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Journal articles on the topic 'Dental enamal'
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1
Sperber, Geoffrey H. "Dental enamel." South African Dental Journal 75, no. 7 (August 31, 2020): 384–86. http://dx.doi.org/10.17159/2519-0105/2020/v75no7a6.
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Dental enamel is the sparsest but most enduring component of all the tissues in the human body, yet contrarily contains the most detailed historiography of its development. Accordingly, analysis of enamels' chemistry, histology and pathology can reveal detailed ambient information of both fossilized, long-deceased and its contemporary milieu occurring during amelogenesis. In this respect, dental enamel is the most versatile exponent of its developmental mechanisms and acquisition of its complex form. Dental enamel is the ultimate lexicographer of lives lived.
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Daryakenari, G., H. Alaghehmand, and A. Bijani. "Effect of Simulated Mastication on the Surface Roughness and Wear of Machinable Ceramics and Opposing Dental Enamel." Operative Dentistry 44, no. 1 (January 1, 2019): 88–95. http://dx.doi.org/10.2341/17-153-l.
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SUMMARY Objective: Computer aided design-computer aided machining (CAD-CAM) ceramic crowns are replacing ceramo-metal ones due to newly developed mechanical properties and esthetics. To obtain knowledge about their interactions due to polishing and occlusal contacts with the opposing dental enamel specimen, including surface roughness and wear, the three-body wear simulation was investigated. Methods and Materials: The surface roughness (RA) and wear rate (mm) of four CAD-CAM blocks with different compositions including Vita Mark II, e.max, Suprinity, and Enamic, after two surface treatments of glazing and polishing, and their opposing enamel specimens, were investigated using a mastication simulator and atomic force microscope. Results: The roughness of all ceramic and to a greater extent enamel samples, with the exception of enamel opposing polished Enamic samples, was decreased after wear. No significant difference in wear was evident for the ceramic samples between the glazed and polished treatments. Lower wear rates were recorded only for polished Vita Mark II and polished Enamic in comparison to the glazed ones. Conclusion: The newly developed polishing systems for CAD-CAM ceramics can be good alternatives to reglazing, because the roughness and wear rate of both the ceramic and the opposing enamel will either not change or decrease.
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Robinson, P. A. "Dental enamel." Biochemical Education 26, no. 3 (July 1998): 258. http://dx.doi.org/10.1016/s0307-4412(98)00087-9.
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Bartlett, J. D., and J. P. Simmer. "Proteinases in Developing Dental Enamel." Critical Reviews in Oral Biology & Medicine 10, no. 4 (July 1999): 425–41. http://dx.doi.org/10.1177/10454411990100040101.
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For almost three decades, proteinases have been known to reside within developing dental enamel. However, identification and characterization of these proteinases have been slow and difficult, because they are present in very small quantities and they are difficult to purify directly from the mineralizing enamel. Enamel matrix proteins such as amelogenin, ameloblastin, and enamelin are cleaved by proteinases soon after they are secreted, and their cleavage products accumulate in the deeper, more mature enamel layers, while the full-length proteins are observed only at the surface. These results suggest that proteinases are necessary for "activating" enamel proteins so the parent proteins and their cleavage products may perform different functions. A novel matrix metalloproteinase named enamelysin (MMP-20) was recently cloned from tooth tissues and was later shown to localize primarily within the most recently formed enamel. Furthermore, recombinant porcine enamelysin was demonstrated to cleave recombinant porcine amelogenin at virtually all of the sites that have previously been described in vivo. Therefore, enamelysin is at least one enzyme that may be important during early enamel development. As enamel development progresses to the later stages, a profound decrease in the enamel protein content is observed. Proteinases have traditionally been assumed to degrade the organic matrix prior to its removal from the enamel. Recently, a novel serine proteinase named enamel matrix serine proteinase-1 (EMSP1) was cloned from enamel organ epithelia. EMSP1 localizes primarily to the early maturation stage enamel and may, therefore, be involved in the degradation of proteins prior to their removal from the maturing enamel. Other, as yet unidentified, proteinases and proteinase inhibitors are almost certainly present within the forming enamel and await discovery.
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Katta, Prashanth Kumar. "Enamel and Dentin Adhesion Differences." Indian Journal of Dental Education 10, no. 3 (2017): 170–72. http://dx.doi.org/10.21088/ijde.0974.6099.10317.3.
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Vieira, Alexandre R., Carolyn W. Gibson, Kathleen Deeley, Hui Xue, and Yong Li. "Weaker Dental Enamel Explains Dental Decay." PLOS ONE 10, no. 4 (April 17, 2015): e0124236. http://dx.doi.org/10.1371/journal.pone.0124236.
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Fejerskov, O., M. J. Larsen, A. Richards, and V. Baelum. "Dental Tissue Effects of Fluoride." Advances in Dental Research 8, no. 1 (June 1994): 15–31. http://dx.doi.org/10.1177/08959374940080010601.
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It is now well-established that a linear relationship exists between fluoride dose and enamel fluorosis in human populations. With increasing severity, the subsurface enamel all along the tooth becomes increasingly porous (hypomineralized), and the lesion extends toward the inner enamel. In dentin, hypomineralization results in an enhancement of the incremental lines. After eruption, the more severe forms are subject to extensive mechanical breakdown of the surface. The continuum of fluoride-induced changes can best be classified by the TF index, which reflects, on an ordinal scale, the histopathological features and increases in enamel fluoride concentrations. Human and animal studies have shown that it is possible to develop dental fluorosis by exposure during enamel maturation alone. It is less apparent whether an effect of fluoride on the stage of enamel matrix secretion, alone, is able to produce changes in enamel similar to those described as dental fluorosis in man. The clinical concept of post-eruptive maturation of erupting sound human enamel, resulting in fluoride uptake, most likely reflects subclinical caries. Incorporation of fluoride into enamel is principally possible only as a result of concomitant enamel dissolution (caries lesion development). At higher fluoride concentrations, calcium-fluoride-like material may form, although the formation, identification, and dissolution of this compound are far from resolved. It is concluded that dental fluorosis is a sensitive way of recording past fluoride exposure because, so far, no other agent or condition in man is known to create changes within the dentition similar to those induced by fluoride. Since the predominant cariostatic effect of fluoride is not due to its uptake by the enamel during tooth development, it is possible to obtain extensive caries reductions without a concomitant risk of dental fluorosis.
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Lang, J., S. Birkenbeil, S. Bock, R. Heinrich-Weltzien, and K. Kromeyer-Hauschild. "Dental enamel defects in German medieval and early-modern-age populations." Anthropologischer Anzeiger 73, no. 4 (November 1, 2016): 343–54. http://dx.doi.org/10.1127/anthranz/2016/0617.
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Tri, Nguyen Van. "Aperiodic crystal structure and conductivity of dental enamels and special porcelain enamel." Ferroelectrics 250, no. 1 (February 2001): 385–88. http://dx.doi.org/10.1080/00150190108225107.
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Simmer, J. P., and A. G. Fincham. "Molecular Mechanisms of Dental Enamel Formation." Critical Reviews in Oral Biology & Medicine 6, no. 2 (April 1995): 84–108. http://dx.doi.org/10.1177/10454411950060020701.
