência e severidade de cárie (p=0,041) e de doença periodontal (p<0,050). Foi observada maior severidade de desgaste nos obesos (p<0,050). Ambos os grupos apresentaram fluxo salivar baixo, sendo significativamente menor entre os obesos (p=0,005). Após o ajuste da amostra, observou-se que as condições periodontais continuaram relacionadas à obesidade, enquanto que perda dentária, desgaste e fluxo salivar foram influenciados pela idade no grupo obeso e a cárie dentária pelo nível socioeconômico deste grupo. As condições de saúde bucal dos pacientes obesos mostraram-se piores em relação aos eutróficos, principalmente quanto à doença periodontal, o que contribuiu para um impacto negativo na qualidade de vida.The prevalence of obesity has increased in alarming proportions, becoming a public health problem. There are reports of a possible relationship between obesity and oral condition and the objective of this study was to identify oral problems and their impact in quality of life of morbidly obese individuals. The sample was composed of 100 morbidly obese patients (obese group) and 50 normal weight patients (control group) examined at the School of Medicine Hospital of Ribeirão Preto- USP. The subjects answered a socioeconomic and a quality of life questionnaire, the Oral Impacts on Daily Performances (OIDP) and, in the sequence the dental examination was performed. The International Caries Detection & Assessment System II (ICDAS II) was used to evaluate tooth decay, the Community Periodontal Index (CPI) and Clinical Attachment Level (CAL) evaluated periodontal conditions and the Dental Wear Index evaluated the prevalence and severity of wear. Also were evaluated the stimulated salivary flow and the Ph of saliva. Students t test, Chi- Square and Multiple Regression were used for statistical analysis. The average OIDP was 13.06 ± 23.27 for the obese group and 4.36 ± 10.92 for the control group, indicating higher impact of oral health in the quality of life of obese individuals (p=0.060). The obese group showed greater prevalence and severity of decay (p=0.041) and of periodontal disease (p< 0.050). Both groups showed low salivary flow and it was significantly lower among obese (p=0.005). After adjustment of the sample, it was observed that the periodontal conditions related to obesity continued, while that tooth loss, dental wear and salivary flow were influenced by age in obese group and the dental decay by the socioeconomic level of this group. The oral health condition of obese patients appeared worse when compared to eutrophic, mainly regarding periodontal disease, which contributed to a negative impact on quality of life.
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Sánchez, Hernández Carlos. "Paleoecología neandertal durante el Paleolítico medio en el norte y este de la Península Ibérica. Análisis combinado de desgaste dental y cementocronología." Doctoral thesis, Universitat Rovira i Virgili, 2020. http://hdl.handle.net/10803/671690.
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La correlació entre l'ecologia humana i les condicions ambientals en les que desenvolupaven les seves activitats de supervivència ha estat subjecte d'intens estudi en les últimes dècades. D'especial interès és el Plistocè superior, caracteritzat per fortes fluctuacions ambientals, especialment marcades durant el MIS 3 (60-30 ka BP). Durant aquest període, els grups neandertals que van habitar Europa es van caracteritzar per mostrar una elevada variabilitat comportamental. Això incita a preguntar-se fins a quin punt aquestes fluctuacions poden afectar la presa de decisions en l'elaboració de les seves estratègies de subsistència.
Atès que les característiques ambientals també poden variar en funció d’altres condicionants regionals (p.e. ubicació geogràfica), i fins i tot locals (p.e. orografia i altitud), la present investigació pretén contribuir a aquesta qüestió mitjançant la caracterització de la durada i l’estacionalitat de les ocupacions neandertals en dues regions bioclimàtiques clarament diferenciades de la Península Ibèrica: la cantàbrica (Covalejos) i la mediterrània (Arbreda, Teixoneres, Abric Romaní i El Salt). El principal objectiu consisteix en constatar el tipus de resposta d'aquests grups davant contextos ambientals diferenciats, al mateix temps que es posa a prova la resolubilitat de la integració metodològica de diversos proxis d'alta resolució.
