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1
Belfield, Louise Alicia. "Interactions between porphyromonas gingivalis and macrophages in oral pathology." Thesis, University of Plymouth, 2013. http://hdl.handle.net/10026.1/1611.
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Macrophages play a fundamental role in driving both inflammatory and immunosuppressive conditions of the oral mucosa. Periodontitis, a chronic inflammatory condition affecting the supporting structures of the teeth, is widely prevalent, affecting a large proportion of the global population, and has been linked to the development of systemic inflammatory diseases. Oral squamous cell carcinoma (OSCC) is placed sixth in the WHO rankings of cancer incidence worldwide, and despite continuing research into underlying mechanisms, incidence is on the rise. Aberrant macrophage function has been implicated in the pathogenesis of both diseases. On recruitment to sites of inflammation, macrophages become polarised within a spectrum of effector phenotypes depending on the factors they encounter in their microenvironment. These cells are highly plastic and continuously adapt their effector functions in response to locally derived stimuli. Mechanisms have been developed by pathogenic bacteria and transformed host tissues to exploit this plasticity and manipulate macrophage phenotype to facilitate disease progression. However, this plasticity is also available for therapeutic manipulation. The main objectives of this study therefore were to investigate the interactions between macrophages and pathogenic stimuli in the context of oral pathology with a view to identifying novel therapeutic targets. Firstly, a reproducible model of M1 and M2 macrophage polarisation using the THP-1 cell line was established to study their interactions with pathogenic stimuli. Treating the cells with combinations of PMA plus IFNγ or IL-4 for 24 hours led to two distinct populations of cells: PMA + IFNγ treated cells expressed higher levels of pro-inflammatory cytokines TNFα, IL-1β and IL-6, but lower levels of IL-10 and TGF-β, characteristic of M1 macrophages. PMA + IL-4 treated cells expressed lower levels of TNFα, IL-1β and IL-6 and higher levels of IL-10 and TGF-β, characteristic of M2 macrophages. As P. gingivalis LPS is present in the developing periodontal lesion, cytokine expression from macrophages exposed to LPS during polarisation was investigated. Exposure of macrophages to 1 μg/ml Pg LPS during polarisation led to a statistically significant down-regulation of inflammatory cytokines TNFα (10-, 4- and 5.5 –fold decrease in PMA, M1 and M2 cells, respectively) and IL-1β (1.9-, 2.0- and 1.5 –fold decrease in PMA, M1 and M2 macrophages, respectively) in response to subsequent stimulation with LPS. IL-6 production was not affected. The same pattern of cytokine down regulation was observed regardless of LPS species used, and in most cases, at a lower dose of 1 ng/ml LPS during polarisation. Finally, as macrophages recruited to the tumour environment will be influenced by tumour-secreted factors, the response of macrophages to LPS stimulation in the presence of OSCC conditioned media was examined. Contrariwise to polarisation with LPS, exposure of macrophages to OSCC produced factors during polarisation led to an amplification of IL-1β (13.8-, 2.3- and 8.8 –fold increase in PMA, M1 and M2 cells, respectively), and IL-6 (16.8-, 17.3- and 44.9 –fold increase in PMA, M1 and M2 cells, respectively), but not TNFα in response to LPS. Counter intuitively, these findings suggest that LPS manipulation of macrophage polarisation might result in a more M2 –like population of cells, whereas OSCC produced factors may result in a more M1- like population of cells. Viewed therapeutically, one short, single exposure of macrophages to LPS would up-regulate pro-inflammatory cytokines, whereas prolonged or chronic exposure would lead to the down-regulation of pro-inflammatory cytokines, therefore, LPS as a therapeutic modulator of macrophage function in an immunosuppressive (M2) environment to an inflammatory environment (M1) would only be viable as a single dose. For chronic inflammatory disease however, a repasted or prolonged exposure of macrophages to LPS skews macrophages to display a more M2-like cytokine profile and could dampen down detrimental pro-inflammatory cytokine production. The continued study of macrophage/ P. gingivalis interactions may shed light on pathogenic mechanisms not only in oral pathological conditions, but in a range of diseases.
2
Wolff, Ewan Douglas Stephens. "Oral pathology of the Archosauria bony abnormalities and phylogenetic inference /." Diss., Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/wolff/WolffE0507.pdf.
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3
Riffel, Amy Marie. "Osteoblasts aggregates cultivated in a 3-dimensional culture environment rigorously respond to Porphyromonas gingivalis culture supernatants." Thesis, University of Iowa, 2011. https://ir.uiowa.edu/etd/1067.