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Tooth enamel is a unique mineralized tissue in that it is acellular, is more highly mineralized, and is comprised of individual crystallites that are larger and more oriented than other mineralized tissues. Dental enamel forms by matrix- mediated biomineralization. Enamel crystallites precipitate from a supersaturated solution within a well-delineated biological compartment. Mature enamel crystallites are comprised of non-stoichiometric carbonated calcium hydroxyapatite. The earliest crystallites appear suddenly at the dentino-enamel junction (DEJ) as rapidly growing thin ribbons. The shape and growth patterns of these crystallites can be interpreted as evidence for a precursor phase of octacalcium phosphate (OCP). An OCP crystal displays on its (100) face a surface that may act as a template for hydroxyapatite (OHAp) precipitation. Octacalcium phosphate is less stable than hydroxyapatite and can hydrolyze to OHAp. During this process, one unit cell of octacalcium phosphate is converted into two unit cells of hydroxyapatite. During the precipitation of the mineral phase, the degree of saturation of the enamel fluid is regulated. Proteins in the enamel matrix may buffer calcium and hydrogen ion concentrations as a strategy to preclude the precipitation of competing calcium phosphate solid phases. Tuftelin is an acidic enamel protein that concentrates at the DEJ and may participate in the nucleation of enamel crystals. Other enamel proteins may regulate crystal habit by binding to specific faces of the mineral and inhibiting growth. Structural analyses of recombinant amelogenin are consistent with a functional role in establishing and maintaining the spacing between enamel crystallites.
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Murillo DDS, MSc, Gina, Carla Cob DDS, Natalia Mena DDS, Angie Valverde DDS, Belén Barrantes DDS, Ana Berrocal DDS, OMR, and Sandra Silva MQC, MSc. "Use of Dental Volumetric Tomography for Dental Phenotyping In Amelogenesis Imperfecta." Odovtos - International Journal of Dental Sciences 18, no. 1 (March 17, 2016): 83. http://dx.doi.org/10.15517/ijds.v18i1.23488.
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Amelogenesis imperfecta (AI) describes often severe, largely Mendelian biomineralisation defects of tooth enamel. AI enamel can be abnormally thin, soft, fragile, pitted and/or badly discoloured, resulting in major morbidity as patients have difficulty maintaining oral hygiene, experience low self-esteem due to poor aesthetics and report an inferior quality-of-life. Improved understanding of biomineralisation defects in AI would assist in clinical management of AI patients. Dental Volumetric Tomography (DVT, commonly known as Cone Beam CT scanning) is a diagnostic X ray based methodology that produces three -dimensional anatomical images of the skeletal tissues (including the teeth). The aim of this study was to investigate the use of DVT to provide detailed dental anatomy associated with AI. A Morita Veraviewpocs 3D R 100 was used to generate high definition 3D digital images of the maxillae of eight AI-affected volunteers (ethics approval N 440–B2-334 U.C.R.). Pulpal calcifications of varying size, Dens in Vaginitus, dental cysts, root fractures, retained teeth and anomalies in the position of the mandibular canal were all common findings. The data also revealed enamel surface irregularities in an unerupted tooth. In conclusion, use of DVT in AI would facilitate phenotyping by providing identification of dental/oral defects with greater accuracy and definition compared with conventional panoramic radiographs. The data could also be used to aid diagnostics, e.g. by permitting discrimination between hypoplastic enamel (diminished enamel volume) and hypomineralized enamel (failure of normal biomineralization). However, given the high costs associated with DVT and the radiation risks for individual patients, it is best indicated as a research tool for academic and clinical research proposes.
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Houari, S., E. Picard, T. Wurtz, E. Vennat, N. Roubier, T. D. Wu, J. L. Guerquin-Kern, et al. "Disrupted Iron Storage in Dental Fluorosis." Journal of Dental Research 98, no. 9 (July 22, 2019): 994–1001. http://dx.doi.org/10.1177/0022034519855650.
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Enamel formation and quality are dependent on environmental conditions, including exposure to fluoride, which is a widespread natural element. Fluoride is routinely used to prevent caries. However, when absorbed in excess, fluoride may also lead to altered enamel structural properties associated with enamel gene expression modulations. As iron plays a determinant role in enamel quality, the aim of our study was to evaluate the iron metabolism in dental epithelial cells and forming enamel of mice exposed to fluoride, as well as its putative relation with enamel mechanical properties. Iron storage was investigated in dental epithelial cells with Perl’s blue staining and secondary ion mass spectrometry imaging. Iron was mainly stored by maturation-stage ameloblasts involved in terminal enamel mineralization. Iron storage was drastically reduced by fluoride. Among the proteins involved in iron metabolism, ferritin heavy chain (Fth), in charge of iron storage, appeared as the preferential target of fluoride according to quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry analyses. Fluorotic enamel presented a decreased quantity of iron oxides attested by electron spin resonance technique, altered mechanical properties measured by nanoindentation, and ultrastructural defects analyzed by scanning electron microscopy and energy dispersive x-ray spectroscopy. The in vivo functional role of Fth was illustrated with Fth+/-mice, which incorporated less iron into their dental epithelium and exhibited poor enamel quality. These data demonstrate that exposure to excessive fluoride decreases ameloblast iron storage, which contributes to the defective structural and mechanical properties in rodent fluorotic enamel. They raise the question of fluoride’s effects on iron storage in other cells and organs that may contribute to its effects on population health.
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Cutress, T. W., C. H. Sissons, E. I. F. Pearce, L. Wong, K. Anderssén, and B. Angmar-Månsson. "Effects of Fluoride-Supplemented Sucrose on Experimental Dental Caries and Dental Plaque PH." Advances in Dental Research 9, no. 1 (February 1995): 14–20. http://dx.doi.org/10.1177/08959374950090010101.
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Sucrose, 5% and 10% (w/v), supplemented with between 0 and 5 ppm fluoride (F), was tested for its influence in vitro on plaque-induced experimental in vitro enamel caries and plaque pH. Plaque growth on bovine enamel was initiated from saliva inocula and sustained in a multiple plaque growth system for up to 31 days by means of a basal medium with periodic applications of sucrose or sucrose supplemented with F. Change in enamel mineralization was assessed, before and after plaque growth, by microhardness testing and microradiography; pH was monitored with microelectrodes. It was found that enamel demineralization was inversely related to the F concentration in the range 2 to 5 ppm, for both 5% and 10% sucrose. Plaque pH responses were unaffected by the F supplements.
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Tihaček-Šojić, Ljiljana, Vladimir Milićević, and Marija Đurić-Srejić. "Crystallographic and Colorimetric Analysis of Dental Enamel." Dental Anthropology Journal 11, no. 2 (September 7, 2018): 5–11. http://dx.doi.org/10.26575/daj.v11i2.213.
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Tooth color and the correlation of the compostion of dental enamel with color were investigated in samples of teeth from two medieval Serb cemeteries. Differences in the composition of apatite crystals in the dental enamel of the two samples were found. Color ranges of teeth from the two samples differ in hues and chromas. This result suggests that enamel composition may have an influence on the color of teeth. The prevalence of chlorapatite in enamel causes tooth color to be closer to red and of higher chroma than teeth whose enamel consists of hydroxylapatite. No evidenc indicated that soil ingredients were incorporated into the dental enamel of either sample.
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Hubbard, Michael J. "Calcium Transport Across the Dental Enamel Epithelium." Critical Reviews in Oral Biology & Medicine 11, no. 4 (October 2000): 437–66. http://dx.doi.org/10.1177/10454411000110040401.
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Dental enamel is the most highly calcified tissue in mammals, and its formation is an issue of fundamental biomedical importance. The enamel-forming cells must somehow supply calcium in bulk yet avoid the cytotoxic effects of excess calcium. Disrupted calcium transport could contribute to a variety of developmental defects in enamel, and the underlying cellular machinery is a potential target for drugs to improve enamel quality. The mechanisms used to transport calcium remain unclear despite much progress in our understanding of enamel formation. Here, current knowledge of how enamel cells handle calcium is reviewed in the context of findings from other epithelial calcium-transport systems. In the past, most attention has focused on approaches to boost the poor diffusion of calcium in cytosol. Recent biochemical findings led to an alternative proposal that calcium is routed through high-capacity stores associated with the endoplasmic reticulum. Research areas needing further attention and a working model are also discussed. Calcium-handling mechanisms in enamel cells are more generally relevant to the understanding of epithelial calcium transport, biomineralization, and calcium toxicity avoidance.