La consecució dels objectius plantejats requereix de la reconstrucció de la dieta de les principals preses dels grups humans (i.e. cérvol, cavall, ase salvatge i ur), fet que permetrà conèixer la durada i el moment de l'any en què es va ocupar una cova. Aquests animals són sensibles als canvis ambientals dels seus hàbitats. Per això analitzem els seus molars i premolars a través del desgast dental (meso- i microdesgast) i la cementocronologia dental. El mesodesgast identifica la dieta anual, al mateix temps que reflecteix els canvis dietètics de les preses a llarg termini (mesos), que són conseqüència de canvis en l'hàbitat. D’altra banda, el microdesgast reflecteix la dieta en els instants previs a la mort de cada presa, permetent identificar el tipus de recursos que consumeix i generant una imatge molt precisa de les característiques puntuals de l'hàbitat. La cementocronologia en canvi, permet determinar l'estació de l'any en què els neandertalsLa correlación de la ecología humana y las condiciones ambientales en las que desarrollaban sus actividades de supervivencia ha sido sujeto de intenso estudio en las últimas décadas. De especial interés es el Pleistoceno superior, caracterizado por fuertes fluctuaciones ambientales, especialmente durante el MIS 3 (60-30 ka BP). Durante este periodo, los grupos neandertales que habitaron Europa se caracterizaron por mostrar una elevada variabilidad comportamental. Ello suscita la cuestión acerca de en qué grado dichas fluctuaciones pueden afectar la toma de decisiones en la elaboración de sus estrategias de subsistencia. Dado que las características ambientales también están sujetas a condicionantes regionales (e.g. ubicación geográfica), e incluso locales (e.g. orografía y altitud), la presente investigación pretende contribuir a esta cuestión mediante la caracterización de la duración y estacionalidad de las ocupaciones neandertales en dos regiones bioclimáticas claramente diferenciadas de la Península Ibérica: cantábrica (Covalejos) y mediterránea (Arbreda, Teixoneres, Abric Romaní y El Salt). El principal objetivo consiste en constatar el tipo de respuesta de estos grupos ante contextos ambientales diferenciados, al tiempo que se pone a prueba la resolutividad de la integración metodológica de varios proxis de alta resolución. La consecución de los objetivos planteados requiere de la reconstrucción de la dieta de las principales presas de los grupos humanos (i.e. ciervo, caballo, asno salvaje y uro), hecho que permitirá conocer la duración y el momento del año en el que ocupó una cueva. Estos animales son sensibles a los cambios ambientales de sus hábitats. Para ello, analizamos sus molares y premolares a través del desgaste dental (meso- y microdesgaste) y la cementocronología dental. El mesodesgaste identifica la dieta anual, al tiempo que refleja los cambios dietéticos de las presas a largo plazo (meses), que son consecuencia de cambios en el hábitat. El microdesgaste por otro lado, refleja la dieta en los instantes previos a la muerte de cada presa, permitiendo identificar el tipo de recursos que consume y generando una imagen muy precisa de las características puntuales del hábitat. La cementocronología a cambio, permite determinar la estación del año en el que los neandertales han abatido a sus p
The correlation of human ecology and the environmental conditions in which they developed their survival activities has been the subject of intense study in recent decades. Of special interest is the Late Pleistocene, characterized by strong environmental fluctuations, especially during MIS 3 (60-30 ka BP). During this period, the Neanderthal groups that inhabited Europe were characterized by showing a high behavioral variability. This raises the question about the extent to which these fluctuations can affect decision making in the development of their livelihood strategies. Since environmental characteristics are also subject to regional (e.g. geographic location), and even local (e.g. orography and altitude) conditions, the present research aims to contribute to this issue by characterizing the duration and seasonality of Neanderthal occupations in two bioclimatic regions clearly differentiated of the Iberian Peninsula: Cantabrian (Covalejos) and Mediterranean (Arbreda, Teixoneres, Abric Romaní and El Salt). The main objective is to verify the type of response of these groups to differentiated environmental contexts, while the resolution of the methodological integration of three high-resolution proxies is tested. The achievement of the proposed objectives requires the reconstruction of the diet of the main preys of the human groups (i.e. red deer, horse, wild ass and auroch). The dietary reconstruction would allow knowing the duration and the seasonality of the human occupations along the annual cycle since these animals are sensitive to the environmental changes of their habitats. Therefore, we analyze the ungulate molars and premolars through dental wear (meso- and micro-wear) and dental cementochronology. The mesowear identifies the annual diet, and reflects the dietary changes of the preys in a long-term scale (months as consequence of habitat changes. The microwear on the other hand, reflects the diet days before the death of each prey allowing identifying the type of resources they consumed and generating a very precise image of the specific characteristics of the habitat. The cementochronology in turn, allows determining the season of the year in which the Neanderthals have killed their prey, while placing in a temporal frame the dietary characteristics of both their preys, and their survival str
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Montero, Melisa Patricia Rodriguez. "Associação da má oclusão e bruxismo com qualidade de vida de adolescentes." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/25/25144/tde-11042015-111923/.