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An exciting alternative to the current methods for bone regeneration is osseous tissue engineering. One such method focuses on enhancement of osteoblast differentiation through rotary cell culture techniques. The response of osteoblast aggregates to periodontal microorganisms and their by-products will ultimately be important in their success as a method of bone regeneration. In this study, I hypothesize that human embryonic palatal mesenchymal (HEPM, ATCC 1486) pre-osteoblast cells produce different cytokine responses depending upon whether they are grown in a 2-dimensional tissue culture flask or a 3-dimensional tissue culture vessel and whether they are exposed to an un-inoculated, sterile Porphyromonas gingivalis growth medium or exposed to a 24 hour, sterile, P. gingivalis culture supernatant. Objectives: My objectives were first to determine and compare the cytokine response of HEPM, ATCC 1486 pre-osteoblast cells depending upon whether they are grown in a 2-dimensional tissue culture flask or a 3-dimensional tissue culture vessel and whether they are exposed to an un-inoculated, sterile P. gingivalis growth medium or exposed to a 24 hour, sterile, P. gingivalis culture supernatant. Methods: In 3 experiments, 5 X 106 HEPM, ATCC 1486 cells were grown in a 2-dimensional tissue culture flask or a 3-dimensional tissue culture vessel and exposed to an un-inoculated, sterile P. gingivalis growth medium or exposed to a 24 hour, sterile, P. gingivalis culture supernatant and incubated for 72 hours in 5% CO2 at 37oC. Media was removed from the tissue culture flasks or rotary vessels at 0, 1, 2, 4, 8, 12, 24, 36, 48, 60, and 72 hours to determine cytokine concentrations in the Luminex 100 IS Instrument (Luminex®, Austin, TX). HEPM, ATCC 1486 pre-osteoblast cell morphology was assessed by light and scanning electron microscopy at 96 hours. Results: In experiment 1, there were increases in IL-6 and IL-8. The IL-6 response of cells grown in a 2-dimensional tissue culture flask was higher than that of cells grown in a 3-dimensional tissue culture vessel. The IL-8 responses of the cells grown in 2-dimensional, 3-dimensional tissue culture were nearly identical. In light and scanning electron microscopy cells appeared normal and HEPM, ATCC 1486 pre-osteoblast cell aggregates were similar to that previously reported. In experiment 2, there were also increases in IL-6 and IL-8. The IL-6 and IL-8 responses of HEPM, ATCC 1486 pre-osteoblast cells grown in a 3-dimensional tissue culture vessel exposed to a 24-hour, sterile, P. gingivalis culture supernatant were higher than cells exposed to un-inoculated, sterile P. gingivalis growth media. In experiment 3, HEPM, ATCC 1486 pre-osteoblast cells grown in 2-dimensional tissue culture flasks and 3-dimensional tissue culture vessel exposed to a 24 hour, sterile, P. gingivalis culture supernatant produced high levels of IL-6, IL-8, and VEGF. Again, in light and scanning electron microscopy, cells appeared normal. Conclusion: HEPM, ATCC 1486 pre-osteoblast cells display different cytokine profiles depending upon the type of vessel they are cultured in. They also rigorously respond to P. gingivalis culture supernatants suggesting that they may respond to the presence of microorganisms commonly found in the oral cavity and play an active role in immunity during their integration following bone regeneration.
4
Chu, Rene. "Age and Sex-Related Differences in Dental Pulp Stem Cells." Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/4830.
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Objective: An in vitro study to determine the age and gender related changes of dental pulp stem cells in regards to proliferative capacity and lineage dependent effects on differentiation capabilities.
Material and Methods: Specimens have been collected from a population ranging from 16 yrs of age to 78 yrs of age. Intact, non-carious teeth were collected from the oral surgery department at College of Dentistry at the University of Iowa. A total of 20 specimens were collected. Teeth were collected, sectioned and pulpal tissue collected from the specimens. The pulpal tissue was cut and stored in phosphate buffered saline. The tissue was then subjected to enzymatic digestion and DPSC isolation. Subsequently cell cultures were grown, percentage of Stro-1+ cells and proliferation rate were measured. The DPSC were subjected to differentiation via osteogenic and adipogenic medium. The cells were assessed for osteogenic and adipogenic characteristics using RT- PCR and also replicative senescence using telomere length ratio measurement.
Results: Data suggests that with increasing age, there is a decreased proliferative capacity, decreased osteogenic capacity and shortened telomere length. There is no difference in the adipogenic potential and the percentage of DPSC present. There appears to be no difference in DPSCs in regards to proliferative capacity and differentiation potential with regards to gender. A possible gender related effect was noted in osteogenic potential and telomere length.
Conclusion: Increasing age has both a decreased proliferative effect and lineage dependent effects on DPSC differentiation potential. Thus this relationship must be accounted for when developing future regenerative therapies.
5
Tengan, Kelsey S. "Prospective, comparative assessment of alveolar ridge preservation using Guidor® Easy-Graft® Classic in atrumatic extraction socket." Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5861.