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Kaiser, Thomas M., Caroline Braune, Gerhard Kalinka, and Ellen Schulz-Kornas. "Nano-indentation of native phytoliths and dental tissues: implications for herbivore-plant combat and dental wear proxies." Evolutionary Systematics 2, no. 1 (June 4, 2018): 55–63. http://dx.doi.org/10.3897/evolsyst.2.22678.
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Tooth wear induced by abrasive particles is a key process affecting dental function and life expectancy in mammals. Abrasive particles may be plant endogenous opal phytoliths, exogene wind-blown quartz dust or rain borne mineral particles ingested by mammals. Nano-indentation hardness of abrasive particles and dental tissues is a significant yet not fully established parameter of this tribological system. We provide consistent nano-indentation hardness data for some of the major antagonists in the dental tribosystem (tooth enamel, tooth dentine and opaline phytoliths from silica controlled cultivation). All indentation data were gathered from native tissues under stable and controlled conditions and thus maximize comparability to natural systems. Here we show that native (hydrated) wild boar enamel exceeds any hardness measures known for dry herbivore tooth enamel by at least 3 GPa. The native tooth enamel is not necessarily softer then environmental quartz grit, although there is little overlap. The native hardness of the tooth enamel exceeds that of any silica phytolith hardness recently published. Further, we find that native reed phytoliths equal native suine dentine in hardness, but does not exceed native suine enamel. We also find that native suine enamel is significantly harder than dry enamel and dry phytoliths are harder than native phytoliths. Our data challenge the claim that the culprit of tooth wear may be the food we chew, but suggest instead that wear may relates more to exogenous than endogenous abrasives.
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Raue, Lars, and Helmut Klein. "Location Depending Textures of the Human Dental Enamel." Solid State Phenomena 160 (February 2010): 281–86. http://dx.doi.org/10.4028/www.scientific.net/ssp.160.281.
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Dental enamel is the most highly mineralised and hardest biological tissue in human body [1]. Dental enamel is made of hydroxylapatite (HAP) - Ca5(PO4)3(OH), which is hexagonal (6/m). The lattice parameters are a = b = 0.9418 nm und c = 0.6875 nm [1]. Although HAP is a very hard mineral, it can be dissolved easily in a process which is known as enamel demineralization by lactic acid produced by bacteria. Also the direct consumption of acid (e.g. citric, lactic or phosphoric acid in soft drinks) can harm the dental enamel in a similar way. These processes can damage the dental enamel. It will be dissolved completely and a cavity occurs. The cavity must then be cleaned and filled. It exists a lot of dental fillings, like gold, amalgam, ceramics or polymeric materials. After filling other dangers can occur: The mechanical properties of the materials used to fill cavities can differ strongly from the ones of the dental enamel itself. In the worst case, the filling of a tooth can damage the enamel of the opposite tooth by chewing if the interaction of enamel and filling is not equivalent, so that the harder fillings can abrade the softer enamel of the healthy tooth at the opposite side. This could be avoided if the anisotropic mechanical properties of dental enamel would be known in detail, hence then another filling could be searched or fabricated as an equivalent opponent for the dental enamel with equal properties. To find such a material, one has to characterise the properties of dental enamel first in detail for the different types of teeth (incisor, canine, premolar and molar). This is here exemplary done for a human incisor tooth by texture analysis with the program MAUD from 2D synchrotron transmission images [2,3,4].
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Lendenmann, U., J. Grogan, and F. G. Oppenheim. "Saliva and Dental Pellicle-A Review." Advances in Dental Research 14, no. 1 (December 2000): 22–28. http://dx.doi.org/10.1177/08959374000140010301.
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The acquired enamel pellicle is an organic film covering the surfaces of teeth. When this film was first discovered, it was thought to be of embryologic origin. Only in the middle of this century did it become clear that it was acquired after tooth eruption. Initially, the small amounts of material that could be obtained have virtually limited the investigation of pellicle proteins to amino acid analysis. Nevertheless, this technique revealed that the pellicle is mainly proteinaceous and is formed by selective adsorption of salivary proteins on tooth enamel. Later, immunologic techniques allowed for the identification of many salivary and fewer non-salivary proteins as constituents of pellicle. However, to this date, isolation and direct biochemical characterization of in vivo pellicle protein have not been possible, because only a few micrograms can be obtained from a single donor. Therefore, the composition and structure of the acquired enamel pellicle are still essentially unknown. Information on the functions of pellicle has been obtained mainly from in vitro experiments carried out with saliva-coated hydroxyapatite and enamel discs. It was found that pellicle protects enamel by reducing demineralization upon acid challenge. Improved pellicle harvesting procedures and analysis by state-of-the-art proteomics with mass spectroscopy approaches promise to make major inroads into the characterization of enamel pellicle.
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Al-Obaidi, Zainab Q., and Nada J. Radhi. "The impact of histopathological celiac disease activity on dental enamel defects and dental caries." Journal of Baghdad College of Dentistry 32, no. 1 (March 15, 2020): 51–56. http://dx.doi.org/10.26477/jbcd.v32i1.2758.
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Background: Celiac disease is an autoimmune chronic disease that affects the human’s intestine and subsequently reflects its effect on the entire body health by retardation the absorption and immune mediated complications cause the involvement of oral health. The present study intended to evaluate the impact of the histopathological disease activity upon dental enamel defects and dental caries.
Subjects and methods: Forty celiac-diseased patients aged 7-11 years were collected from 3 different teaching hospitals in Baghdad classified by means of the histopathological activity of the intestinal disease according to modified Marsh-Rostami classification. Dental enamel defects were measured by Aine’s classification, while dental caries experience and severity were measured using d1-4mfs/t and D1-4MFS/T.
Results: The majority of the sample came with partial villous atrophy of the small intestine (Marsh III-a) and almost half of the sample were with no celiac disease specific dental enamel defects (Aine’s 0), while Aine’s I was the most predominant than Aine’s II. Most missed surfaces due to dental caries in permanent teeth came with Marsh II.
Conclusion: The more the severity of celiac disease histopathological activity the more the severity of celiac specific dental enamel defects and the less experienced dental caries.
Keywords: Celiac disease, histopathological activity, dental enamel defects, dental caries.
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Uhlen, M. M., A. Mulic, B. Holme, A. B. Tveit, and K. R. Stenhagen. "The Susceptibility to Dental Erosion Differs among Individuals." Caries Research 50, no. 2 (2016): 117–23. http://dx.doi.org/10.1159/000444400.
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Studies of wine tasters and patients with self-induced vomiting have revealed that 30-50% of individuals at high risk do not develop erosive lesions. The aim was to investigate this apparent individual susceptibility to enamel erosion. Two enamel specimens were made from each of 3 premolars from 8 persons (donors). Six acrylic mouth appliances were worn by 6 volunteers (carriers). One specimen from each donor was mounted on each appliance. The carriers wore the appliances for 9 days. The appliances were immersed in 0.01 M HCl for 3 min twice per day to imitate a vomiting/reflux situation. The enamel specimens were analysed by a white-light interferometer to measure enamel loss (in micrometres). The enamel loss varied significantly both between the donor teeth (p = 0.009) and the carriers (p = 0.004). The lesion in the specimen with the largest amount of enamel loss was 4 times as deep as in the specimen with the lowest. In 1 carrier, all specimens displayed enamel loss above the mean, including the specimen from the donor with the most resistant enamel. The variation in susceptibility to erosion among individuals appears to be influenced both by the sustainability of the enamel and by factors in the oral environment. This could explain the variation in prevalence and severity of dental erosions among patients exposed to similar acidic challenges. The results suggest that for certain individuals, only minimal acidic challenges may be sufficient to cause damage to the teeth, while others may never develop dental erosions despite extensive exposure to acid.
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Goodman, A. H. "Dental Enamel Hypoplasias in Prehistoric Populations." Advances in Dental Research 3, no. 2 (September 1989): 265–71. http://dx.doi.org/10.1177/08959374890030022801.