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A má oclusão e o bruxismo são problemas que podem interferir na qualidade de vida de adolescentes. Este estudo observacional transversal e analítico teve como objetivo investigar a associação entre má oclusão e bruxismo, com a qualidade de vida de adolescentes entre 12-15 anos de idade. A amostra foi selecionada por conglomerado e composta por 370 adolescentes de ambos os gêneros, estudantes da rede estadual de ensino de Bauru-SP. A má oclusão foi medida pelo Dental Aesthetics Index (DAI). Para o bruxismo foram avaliadas as facetas de desgastes dos dentes por meio do Índice de Desgaste Dentário (IDD). Foram aplicados dois questionários, um para o bruxismo e o outro para a qualidade de vida (OHIP-14). O Índice de Massa Corporal (IMC) foi calculado segundo normas da OMS. Teste Qui-quadrado, Correlação de Spearman, Mann-Whitney e Kruskall-Wallis foram aplicados (P<0,05). A má oclusão muito severa e o bruxismo foram mais prevalentes no gênero feminino, enquanto no masculino identificou-se a má oclusão definida. O bruxismo autorrelatado foi encontrado em 18,9% dos adolescentes. A maioria dos adolescentes apresentou peso normal. Bruxismo, apinhamento, mordida aberta, relação molar e desalinhamento maxilar estiveram relacionados à qualidade de vida (p<0,050). Bruxismo e alguns tipos de má oclusão interferem na qualidade de vida de adolescentes.Malocclusion and bruxism are problems that can interfere with the quality of life in adolescents. This cross-sectional analytical study aimed to identify the association between malocclusion, bruxism and quality of life in adolescents aged 12-15 years. The sample is composed of 370 adolescents, both genders, students from state schools in Bauru, SP. The malocclusion was measured by the Dental Aesthetic Index (DAI). For bruxism was evaluated the wear of teeths faces through the Tooth Wear Index (TWI). Two questionnaires, one for bruxism and one for quality of life (OHIP-14) were applied, in addition, BMI was calculated according to WHO standards. Chi-square, Spearman correlation, Mann-Whitney and Kruskal-Wallis test were applied (P<0.05). Very severe malocclusion and bruxism were more prevalent in females and defined malocclusion in males. Selft-related bruxism was found in 18.9% of adolescents. The majority of the adolescents had normal weight. Bruxism, crowding, open bite, molar relationship and maxillary misalignment were related to quality of life (P <0.05). Bruxism and some types of malocclusion interfere in the quality of life of adolescents.
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Romano, Juliana Jendiroba Faraoni. "Avaliação do desgaste superficial do esmalte e da dentina radicular submetidos ao tratamento clareador: in vitro e in situ." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/58/58133/tde-30082010-094935/.