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Objectives: Tooth extraction initiates a cascade of biological events leading to the reduction of alveolar ridge volume. Alveolar ridge preservation (ARP) is a surgical treatment which aims at minimizing hard and soft tissue changes following tooth extraction. Several techniques and materials have been studied and used clinically in ARP. The selection of the biomaterials used for this technique is determined by several factors, such as features of the extraction site, inherent biomaterial properties and handling preferences by the surgeon, among others. The purpose of this study was to evaluate the efficacy of alveolar ridge preservation via the application of Easy-graft CLASSIC® (Sunstar Americas Inc.), an alloplastic bone substitute with unique handling features, following flapless posterior single tooth extraction compared to a particulate freeze-dried bone allograft (FDBA) covered with a collagen wound dressing, which has been advocated as a predictable treatment modality. The primary outcome in this study was bone volumetric reduction of the alveolar ridge assessed using cone beam computed tomography (CBCT) scans obtained at baseline and 16 weeks after tooth extraction and ARP.
Methods: This study is part of a multicenter study in collaboration with the University of Maryland School of Dentistry. Seventeen healthy adults treatment planned for a single tooth implants in the area posterior to the canines, excluding third molars, were recruited on the basis of an eligibility criteria. Patients were randomly assigned to the control group or the experimental group. Minimally traumatic extraction of the tooth was completed and the presence of an intact buccal plate of bone was verified. The control group received FDBA and the site was stabilized with a collagen wound dressing and sutures. The experimental group received Easy-graft CLASSIC® with no attempt to approximate the marginal mucosa. Healing was assessed after 1, 2, 4, 8, and 16 weeks. DICOM data was used to assess the alveolar ridge volume and linear changes from baseline to 16 weeks after ARP. Clinical measurements of the buccal gingival thickness, buccal alveolar bone thickness, keratinized gingiva, and socket dimensions were made at the time of the extraction and were subsequently analyzed for possible influences on the observed volumetric and linear outcomes.
Results: The mean alveolar ridge volume reduction from baseline to 16 weeks post operatively for the control and the experimental group was 114.96 mm3 and 94.87 mm3, respectively. These values correspond to a reduction of 9.59% for the control group and 13.04% for the experimental group. This difference did not reach statistical significance. The average loss of ridge width was 1.10mm for the FDBA and 1.24mm for the Easy-graft CLASSIC® with no statically significant differences between the two groups. The average loss of buccal bone height and lingual bone height in the FDBA group was 1.12mm and 0.63mm, respectively. Similarly, the average loss of buccal bone height and lingual bone height in the Easy-graft CLASSIC® was 1.19mm and 0.67mm, respectively. There was a weak to moderate positive correlation between buccal tissue thickness and the thickness of the buccal bone and a weak negative correlation between buccal bone thickness and alveolar ridge width reduction.
Conclusions: Within the limitations of this study, both treatment groups appear to be effective in alveolar ridge preservation and are associated with similar volumetric and linear bone reduction patterns.
6
Poulsen, Christopher. "Differential cytotoxicity of long-chain bases for human oral keratinocytes, fibroblasts, dendritic and oral squamous cell carcinoma cell lines." Thesis, University of Iowa, 2014. https://ir.uiowa.edu/etd/4723.
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Long-chain bases (sphingosine, dihydrosphingosine, and phytosphingosine) are present in the oral cavity and have potent antimicrobial activity against oral pathogens. However, little is known about their cytotoxicity for oral cells, an important step in considering their potential as future antimicrobial agents for oral infections.
In this study, primary oral keratinocytes, primary oral fibroblasts, dendritic cells, and oral squamous cell carcinoma cells were exposed to 10.0-640.0 µM long-chain bases and glycerol monolaurate (GML) in cell culture medium containing resazurin (e.g., Alamar Blue, Invitrogen Corp., Carlsbad, CA). Cell metabolism was assessed at 48 hours by the reduction of resazurin to resorufin. Percent cytotoxicity was defined as the median fluorescence intensity (MFI) of resazurin in cell culture media of cells treated with dilutions of long-chain bases/MFI of resazurin in cell culture media of untreated cells x 100, and the lethal dose 50 (LD50) was determined from the dose response curve where the 50 percent cytotoxicity intercepts with the long-chain base concentration on the x-axis.
For all cells, the LD50 (mean µM + std err) of sphingosine, dihydrosphingosine, phytosphingosine, and GML were 69.7 (1.7), 29.2 (1.7), 20.6 (1.7), and 134.3 (1.7), respectively. Primary oral keratinocytes were more resistant to long chain bases, whereas oral fibroblasts, dendritic cells, and oral squamous cell carcinoma cells were more susceptible.