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Recent years have witnessed an impressive increase in research on enamel hypoplasias in archaeological populations. By reviewing a series of studies of enamel hypoplasias at Dickson Mounds, Illinois, North America (950-1300 A.D.), a prehistoric site involved in the transition from gathering-hunting to agriculture, this paper provides an illustration of this type of research. The location of linear hypoplasias on labial tooth surfaces of 111 adults was studied with a thin-tipped caliper, and this location was converted to an age at development. Most defects developed between two and four years of developmental age. Hypoplasias increased in prevalence from 45% in the pre-agriculture group to 80% in the agricultural group (p < 0.01). The transition to agriculture occurred at a cost to infant and childhood health. Defects are associated with decreased longevity. Individuals with defects have a life expectancy of nearly ten years fewer than those without defects, suggesting that the development of a defect marks a significant and lasting health event. Enamel hypoplasias occur most frequently on anterior teeth, polar teeth in developmental fields, and the middle developmental thirds of teeth. Analysis of these data suggests that enamel may be differentially susceptible to growth disruption and that susceptibility varies both within and among teeth. The study of enamel defects at Dickson provides insights into the health and nutritional consequences of the economic change from hunting and gathering to agriculture. More generally, with the availability of teeth from genetically homogeneous populations, studies of enamel hypoplasias in prehistory should provide a useful complement to research on this condition in contemporary peoples.
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Bartlett, John D. "Dental Enamel Development: Proteinases and Their Enamel Matrix Substrates." ISRN Dentistry 2013 (September 16, 2013): 1–24. http://dx.doi.org/10.1155/2013/684607.
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This review focuses on recent discoveries and delves in detail about what is known about each of the proteins (amelogenin, ameloblastin, and enamelin) and proteinases (matrix metalloproteinase-20 and kallikrein-related peptidase-4) that are secreted into the enamel matrix. After an overview of enamel development, this review focuses on these enamel proteins by describing their nomenclature, tissue expression, functions, proteinase activation, and proteinase substrate specificity. These proteins and their respective null mice and human mutations are also evaluated to shed light on the mechanisms that cause nonsyndromic enamel malformations termed amelogenesis imperfecta. Pertinent controversies are addressed. For example, do any of these proteins have a critical function in addition to their role in enamel development? Does amelogenin initiate crystallite growth, does it inhibit crystallite growth in width and thickness, or does it do neither? Detailed examination of the null mouse literature provides unmistakable clues and/or answers to these questions, and this data is thoroughly analyzed. Striking conclusions from this analysis reveal that widely held paradigms of enamel formation are inadequate. The final section of this review weaves the recent data into a plausible new mechanism by which these enamel matrix proteins support and promote enamel development.
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Rigo, Lilian, Leodinei Lodi, and Raíssa Rigo Garbin. "Differential diagnosis of dental fluorosis made by undergraduate dental students." Einstein (São Paulo) 13, no. 4 (December 2015): 547–54. http://dx.doi.org/10.1590/s1679-45082015ao3472.
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ABSTRACT Objective To check knowledge of undergraduate dental students to make diagnosis of dental fluorosis with varying degrees of severity and choose its appropriate treatment. Methods Data were collected using a semi-structured questionnaire addressing knowledge of undergraduates based on ten images of mouths presenting enamel changes. Results Only three images were correctly diagnosed by most undergraduates; the major difficulty was in establishing dental fluorosis severity degree. Conclusion Despite much information about fluorosis conveyed during the Dentistry training, as defined in the course syllabus, a significant part of the students was not able to differentiate it from other lesions; they did not demonstrate expertise as to defining severity of fluorosis and indications for treatment, and could not make the correct diagnosis of enamel surface changes.
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Naveen Kumar, PuvvadiGopalkrishna, PurviM Bhate, Rashmi Rai, and SyedaNikhat Mohammadi. "Enamel hypoplasia and dental caries." Annals of Tropical Medicine and Public Health 9, no. 2 (2016): 90. http://dx.doi.org/10.4103/1755-6783.177374.
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Leigh Krietsch Boerner. "What’s that stuff? Dental enamel." C&EN Global Enterprise 98, no. 41 (October 26, 2020): 24–25. http://dx.doi.org/10.1021/cen-09841-feature3.
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Risnes, Steinar. "Growth tracks in dental enamel." Journal of Human Evolution 35, no. 4-5 (October 1998): 331–50. http://dx.doi.org/10.1006/jhev.1998.0229.
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Ellwood, Roger Philip, and Denis O'Mullane. "Enamel Opacities and Dental Esthetics." Journal of Public Health Dentistry 55, no. 3 (June 1995): 171–76. http://dx.doi.org/10.1111/j.1752-7325.1995.tb02362.x.
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Koulourides, T., and M. C. Chien. "The ICT in situ Experimental Model in Dental Research." Journal of Dental Research 71, no. 3_suppl (April 1992): 822–27. http://dx.doi.org/10.1177/002203459207100s06.
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The intra-oral cariogenicity test (ICT) in situ experimental model was introduced in 1964 for the study of caries on sample enamel in the human mouth. Slabs of human or bovine enamel are mounted with a Dacron gauze cover in the acrylic flanges of prosthetic appliances. The extent of enamel demineralization or remineralization of lesions is assessed from surface microhardness measurements and microradiography of the enamel sections. The ICT model offers the potential of studying various parameters related to caries. This publication presents a typical ICT study comparing the cariogenicity of 10% sucrose solutions containing 1, 3, 10, and 30 ppm F with that of the control solution, 10% sucrose (without fluoride). The treatments were applied to the ICT as 10-minute extra-oral immersions. The results indicate: (1) a strong effect of F in decreasing demineralization of sound enamel and increasing remineralization of pre-softened enamel in the ICT; (2) pronounced resistance to a subsequent in vitro acid test; (3) pronounced F incorporation into pre-softened enamel; and (4) a characteristic acid-resistant zone, as seen in microradiographs, associated with exposure to F. This in situ model enables one to study experimental caries with repeated testing of enamel that follows the development and/or the regression of subsurface enamel lesions, F incorporation, increased acid resistance, cariogenicity of substrates, and other parameters of caries that can be assessed under standard conditions of tooth substrate and microbial sheltering.
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Al-Jawad, M., L. M. Simmons, Axel Steuwer, S. H. Kilcoyne, R. C. Shore, R. Cywinski, and David J. Wood. "Three Dimensional Mapping of Texture in Dental Enamel." Key Engineering Materials 361-363 (November 2007): 877–80. http://dx.doi.org/10.4028/www.scientific.net/kem.361-363.877.
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We have used synchrotron x-ray diffraction to study the crystal orientation in human dental enamel as a function of position within intact tooth sections. Keeping tooth sections intact has allowed us to construct 2D and 3D spatial distribution maps of the magnitude and orientation of texture in dental enamel. We have found that the enamel crystallites are most highly aligned at the expected occlusal points for a maxillary first premolar, and that the texture direction varies spatially in a three dimensional curling arrangement. Our results provide a model for texture in enamel which can aid researchers in developing dental composite materials for fillings and crowns with optimal characteristics for longevity, and will guide clinicians to the best method for drilling into enamel, in order to minimize weakening of remaining tooth structure, during dental restoration procedures.
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Hu, X. L., B. Ho, C. T. Lim, and C. S. Hsu. "Thermal Treatments Modulate Bacterial Adhesion to Dental Enamel." Journal of Dental Research 90, no. 12 (September 29, 2011): 1451–56. http://dx.doi.org/10.1177/0022034511424155.