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Devido a alterações químico-estruturais causadas pelo clareamento, os substratos dentais poderiam tornar-se mais susceptíveis a perda tecidual, principalmente se expostos a desafios erosivo/abrasivos. Desta forma, o presente estudo teve como objetivos: 1) analisar in vitro, se o esmalte e a radicular dentina clareada com diferentes agentes e concentrações, apresenta uma maior susceptibilidade ao desgaste, quando submetido a ciclos de erosão e abrasão; 2) comparar o efeito da aplicação de um agente clareador a base de peróxido de carbamida a 10% a um placebo no desgaste do esmalte e da dentina radicular, através de um modelo in situ. Os resultados do estudo in vitro mostraram que, independentemente do agente usado, o clareamento não aumentou o desgaste do esmalte frente a episódios erosivo-abrasivos. Na dentina, o desgaste foi dependente do agente clareador aplicado. Baseado no protocolo in situ adotado, o peróxido de carbamida a 10% não causou maior desgaste superficial no esmalte, mas aumentou a perda de tecido dentinário comparado ao placebo. Pode-se concluir que, em termos de desgaste superficial, o esmalte não foi afetado pelo tratamento clareador, enquanto a dentina mostrou-se mais susceptível. Assim, sugerem-se cuidados adicionais na seleção do agente clareador em situações clínicas que apresentam dentina radicular exposta.Due to the chemical and microstructural alterations caused by bleaching, the dental substrates can become more susceptible to tissue loss, mainly if exposed to erosive/abrasive challenges. Therefore, the present study had the following objectives: 1) to analyze in vitro, if enamel and root dentin that had been bleached with different agents and concentrations, were at increased risk of wear when submitted to cycles of erosion and abrasion; 2) to compare the effect of the application of a 10% carbamide peroxide bleaching agent to a placebo on wear of enamel and root dentin, through an in situ model. The results of the in vitro study showed that independent of agent used, the bleaching demonstrated no increase in the wear of enamel when exposed to the erosive-abrasive episodes. In dentin, the wear was dependent on the bleaching agent applied. Based on the in situ protocol adopted, the 10% carbamide peroxide did not cause higher wear on the enamel, but increased the wear of the root dentin compared to the placebo. It could be concluded that in terms of superficial wear, enamel was not affected by bleaching treatment, while dentin showed to be more susceptible. Thus, additional caution is suggested in the choice of the bleaching agent when root dentin is exposed.
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Xavier, Cheila Nilza Hamina. "Avaliação in situ do efeito do gel contendo euclea natalensis na superfície dentária, antes do desafio erosivo seguido ou não da abrasão." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/25/25144/tde-18012012-145230/.
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Este estudo avaliou in situ a ação do gel contendo euclea natalensis na redução da erosão associada ou não abrasão em esmalte e dentina humanos. O estudo foi realizado em duas fases cruzadas de cinco dias cada (SG - sem gel e CG - com gel) nas quais 10 voluntários utilizaram placas palatinas com 4 blocos de esmalte e 4 blocos de dentina, distribuídos em duas fileiras horizontais contendo 4 blocos, correspondendo aos subgrupos: erosão (Eros); erosão + abrasão (30min) (Eros + Abras). Em fases alternadas metade dos voluntários teve a aplicação do gel em todos espécimes do aparelho e na outra metade os espécimes não sofreram tratamento nenhum. O gel foi aplicado durante 5 minutos, sendo o mesmo removido após este tempo. Na etapa experimental os aparelhos foram imersos em refrigerante 4x ao dia, por 5 minutos. A seguir o aparelho foi colocado na boca por 30 minutos. Após este período os voluntários escovaram 4 espécimes da fileira Eros + Abras e recolocaram o aparelho. A outra fileira (Eros) não foi escovada. A análise da perda de estrutura dentária foi realizada por meio de teste de perfilometria e microdureza. Foi utilizada a análise de variância (ANOVA) a 2 critérios (presença ou ausência da aplicação do gel) de acordo com cada substrato e o teste TUCKEY (p<0,05). Não houve associação entre perda de dureza e condições ou grupos testados (p>0,05). O desgaste dentário médio nos blocos de esmalte para o grupo CG foi de 12,86µm eros e 12,13µm eros+abras e para os blocos de dentina foi de 5,95µm eros e 6,16µm eros+abras. A média de desgaste dentário para o grupo SG, em blocos de esmalte foi de 14,08µm eros e 16,29µm eros+abras e, nos blocos de dentina foi de 13,64µm eros e 12,63µm eros+abras. Houve diferença significativa entre os grupos (p<0,05). Concluiu-se que o gel contendo euclea natalensis é capaz de reduzir o desgaste associado ou não a abrasão, independente do tipo de substrato, esmalte ou dentina.This study investigated the action of in situ gel containing euclea natalensis on reducing erosion associated or not with abrasion in the human enamel and dentin. The study was performed into two phases crossed in five days each (WOG-without gel and WG- with gel) in which ten volunteers used acrylic palatal appliances with four blocks of enamel and four dentin, distributed in two horizontal rows containing four blocks, corresponding to the subgroups: erosion (Eros); erosion + abrasion (30min) (Eros + Abras). In alternating phases half the volunteers had the applying the gel at all specimens. And the other half of the volunteers have not suffered any treatment. The gel was applied during 5 minutes, being removed after this time. In stage experimental, the blocks were subjected to erosion by immersion of the appliances into soft drink for five minutes, 4 times a day. The appliance was then replaced into the mouth for 30 minutes. After this period the volunteers brushed row (eros+abrasion) and replaced into the mouth. The row (eros) was not brushed. The analysis of the dental structure were determined using profilometry and microhardness tests. ANOVA by two criteria (presence or absence of application of gel) in agreement with each the substrate and Tukey test were applied (p <0.05). Microhardness and conditions or groups tested were not found association (p> 0.05). The mean wear in enamel blocks was 12.86µm eros and 12.13µm eros + abras in the WG group and in dentin blocks was 5.95 µm eros and 6.16µm eros+ abras. The mean wear in enamel blocks was 14.08µm eros and 16.29µm eros+abras for the WOG group and in dentin blocks was 13.64µm eros and 12.63µm eros + abras. There was significant difference between groups (p <0.05). It concluded that the gel containing Euclea Natalensis can reduce erosion with or without abrasion, independently of the substrate type, enamel or dentin.
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Aguiar, Livia Maria Dante. "Estudo in vivo da etiologia das lesões cervicais não cariosas." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/23/23134/tde-14012013-124821/.
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As lesões cervicais não cariosas (LCNCs) são caracterizadas pela perda de estrutura dental no terço cervical dos dentes, que se origina a partir de mecanismos não relacionados com o processo de cárie. Este trabalho buscou investigar a correlação das LCNCs (severidade e acometimento), com os seguintes fatores: idade, sexo, dieta, hábitos parafuncionais, hábitos de higiene dental, distúrbios gástricos e aspectos oclusais. Foram estudados cinquenta pacientes (36 mulheres e 14 homens), com idades entre 20 e 62 anos (média de 40.9 anos). A avaliação consistiu na aplicação de questionários e exame clínico intraoral. Um índice de desgaste dental foi utilizado para classificação da severidade das LCNCs e do desgaste da borda incisal/face oclusal. Os resultados mostraram que os primeiros pré-molares (20,5%), segundos pré-molares (19,5%), caninos (14%), primeiros molares (13,9%) e segundos molares (11,6%) foram os dentes mais acometidos pelas LCNCs. Foi constatada correlação positiva entre idade e o percentual de dentes acometidos, ou seja, quanto maior a idade do paciente, maior foi o percentual de dentes acometidos com LCNC (p=0,003). Foi constatado que os pacientes com ingestão diária de alimentos e bebidas ácidas apresentaram relação significante com a severidade das LCNCs (p=0,038) e também apresentaram maior percentual de dentes acometidos pelas LCNCs (p=0,014). Não foi verificada relação significante entre as LCNCs (severidade e percentual de dentes acometidos) com o sexo dos pacientes, número de escovações diárias, apertamento dental, bruxismo, distúrbios gástricos, força durante a escovação e tipo de cerdas da escova. Quanto aos aspectos relacionados à oclusão, foi observada pequena correlação (r=0,079) entre o desgaste cervical e o desgaste da borda incisal/face oclusal. Em nenhum caso foi observada diferença estatística significante da severidade das LCNCs entre dentes que participam ou não do movimento de lateralidade.Noncarious cervical lesions (NCCL) are characterized by loss of tooth structure in the cervical area, and originated by mechanisms unrelated to dental caries process. This study investigated the correlation of NCCL (severity and involvement) with the following factors: age, gender, diet, parafunctional habits, dental hygiene, gastric disorders and occlusal aspects. Fifty patients (36 female and 14 male) aged between 20 and 62 years (mean age of 40.9 years) were evaluated. The evaluation consisted of questionnaires and intraoral clinical examination. A Tooth Wear Index was used to classify the severity of NCCL and wear of the incisal/ occlusal surface. Results indicate that first premolars (20,5%), second premolars (19,5%), canine (14%), first molars (13,9%) and second molars (11,6%) were the teeth most affected by NCCL. There was correlation between the age of patients and the percentage of teeth affected, meaning that the older the patient, the higher the percentage of teeth affected with NCCL (p=0,003). Patients with daily intake of acidic foods and beverages presented a significant relationship with the severity of NCCL (p=0,038) and also a higher percentage of teeth affected by NCCL (p=0,014). There was no significant relationship between NCCL (severity and percentage of affected teeth) and gender of patients, number of daily brushings, teeth clenching, bruxism, gastric disorders, force applied during toothbrushing and characteristics of the toothbrushes. There was a small correlation (r=0,079) between NCCL and the wear of incisal/occlusal surface. Regarding the severity of NCCL, no significant statistical differences were observed between the teeth involved or not in the lateral excursive movement.
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Sehovic, Amela, and Mona Saado. "Erosionsskador hos barn och ungdomar." Thesis, Högskolan Kristianstad, Sektionen för Hälsa och Samhälle, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-8430.
Full textAbstract:
Aim: The aim of this study was to examine and explain the various methods available to rate the erosion damage, and on which teeth and tooth surfaces of erosion damage mostly occurs in children and adolescents. Method: A literature review was conducted, based on 15 scientific articles that have been reviewed, evaluated and analyzed. Articles were searched for in the database PubMed. Result: Six of the articles used the TWI (tooth wear index), which is an index to diagnose the tooth wear in the primary and permanent dentition. Eight articles used other indices as they considered that the TWI was not sufficiently developed to register the degree of tooth wear on some teeth. Tooth wear in the primary dentition occurs most often in the canines and incisors. Tooth wear in the permanent dentition was found in the literature to be mostly occurring on the occlusal / incisal surfaces of all teeth and tooth surfaces.Lyssna Conclusion: There is no common index in the articles but many of them use the TWI. It may therefore be beneficial for the future to development a common index that can be useful for all age groups and categories in order to diagnose the tooth wear.
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Souza, Samira Helena João de. "Efeito de tratamentos dessensibilizantes e/ou anti-erosivos na permeabilidade e perda de superfície da dentina." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/23/23134/tde-15082018-104812/.
Full textAbstract:
Esta tese de Doutorado apresenta três estudos in vitro independentes. Na parte 1, avaliou-se a permeabilidade dentinária após tratamentos dessensibilizantes de consultório e a resistência destes à ciclagem erosiva-abrasiva de 5 dias; na parte 2, avaliou-se a permeabilidade dentinária após aplicação de cremes dentais dessensibilizantes e/ou anti-erosivos durante uma ciclagem erosiva-abrasiva de 5 dias; e na parte 3, avaliou-se a perda de superfície dentinária resultante da utilização dos cremes dentais dessensibilizantes e/ou anti-erosivos em um modelo de ciclagem erosiva-abrasiva inicial. Nas partes 1 e 2 os túbulos dentinários dos espécimes de dentina foram abertos com solução de EDTA e a permeabilidade máxima inicial foi analisada (considerada 100%). Na parte 1, os tratamentos dessensibilizantes de consultório foram realizados e a permeabilidade dentinária reavaliada (%Lp-após tratamento). Em ambos estudos, os espécimes passaram por uma ciclagem erosivaabrasiva de 5 dias. Cada dia consistiu em 4 imersões em ácido cítrico (2 min, 1%, pH ~2,6), com exposição à saliva humana clarificada por 60 min entre os desafios erosivos. Trinta minutos após o primeiro e último desafios erosivos, os espécimes foram escovados em máquina de escovação (2 N, 45 ciclos) totalizando 2 minutos de exposição às suspensões formadas por creme dental e saliva humana. Na parte 1, foi utilizado um creme dental fluoretado convencional para todos os grupos e na parte 2, cremes dentais de acordo com cada grupo. Ao final dos 5 dias de ciclagem, a permeabilidade dentinária final (%Lp-após ciclagem) foi avaliada. Os mesmos cremes dentais testados na parte 