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Numerous studies have demonstrated the effects of laser-induced heat on demineralization of enamel; however, no studies have investigated the link between heat/laser-induced changes in physicochemical properties and bacterial adhesion. In this study, we investigated the effects of thermal treatment on surface properties of enamel such as hydrophobicity and zeta potential. Bacterial adhesion to treated surfaces was characterized by confocal laser scanning microscopy, and adhesion force was quantified by atomic force microscopy. The hydrophobicity of enamel increased after heating (p < 0.05), and the zeta potential of heated enamel became more negative than that of the control (p < 0.01). Streptococcus oralis and S. mitis were more hydrophilic than S. sanguis, with more negative zeta potential (all p < 0.01). S. mitis and S. oralis occupied significantly less area on enamel after being heated (p < 0.05). Heating reduced the adhesion force of both S. mitis and S. oralis to enamel with or without saliva coating. Reduction of adhesion force was statistically significant for S. mitis (p < 0.01), whereas that of S. oralis was not statistically significant (p > 0.05). Heating did not affect the adhesion of S. sanguis with or without saliva coating. In conclusion, thermal treatment and photothermal/laser treatments may modulate the physicochemical properties of enamel, preventing the adhesion of some bacterial species.
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Kostyrenko, Oleksij P., Nataliia I. Vynnyk, Mykhailo M. Koptev, Petro A. Hasiuk, Maksym I. Skrypnyk, Alevtyna M. Bilous, and Serhii A. Proskurnya. "DENTAL CROWN BIOMINERALIZATION DURING ITS HISTOGENESIS." Wiadomości Lekarskie 73, no. 12 (2020): 2612–16. http://dx.doi.org/10.36740/wlek202012110.
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The aim: Thepaper wasaimedat thestudyof thebiomineralization processesofa permanentdental crown in thepostnatal period of histogenesis. Materials and methods: The study involved 30 culled puppies aged 30-40 days. To study the histogenesis of the germs of the permanent tooth from the cuticular epithelium in the postnatal period microscopic, electron microscopic, immunohistochemical methods of study have been used. Results: The studies show that in the postnatal period, the maturation of the germ of a permanent tooth starts with the synthesis of cells of the cuticular epithelium of the organic stroma, capable of subsequent mineralization. Differentiation of the proameloblasts, located on the surface of the dental papillary mesenchyma, at the early stages of histogenesis, is strongly associated with the appearance of a specific protein taftelin. Origination of secretory ameloblasts, which produce the protein enamelin, triggers the process of secondary biomineralization of the enamel. The terminal processes of the secretory ameloblasts produce the protein in the form of layers that overlap each other at a certain angle. Such layering of the structures of enamel and dentin contributes to the S-shaped maturation of the hard tooth tissues, strengthening them considerably. At the follicle stage, maturation of the dental crown, coated with cuticular epithelium, occurs. Invaginations of the cuticular epithelium form a characteristic topography of the dental crown, and enamel projections are further formed by the ameloblasts. Epitheliocytes of the inner layer of the enamel organ have desmosomal connections that allow the filtration of the salivary fluid at the stage of the enamel trophism. Conclusions: The findings of the study suggest that, normally, due to the cuticular epithelium, filtration of the salivary fluid occurs with protein deposition on it and subsequent infiltration of the calcium salts into the subjacent enamel.
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Raue, Lars, Helmut Klein, and Christiane Hartmann. "Elastic Modulus of Human Dental Enamel from Different Methods." International Journal of Biomaterials Research and Engineering 1, no. 1 (January 2011): 39–48. http://dx.doi.org/10.4018/ijbre.2011010104.
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Knowing the elastic modulus of human dental enamel is of high importance since dental filling materials should posses equal mechanical properties as enamel itself. If this demand is not fulfilled, the interaction between filling and enamel is not equivalent, so that healthy enamel could be simply abrased during chewing. Hence it is astonishing that the literature shows a big variety of suggestions for the elastic modulus. This paper will give a short overview about some existing results (maybe not all) and tries to compare and evaluate them. The experiments have been done too, trying to make it more easy for the experienced reader to make up his own mind about the elastic modulus of human dental enamel.
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Dowker, S. E. P., P. Anderson, J. C. Elliott, and X. J. Gao. "Crystal chemistry and dissolution of calcium phosphate in dental enamel." Mineralogical Magazine 63, no. 6 (December 1999): 791–800. http://dx.doi.org/10.1180/002646199548934.
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AbstractThe mineral component (at least 95 wt. %) of dental enamel is hydroxyapatite (hydroxylapatite) with multiple substitutions. The biogenic origin of enamel is reflected in the unusual ribbon-like morphology of the crystals, which are extremely elongated in the c-axis direction, and their organized arrangement within the tissue. The study of enamel dissolution has been driven by the very high prevalence of dental caries. In enamel caries, the initial demineralization results in subsurface dissolution of mineral. While the surface remains intact, reversal of the lesion by remineralization is possible. Problems of understanding the physico-chemical processes in enamel demineralization include the general problems concerning the structure and chemistry of apatites formed in aqueous media. Added to these are the general problem of dissolution in an inhomogeneous porous medium and the complication that enamel apatite has a naturally variable composition which changes during demineralization. The use of model systems in caries research is illustrated by reference to X-ray absorption studies of enamel and synthetic analogues.
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Shi, Jianmin, Arndt Klocke, Ming Zhang, and Ulrich Bismayer. "Thermally-induced structural modification of dental enamel apatite: Decomposition and transformation of carbonate groups." European Journal of Mineralogy 17, no. 5 (October 18, 2005): 769–76. http://dx.doi.org/10.1127/0935-1221/2005/0017-0769.
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Robinson, C., S. J. Brookes, J. Kirkham, W. A. Bonass, and R. C. Shore. "Crystal Growth in Dental Enamel: the Role of Amelogenins and Albumin." Advances in Dental Research 10, no. 2 (November 1996): 173–80. http://dx.doi.org/10.1177/08959374960100020901.
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Amelogenin-mineral interactions were investigated using an in vitro binding approach. Rat incisor enamel matrix proteins (mainly amelogenins) were dissolved in synthetic enamel fluid and allowed to equilibrate with deproteinised developing enamel crystals. The results showed that amlogenin proteins of 21, 23, 24, 26 and 27-kDa (corresponding to nascent and partially degraded amelogenins) were associated with the crystals whilst the lower Mr amelogenins (<21KDa) remained free in the synthetic enamel fluid. These data suggest the nascent and partially degraded amelogenins may interact with developing enamel crystals and could influence their growth. Albumin-mineral interactions were investigated by extracting developing rat incisor enamel with synthetic enamel fluid. Insoluble material (including the enamel crystals) was then further extracted with 0.1 M phosphate buffer (pH 7.4) to desorb any mineral bound proteins. Western blotting using anti-albumin antibodies showed that almost all of the albumin from the secretory stage enamel and a significant proportion of the albumin present in early transition stage was extractable in the synthetic enamel fluid. However. synthetic enamel fluid did not extract albumin from late transition or maturation stage tissue, which could only be removed following further extraction with phosphate buffer. Albumin degradation was apparent during the transition and maturation stages, where it is degraded and ultimately removed. This binding pattern may be related to amelogenin degradation and removal during the transition stage,. permitting albumin access to the previously obscured crystal surfaces. That the secretory stage matrix appears to "protect" secretory stage crystals from albumin may be an important consideration in the aetiology of enamel hypoplasias (i.e. incomplete crystal growth) and when using dissociative extraction procedures for the identification of mineral bound proteins.
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Gontijo, Leonardo, Roberval de Almeida Cruz, and Paulo Roberto Gomes Brandão. "Dental enamel around fixed orthodontic appliances after fluoride varnish application." Brazilian Dental Journal 18, no. 1 (2007): 49–53. http://dx.doi.org/10.1590/s0103-64402007000100011.