2 também foram testados quanto à perda de superfície (PS) na parte 3. Para isso, os espécimes tiveram duas partes das superfícies protegidas com uma fita adesiva de forma a deixar uma área central exposta e, então, foram submetidos a 5 ciclos de erosão-abrasão iniciais. Em cada ciclo os espécimes foram imersos em saliva artificial (60 minutos; pH 7), e em ácido cítrico (3 minutos; 1%; pH 3,6). Então, os espécimes foram escovados em máquina de escovação (2 N; 25 ciclos) com as suspensões formadas pela mistura dos cremes dentais com saliva artificial, totalizando 2 minutos de exposição às suspensões. Para cada estudo, os dados de %Lp e PS foram estatisticamente analisados. Parte 1: Os grupos NUPRO e Gluma Desensitizer foram os únicos que apresentaram menor %Lp quando comparados com controle negativo (p=0,026 e p=0,022; respectivamente), em ambos os tempos analisados. Parte 2: Os cremes dentais Regenerate e Sensodyne Pronamel apresentaram menor %Lp em comparação com o grupo controle negativo (p<0,05). Parte 3: Os grupos apresentaram diferentes graus de PS independente da indicação comercial, sendo o Elmex Erosion Protection, o único grupo com baixa PS que se diferenciou do controle positivo (p=0,031). Pode-se concluir que os tratamentos de consultório NUPRO e Gluma Desensitizer e os cremes dentais Regenerate e Sensodyne Pronamel foram os melhores em diminuir a %Lp, no modelo estudado. Em relação à PS, em um modelo de ciclagem erosiva-abrasiva inicial, os cremes dentais apresentaram diferentes graus de PS, independente da indicação comercial, tendo o Elmex Erosion Protection mostrado o resultado mais promissor.This PhD thesis presents three independent in vitro studies. At part 1, dentine permeability was evaluated after in-office desensitizing treatments and their resistance to an erosive-abrasive cycling of 5 days; at part 2, dentine permeability was evaluated after application of desensitizing and/or anti-erosive toothpastes during an erosive-abrasive cycling of 5-day; and at part 3, dentine surface loss resulting from the use of desensitizing and/or anti-erosive toothpastes in an initial erosive-abrasive cycling model was evaluated. At parts 1 and 2 the dentinal tubules were opened with EDTA solution and the initial maximum permeability was analyzed (considered 100%). At part 1, the in-office desensitizing treatments were performed and the dentine permeability was reevaluated (%Lp-after treatment). In both studies, the specimens underwent a 5-day erosive-abrasive cycling. Each day consisted of 4 immersions in citric acid (2 minutes, 1%, pH ~ 2.6), and exposure to clarified human saliva for 60 minutes between the erosive challenges. Thirty minutes after the first and the last erosive challenge, the specimens were brushed in a brushing machine (2 N, 45 cycles) totalizing 2 minutes of exposure to the slurries formed by the mixture of toothpaste and human saliva. At part 1, a regular fluoride toothpaste was used for all groups and at part 2, the toothpastes were used according to each group. After the 5 days of cycling, the final dentine permeability (%Lp-after cycling) was evaluated. The same toothpastes tested at part 2 were also analyzed for surface loss (SL) at part 3. For this, the specimens had two parts of the surfaces protected with an adhesive tape leaving a central area exposed, and then were submitted to 5 cycles of initial erosion-abrasion. In each cycle, the specimens were immersed in artificial saliva (60 minutes, pH 7) and in citric acid (3 minutes, 1%, pH 3.6). Then, the specimens were brushed in a brushing machine (2 N, 25 cycles) with the slurries formed by the mixture of the toothpastes with artificial saliva, also totalizing 2 minutes of exposure to the slurries. For each study, the data of %Lp and SL were statistically analyzed. Part 1: The groups NUPRO and Gluma Desensitizer were the only ones that presented lower %Lp when compared to the negative control (p=0.026 and p=0.022, respectively), at both periods analyzed. Part 2: Regenerate and Sensodyne Pronamel toothpastes presented lower %Lp compared to the negative control group (p<0.05). Part 3: The groups showed different degrees of SL regardless of the claim of the toothpaste. Elmex Erosion Protection was the only group with low SL that differed from the positive control (p=0.031). It can be concluded that the in-office treatments NUPRO and Gluma Desensitizer, and the toothpastes Regenerate and Sensodyne Pronamel were able to significantly reduce the %Lp, in the model studied. Considering the SL, analyzed with an initial erosive-abrasive cycling model, toothpastes presented different degrees of SL, regardless of their claim, and Elmex Erosion Protection showed the most promising results.
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Cavero, Garcia Aracelli Paola, and Draxl Mateo Gutierrez. "Asociación de la presencia de alteraciones morfológicas condilares de la articulación temporomandibular con los grados de facetas de desgaste dentario evaluados en tomografías." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2021. http://hdl.handle.net/10757/655432.
Full textAbstract:
Objetivo: Evaluar la asociación de la presencia de alteraciones morfológicas condilares de la articulación temporomandibular con los grados de facetas de desgaste dentario evaluados en tomografías.
Materiales y métodos: Un total de 208 tomografías fueron analizadas en este estudio. Se evaluaron las alteraciones morfológicas condilares (osteofito, aplanamiento, erosión, esclerosis, pseudoquiste), así como los grados de facetas de desgaste dentario del 0 al 4 según Hansson y Nilner. Además, se identificaron otras variables como la presencia de mordida abierta, overjet aumentado, overbite aumentado, entre otros. Se utilizó la prueba de Test Exacto de Fisher para evaluar la asociación de las variables y, para el cálculo de las razones de prevalencia crudas y ajustadas se utilizó la regresión de Poisson con varianza robusta.
Resultados: No se encontró asociación entre los grados de faceta de desgaste dentario y la presencia de alteraciones morfológicas condilares. Sin embargo, se observó que a mayor grado de faceta de desgaste hay un incremento en la prevalencia de alteraciones morfológicas. Así, aquellos con Grado 3 de desgaste poseían 36% más probabilidad de presentar alteraciones morfológicas condilares que aquellos con faceta de desgaste Grado 0 (p=0.004).
Conclusiones: Se observó que la presencia de alteraciones morfológicas condilares está relacionada al Grado 3 de desgaste dentario y al sexo femenino. Sin embargo, se sugiere enfocar nuevas investigaciones en la evaluación de Grados 2, 3 y 4 para corroborar lo encontrado.Objective: The aim of the study was to determine association between the presence of mandibular condyle osseous changes and tooth wear facets evaluated in cone beam computed tomography. Materials and methods: A total of 208 tomography were analyzed. Mandibular condyle osseous changes (osteophyte, flattening, erosion, sclerosis, pseudocyst) were evaluated and tooth wear was assessed between grades 0 to 4 according to Hansson & Nilner, Other variables such as the presence of open bite, increased overjet, increased overbite, among others, were identified. Fisher’s Exact test was used to evaluate association between variables. The crude and adjusted prevalence ratios were performed using the Poisson regression with robust variance. Results: No association was found between tooth wear and presence of mandibular condyle osseous changes. However, these increased as more dental structures got compromised. Thus, individuals with Grade 3 wear were 36% more likely to have mandibular condyle osseous changes than those with Grade 0 wear facet (p = 0.004). Conclusions: Presence of condylar osseous changes of the temporomandibular joint was associated with Grade 3 wear facet and gender. However, further examination of moderate to severe tooth wear is recommended to support the established association.
Tesis