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Poor oral hygiene has been considered one of the main problems routinely faced in the orthodontic treatment. Orthodontic appliance creates an environment that provides mineral loss from the dental enamel. Such condition is clinically seen as white spot lesions and cavitations in the most severe cases. The aim of this study was to evaluate the effects of a fluoride varnish application as a caries prevention method for clinical orthodontics. The experiment analyzed dental enamel adjacent to orthodontics accessories after treatment. In addition, it was observed the calcium, phosphorus and fluoride contents on enamel treated with a fluoride varnish. The results showed that fluoride varnish application is a simple and fast technique that could be useful in preventing enamel demineralization associated to orthodontic treatment. Scanning electron microscopy revealed significant amount of calcium fluoride-like material deposited on enamel and energy dispersive x-ray analysis demonstrated a large incorporation of calcium and fluoride to the enamel of the treated specimens. It was concluded that fluoride varnish could indeed be considered an efficient preventive method to enhance enamel resistance against the cariogenic challenges during orthodontic therapy.
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Li, Quan-Zhou, Cheng-Yong Wang, Li-Juan Zheng, Dan-Na Zhao, and Chao-Feng Zeng. "Machinability of enamel under grinding process using diamond dental burrs." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 233, no. 11 (September 18, 2019): 1151–64. http://dx.doi.org/10.1177/0954411919873804.
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Enamel grinding is a critical dental surgery process. However, tooth damage during the process remains a significant problem. Grinding forces, burr wear, and surface quality were characterised in relation to grinding speed, enamel orientation, grinding depth, and burr grit grain size. Results indicated that enamel rod orientation, grinding depth, and grinding speed critically affected enamel grinding. Occlusal surface grinding resulted in significantly higher normal forces, surface roughness, and marginally greater tangential forces than axial surface grinding. Damage to enamel machined surfaces indicated the significant impact of diamond grit size and rod orientation. Burr wear was primarily diamond grit peeling off and breakage. Surface roughness of axial and occlusal sections was largely influenced by grinding speed and diamond grit size. Improving the surface quality of machined enamel surfaces could be realised using fine burrs, reducing the grinding speed and grinding depth, and adjusting the feed direction vertical to the rod orientation. Enamel surface quality and roughness could be improved by reducing brittle failure and circular runout during the grinding process, respectively.
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Richards, A., O. Fejerskov, and V. Baelum. "Enamel Fluoride in Relation To Severity of Human Dental Fluorosis." Advances in Dental Research 3, no. 2 (September 1989): 147–53. http://dx.doi.org/10.1177/08959374890030021301.
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The aim of this study was to test whether the concentrations of fluoride in fluorotic human enamel are related to the degree of severity of dental fluorosis classified according to the index described by Thylstrup and Fejerskov. Teeth representing the entire spectrum of human dental fluorosis were analyzed. Fluoride concentrations were determined by serial acid-etching from surface to interior of blocks of enamel cut from each tooth. Fluoride was measured by ion electrode and calcium by atomic absorption spectrophotometry. The results showed that the pattern of distribution of fluoride in fluorotic enamel is similar to that described for normal enamel. Increasing severity of fluorotic lesions was associated with increasing concentrations of fluoride throughout the enamel. It is concluded that although further studies are required to establish the relative contribution of fluoride which may be taken up posteruptively by fluorotic enamel, the findings support the hypothesis that the TF index reflects increasing exposure to fluoride during tooth development.
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Simmelink, J. W. "Ultrastructural Effects of Diphosphonates On Dental Enamel." Advances in Dental Research 1, no. 2 (December 1987): 356–65. http://dx.doi.org/10.1177/08959374870010022701.
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Initial experiments were designed to test the effects of two diphosphonates on acid dissolution of mature human enamel. Polished facets of enamel were treated with 10 mmol/L of EHDP or Cl2MDP (pH 7.4) for five min, H20-washed, acid-etched with 0.01 N lactic acid (pH 5.4) for 15 min, and examined in the scanning electron microscope. Controls were run with distilled H2O substituted for diphosphonates. In addition, the experimental window was outlined with lacquer, thus providing a reference to the original polished enamel surface. Results showed that EHDP markedly reduced enamel dissolution, with less than 1 μm of enamel removed, while Cl2MDP was similar to controls, with approximately 4-5 μm of enamel dissolved. It was decided to initiate further experiments with the objective of determining effects of diphosphonates on developing enamel during the secretory stage in rat molars. Five-day-old animals were injected s.c. with one of the following: EHDP, ADP, Cl2MDP, or NaCl (0.9% control). The diphosphonate dosages were 2.5, 5, 10, and 20 mg P/kg. Rat incisors were also examined in initial experiments on older rats (21-day) following daily s.c. injections of EHDP. Twenty-four hr after the injections, all rats were killed by perfusion fixation and routinely prepared with and without decalcification for light and transmission electron microscopy. Light microscopic examination of developing maxillary first molars frequently revealed subameloblastic cyst formation, which was used as an indicator of severe cellular alteration of overlying secretory ameloblasts. By this criterion, the EHDP- and ADP-treated rats showed more severe cellular effects at lower dosages (2.5 and 5 mg P/kg) than did the Cl2MDP-treated rats. In addition, when undecalcified sections were examined in the transmission electron microscope, disturbances in crystal formation were observed. Since both the cyst formation and the disturbed enamel beneath the cyst had many similarities to previous results reported on the effects of high doses of fluoride, the majority of results observed may be due to a non-specific cellular toxicity. However, some crystal growth effects appear to be specific for diphosphonates, as indicated by preliminary results with daily injections of EHDP. In the rat incisor, a definitive banding that shows both inhibition and return to more normal development within a 24-hour cycle has been detected. In the ultrastructure examination of undecalcified sections, the reaction to EHDP is clearly defined as bands of normal crystal size, electron density, and orientation alternating with disturbed bands of small crystal size and decreased electron density. The bands are approximately 2-3 μm in width.
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Ziscovici, Charles, Peter W. Lucas, Paul J. Constantino, Timothy G. Bromage, and Adam van Casteren. "Sea otter dental enamel is highly resistant to chipping due to its microstructure." Biology Letters 10, no. 10 (October 2014): 20140484. http://dx.doi.org/10.1098/rsbl.2014.0484.
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Dental enamel is prone to damage by chipping with large hard objects at forces that depend on chip size and enamel toughness. Experiments on modern human teeth have suggested that some ante-mortem chips on fossil hominin enamel were produced by bite forces near physiological maxima. Here, we show that equivalent chips in sea otter enamel require even higher forces than human enamel. Increased fracture resistance correlates with more intense enamel prism decussation, often seen also in some fossil hominins. It is possible therefore that enamel chips in such hominins may have formed at even greater forces than currently envisaged.
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Kelly, Ariana M., Anna Kallistova, Erika C. Küchler, Helena F. Romanos, Andrea Lips, Marcelo C. Costa, Adriana Modesto, and Alexandre R. Vieira. "Measuring the Microscopic Structures of Human Dental Enamel Can Predict Caries Experience." Journal of Personalized Medicine 10, no. 1 (February 2, 2020): 5. http://dx.doi.org/10.3390/jpm10010005.
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Objectives: The hierarchical structure of enamel gives insight on the properties of enamel and can influence its strength and ultimately caries experience. Currently, past caries experience is quantified using the decayed, missing, filled teeth/decayed, missing, filled surface (DMFT/DMFS for permanent teeth; dmft/dmfs for primary teeth), or international caries detection and assessment system (ICDAS) scores. By analyzing the structure of enamel, a new measurement can be utilized clinically to predict susceptibility to future caries experience based on a patient’s individual’s biomarkers. The purpose of this study was to test the hypothesis that number of prisms by square millimeter in enamel and average gap distance between prisms and interprismatic areas, influence caries experience through genetic variation of the genes involved in enamel formation. Materials and Methods: Scanning electron microscopy (SEM) images of enamel from primary teeth were used to measure (i) number of prisms by square millimeter and interprismatic spaces, (ii) prism density, and (iii) gap distances between prisms in the enamel samples. The measurements were tested to explore a genetic association with variants of selected genes and correlations with caries experience based on the individual’s DMFT+ dmft score and enamel microhardness at baseline, after an artificial lesion was created and after the artificial lesion was treated with fluoride. Results: Associations were found between variants of genes including ameloblastin, amelogenin, enamelin, tuftelin, tuftelin interactive protein 11, beta defensin 1, matrix metallopeptidase 20 and enamel structure variables measured (number of prisms by square millimeter in enamel and average gap distance between prisms and interprismatic areas). Significant correlations were found between caries experience and microhardness and enamel structure. Negative correlations were found between number of prisms by square millimeter and high caries experience (r value= −0.71), gap distance between prisms and the enamel microhardness after an artificial lesion was created (r value= −0.70), and gap distance between prisms and the enamel microhardness after an artificial lesion was created and then treated with fluoride (r value= −0.81). There was a positive correlation between number of prisms by square millimeter and prism density of the enamel (r value = 0.82). Conclusions: Our data support that genetic variation may impact enamel formation, and therefore influence susceptibility to dental caries and future caries experience. Clinical Relevance: The evaluation of enamel structure that may impact caries experience allows for hypothesizing that the identification of individuals at higher risk for dental caries and implementation of personalized preventative treatments may one day become a reality.
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Lacruz, Rodrigo S., Stefan Habelitz, J. Timothy Wright, and Michael L. Paine. "Dental Enamel Formation and Implications for Oral Health and Disease." Physiological Reviews 97, no. 3 (July 1, 2017): 939–93. http://dx.doi.org/10.1152/physrev.00030.2016.
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Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as weapons and/or tools as well as for food processing. Enamel development and mineralization is an intricate process tightly regulated by cells of the enamel organ called ameloblasts. These heavily polarized cells form a monolayer around the developing enamel tissue and move as a single forming front in specified directions as they lay down a proteinaceous matrix that serves as a template for crystal growth. Ameloblasts maintain intercellular connections creating a semi-permeable barrier that at one end (basal/proximal) receives nutrients and ions from blood vessels, and at the opposite end (secretory/apical/distal) forms extracellular crystals within specified pH conditions. In this unique environment, ameloblasts orchestrate crystal growth via multiple cellular activities including modulating the transport of minerals and ions, pH regulation, proteolysis, and endocytosis. In many vertebrates, the bulk of the enamel tissue volume is first formed and subsequently mineralized by these same cells as they retransform their morphology and function. Cell death by apoptosis and regression are the fates of many ameloblasts following enamel maturation, and what cells remain of the enamel organ are shed during tooth eruption, or are incorporated into the tooth’s epithelial attachment to the oral gingiva. In this review, we examine key aspects of dental enamel formation, from its developmental genesis to the ever-increasing wealth of data on the mechanisms mediating ionic transport, as well as the clinical outcomes resulting from abnormal ameloblast function.
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Richards, A., J. Kragstrup, K. Josephsen, and O. Fejerskov. "Dental Fluorosis Developed in Post-secretory Enamel." Journal of Dental Research 65, no. 12 (December 1986): 1406–9. http://dx.doi.org/10.1177/00220345860650120501.
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The aim of this study was to test whether dental fluorosis can be produced by administration of chronic doses of fluoride during only the post-secretory stage of enamel mineralization. Eight control and eight experimental pigs matched by weight and litter were fed a low-fluoride diet (<0.05 mg F-/kg b.w. daily) from weaning to slaughter at 14 months. The test group received an oral dose of 2 mg F -/kg b.w. per day from 8 months of age. Lower fourth pre-molars were at the post-secretory stage at the start of fluoride administration (confirmed by tetracycline marker) and were just erupting at slaughter. All of the fourth pre-molar teeth from the test group developed diffuse enamel hypomineralization indistinguishable from human fluorosis. No such lesions were seen in any of the teeth from the control animals. It was concluded that enamel fluorosis may be caused by fluoride exposure in the maturation phase only. The pathogenic mechanism may be an effect either on the selective loss of protein or on the influx of mineral, both of which occur during the post-secretory or maturation stage of enamel formation.
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Juniarti, Devi Eka. "Indirect veneer treatment of anterior maxillary teeth with enamel hypoplasia." Dental Journal (Majalah Kedokteran Gigi) 43, no. 3 (September 1, 2010): 157. http://dx.doi.org/10.20473/j.djmkg.v43.i3.p157-161.
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Background: Nowadays, aesthetic rehabilitation becomes a necessity. It is affected by patient’s background, especially career, social and economic status. The aesthetic abnormality of anterior teeth i.e discoloration, malposition and malformation can affect patient’s appearance, especially during smile. These dental abnormalities, as a result, can decrease patient’s performance. Dental malformation, for instance, can be caused by developmental tooth defect, such as enamel hypoplasia. Enamel hypoplasia is a developmental defect caused by the lack of matrix amount which leads to thin and porous enamel. Enamel hypoplasia can also be caused by matrix calcification disturbance starting from the formation and development of enamel matrix causing defect and permanent changes which can occur on one or more tooth. Purpose: The aim of the study is to improve dental discoloration and tooth surface texture on anterior maxillary teeth with enamel hypoplasia by using indirect veneer with porcelain material. Case: A 20 years-old woman with enamel hypoplasia came to the Dental Hospital, Faculty of Dentistry Airlangga University. The patient wanted to improve her anterior maxillary teeth. It is clinically known that there were some opaque white spots (chalky spotted) and porous on anterior teeth’s surface. Case management: Indirect veneer with porcelain material had been chosen as a restoration treatment which has excellent aesthetics and strength, and did not cause gingival irritation. As a result, the treatment could improve the confidence of the patient, and could also make their function normal. Conclusion: Indirect veneer is an effective treatment, which can improve patient’s appearance and self confidence.Latar belakang: Saat ini perbaikan estetik menjadi suatu kebutuhan. Kebutuhan akan estetik dipengaruhi latar belakang penderita, terutama karir, status sosial dan ekonomi. Hal ini disebabkan, kelainan estetik seperti diskolorasi, malposisi, malformasi, dapat mempengaruhi penampilan penderita terutama saat tersenyum. Kelainan gigi tersebut pada akhirnya dapat memperburuk penampilan penderita. Malformasi gigi dapat disebabkan oleh kelainan pada masa perkembangan gigi, misalnya hipoplasia enamel. Hipoplasia enamel adalah kelainan perkembangan yang disebabkan sedikitnya matriks enamel sehingga terjadi ketipisan dan porusnya enamel. Hipoplasia enamel dapat disebabkan gangguan kalsifikasi matriks saat pembentukan dan perkembangan matriks enamel, kerusakan dan perubahan permanen ini dapat melibatkan satu atau beberapa gigi. Tujuan: Tujuan perawatan ini memperbaiki diskolorasi dan tekstur permukaan gigi depan rahang atas akibat hipoplasia enamel menggunakan veneer indirek berbahan porselen. Kasus: Seorang penderita wanita 20 tahun dengan hipoplasia enamel datang ke Rumah Sakit Gigi dan Mulut Pendidikan Fakultas Kedokteran Gigi Universitas Airlangga. Penderita ingin memperbaiki gigi depan rahang atas yang secara klinis tampak bercak putih opak seperti kapur dan porus pada permukan labial gigi. Tatalaksana kasus: Veneer indirek dengan bahan porselen dipilih sebagai restorasi oleh karena segi estetik, kekuatan dan tidak mengiritasi ginggiva. Restorasi ini dapat meningkatkan kepercayaan diri penderita dan memperbaiki fungsi gigi. Kesimpulan: Veneer indirek merupakan perawatan yang efektif, dapat meningkatkan penampilan dan kepercayan diri penderita.
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Carey, C. M., G. L. Vogel, and L. C. Chow. "Permselectivity of Sound and Carious Human Dental Enamel as Measured by Membrane Potential." Journal of Dental Research 70, no. 12 (December 1991): 1479–85. http://dx.doi.org/10.1177/00220345910700120201.
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A microwell technique was used for determination of the permselectivities of sound and carious enamel in the same slice of tooth. The permselectivity determination was accomplished by drilling microwells in the enamel and filling them with a simulated plaque fluid containing lactate, carbonate, and inorganic ions at concentrations similar to those in resting plaque fluid, but with different concentrations of KCI. The electrical potentials developed across the enamel membrane were measured with microreference electrodes placed in the wells or in the solution outside the tooth. The results showed that the membrane potential was a function of the composition of the solutions separated by the enamel membrane and was independent of the composition of the solutions in the adjacent wells. The enamel was found to be cation-permselective, and sound enamel was more permselective than carious enamel. The flux rate of K+ was estimated from the change in the K+ concentration of the well solution as a function of time. The flux rate and the membrane potential data were used in the Nernst-Planck Flux Equation for calculation of the diffusion coefficient of K+ through enamel. The results indicate that the permselectivity of enamel can greatly influence the diffusion of ions through enamel membranes.
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Muşat, Viorica, Elena Maria Anghel, Agripina Zaharia, Irina Atkinson, Oana Cătălina Mocioiu, Mariana Buşilă, and Petrică Alexandru. "A Chitosan–Agarose Polysaccharide-Based Hydrogel for Biomimetic Remineralization of Dental Enamel." Biomolecules 11, no. 8 (August 2, 2021): 1137. http://dx.doi.org/10.3390/biom11081137.
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Developing multifunctional systems for the biomimetic remineralization of human enamel is a challenging task, since hydroxyapatite (HAP) rod structures of tooth enamel are difficult to replicate artificially. The paper presents the first report on the simultaneous use of chitosan (CS) and agarose (A) in a biopolymer-based hydrogel for the biomimetic remineralization of an acid-etched native enamel surface during 4–10-day immersion in artificial saliva with or without (control group) fluoride. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, Fourier transform infrared and Raman spectroscopies, X-ray diffraction, and microhardness tests were applied to investigate the properties of the acid-etched and remineralized dental enamel layers under A and CS-A hydrogels. The results show that all biomimetic epitaxial reconstructed layers consist mostly of a similar hierarchical HAP structure to the native enamel from nano- to microscale. An analogous Ca/P ratio (1.64) to natural tooth enamel and microhardness recovery of 77.4% of the enamel-like layer are obtained by a 7-day remineralization process in artificial saliva under CS-A hydrogels. The CS component reduced carbonation and moderated the formation of HAP nanorods in addition to providing an extracellular matrix to support growing enamel-like structures. Such activity lacked in samples exposed to A-hydrogel only. These data suggest the potential of the CS-A hydrogel in guiding the formation of hard tissues as dental enamel.
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Batista, Graziela Ribeiro, Carlos Rocha Gomes Torres, Beatrice Sener, Thomas Attin, and Annette Wiegand. "Artificial Saliva Formulations versus Human Saliva Pretreatment in Dental Erosion Experiments." Caries Research 50, no. 1 (2016): 78–86. http://dx.doi.org/10.1159/000443188.
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The aim of this study was to evaluate the erosion-preventive effect of different artificial saliva formulations and human saliva in vitro compared to human saliva in situ. In the in vitro experiment, bovine enamel and dentin specimens were stored in artificial saliva (4 different formulations, each n = 20), deionized water (n = 20) or human saliva (n = 6 enamel and dentin specimens/volunteer) for 120 min. In the in situ experiment, each of the 6 enamel and dentin specimens was worn intraorally by 10 volunteers for 120 min. The specimens were then eroded (HCl, pH 2.6, 60 s). Half of the specimens were subjected to microhardness analysis (enamel) and the determination of calcium release into the acid (enamel and dentin), while the other half were again placed in the respective medium or worn intraorally, respectively, for 120 min before a second erosion was performed. Knoop microhardness of enamel and the calcium release of enamel and dentin into the acid were again determined. Statistical analysis was conducted by two-way repeated-measures ANOVA or two-way ANOVA (α = 0.05). Enamel microhardness was not significantly different between all test groups after the first and the second erosive challenge, respectively. Enamel calcium loss was significantly lower in situ compared to the in vitro experiment, where there was no significant difference between all test groups. Dentin calcium loss was significantly lower than deionized water only after the first and than all except one artificial saliva after the second erosion. Under the conditions of this experiment, the use of artificial saliva formulations and human saliva in vitro does not reflect the intraoral situation in dental erosion experiments adequately.
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Chu, J. S., J. L. Fox, and W. I. Higuchi. "Quantitative Study of Fluoride Transport During Subsurface Dissolution of Dental Enamel." Journal of Dental Research 68, no. 1 (January 1989): 32–41. http://dx.doi.org/10.1177/00220345890680010501.
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Previous studies using bovine dental enamel as a model have shown that surface and subsurface dissolution of enamel may be governed by micro-environmental solution conditions. We have now investigated the demineralization phenomenon more rigorously with the primary objective of developing a method for deducing solution species concentration profiles as a function of time from appropriate experimental data. More specifically, in this report, a model-independent method is described for determination of the pore solution fluoride gradients in bovine enamel during subsurface demineralization. Microradiography was used to determine the mineral density profiles, and an electron microprobe technique to determine total fluoride (F) profiles associated with the enamel. In each case, matched sections of bovine enamel were exposed to partially saturated acetate buffers at pH = 4.5 containing 0.5 ppm F for various periods of time (from six to 24 hours). The treated enamel was found to have an intact surface layer and subsurface demineralization. The extent of the demineralization and the depths of the lesions increased with time in all cases. The data were farst used to calculate (a) the total F gradients in the enamel at various times, and (b) the local uptake rate of F as a function of time and position. Then, by manipulation of the equations describing the uptake and transport of F, we calculated the pore diffusion rate of F and the micro-environmental solution F concentration in the aqueous pores as a function of time and of distance from the enamel surface. It was also possible to calculate an intrinsic F diffusion coefficient in the pores, which was about 1.0 × 10-5 cm2/ sec, in good agreement with reported values. 14C-sucrose uptake and release experiments with identically prepared demineralized enamel sections were also conducted to provide an independent check on the assumed dependence of porosity on mineral density. The results of this investigation, especially the outcomes relative to this new method for determination of pore solution F gradients during acid attack of the dental enamel, should be valuable in future studies of the mechanism(s) of the action of F in inhibiting dental enamel demineralization.
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Farges, Jean-Christophe, Brigitte Alliot-Licht, Emmanuelle Renard, Maxime Ducret, Alexis Gaudin, Anthony J. Smith, and Paul R. Cooper. "Dental Pulp Defence and Repair Mechanisms in Dental Caries." Mediators of Inflammation 2015 (2015): 1–16. http://dx.doi.org/10.1155/2015/230251.
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Dental caries is a chronic infectious disease resulting from the penetration of oral bacteria into the enamel and dentin. Microorganisms subsequently trigger inflammatory responses in the dental pulp. These events can lead to pulp healing if the infection is not too severe following the removal of diseased enamel and dentin tissues and clinical restoration of the tooth. However, chronic inflammation often persists in the pulp despite treatment, inducing permanent loss of normal tissue and reducing innate repair capacities. For complete tooth healing the formation of a reactionary/reparative dentin barrier to distance and protect the pulp from infectious agents and restorative materials is required. Clinical andin vitroexperimental data clearly indicate that dentin barrier formation only occurs when pulp inflammation and infection are minimised, thus enabling reestablishment of tissue homeostasis and health. Therefore, promoting the resolution of pulp inflammation may provide a valuable therapeutic opportunity to ensure the sustainability of dental treatments. This paper focusses on key cellular and molecular mechanisms involved in pulp responses to bacteria and in the pulpal transition between caries-induced inflammation and dentinogenic-based repair. We report, using selected examples, different strategies potentially used by odontoblasts and specialized immune cells to combat dentin-invading bacteriain vivo.
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VENTURA, A., and S. MARTELOSSI. "Dental enamel defects and coeliac disease." Archives of Disease in Childhood 77, no. 1 (July 1, 1997): 91. http://dx.doi.org/10.1136/adc.77.1.91.
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