Overall, long chain bases have LD50 for oral keratinocytes, oral fibroblasts, dendritic cells, and oral squamous cell carcinoma cells that are considerably higher than the minimal inhibitory concentrations for oral pathogens, a finding important to their future potential as therapeutics for prevention or treatment of periodontal disease infections.
7
Rinehart, Sarah. "Periodontal phenotype and supracrestal soft tissue dimensions – clinical correlations and their impact on post-extraction volumetric changes." Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5834.
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Objectives:
Extraction of a tooth leads to a series of healing events that are intimately associated with dimensional changes in the alveolar ridge that typically result in a net volume loss. Previous studies have evaluated the extent and pattern of those resorptive changes, however it remains challenging to predict the degree of change that will occur, as numerous local and systemic factors may play a role in the biologic events that follow tooth extraction. The purpose of this study was to assess the role that phenotypic characteristics of the periodontium play in the alveolar ridge remodeling processes that take place following single tooth extraction.
Methods:
Healthy patients in need of a single tooth extraction in the maxillary arch from second premolar to second premolar (inclusive) and who met a predefined eligibility criteria were enrolled in this study. An impression of the maxillary arch was made and a cone beam computed tomography (CBCT) scan of the maxilla was obtained immediately prior to tooth extraction at the baseline visit. At the time of the extraction, clinical measurements were made including probing depth, bone sounding, buccal keratinized mucosa width, buccal and palatal alveolar bone thickness, and buccal and palatal soft tissue thickness. Fourteen weeks following the baseline intervention, patients returned to the clinic for a second impression of the maxillary arch and a second CBCT of the maxilla. Linear and volumetric bone measurements were made using the data obtained from the CBCT scans. The casts obtained from the impressions were digitally scanned and volumetric measurements were made from the digitized data to assess volume changes of the residual ridge. The primary outcome of interest was the volumetric percent reduction of the alveolar ridge following single tooth extraction. Spearman correlations were utilized to evaluate relationships between variables and modeling was completed to predict the percentage of volumetric change in the hard and soft tissues using the clinical variables.
Results:
A total of 21 patients participated in the study, 19 patients are included in this analysis (one patient has yet to complete the study, one patient was later excluded due to lack of compliance). Of the 19 extraction sites included, 17 were maxillary premolar teeth. At baseline, the average buccal plate thickness was 1.09 mm. After 14 weeks, the average loss of alveolar bone width was 1.66 mm. The average loss of buccal bone height was 1.10 mm and mean loss of palatal bone height was 1.36 mm. The average percentage volumetric reduction of the bone as measured from a CBCT scan was 26.42% after 14 weeks of healing. Mean percentage volumetric reduction of the ridge, as measured from a digitized cast, was 18.89%. There was no statistically significant correlation noted between the bone and ridge volumetric measurements.
While there were no statistically significant correlations noted between the thickness of the buccal bone and the amount of volumetric remodeling, statistically significant negative correlations were found between the buccal bone thickness and the loss of alveolar bone width (rs = -0.66418, p-value = 0.0019). In addition, a statistically significant correlation was noted between the reduction in alveolar bone width and the loss of buccal ridge height (rs = 0.55707, p-value = 0.0132). Modeling methods found that increased thickness of the buccal soft tissue was predictive of increased percentage volumetric reduction of hard tissues (coeff = 37.24, p-value = 0.0301).
Conclusions:
Increased buccal soft tissue thickness was found to be predictive of increased percent volumetric reduction of alveolar bone. Thinner buccal bone was correlated with increased loss of alveolar bone width. While statistically significant correlations were identified, further studies with larger sample size are needed to better understand these relationships.
8
García, Loera José Miguel. "Patient satisfaction and oral health-related quality of life outcomes in edentulous patients being treated with complete dentures by dental students at the University of Iowa College of Dentistry and Dental Clinics." Thesis, University of Iowa, 2018. https://ir.uiowa.edu/etd/6421.
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Objectives:
The aim of this study is to investigate the impact of multiple factors in the Oral Health Related Quality of Life of patients being treated with Conventional Complete Dentures, including: a) Level of expertise of the dental provider (third year dental student vs. fourth year dental student); b) Length of time edentulous; c) Number of previous prostheses; d) Race; e) Sex; f) Age; g) Systemic conditions; h) Condition of the bone ridge; i) Economic factor and insurance coverage, in patients at the University of Iowa College of Dentistry (D3 and D4 Clinics).
Materials and methods:
Eighty-one subjects who had been completely edentulous (49 men and 32 women; age range from 23 to 93 years old, mean of 58.9+13) for a minimum of 3 months were recruited. Out of the eighty-one, eleven subjects were not included in the final analysis because their prostheses were not delivered due to various reasons (time, death, discontinued treatment). Subjects were asked to complete the OHIP-EDENT (Oral Health Impact Profile for Edentulous Patients) and the patient satisfaction questionnaire to record data at baseline, at 1-week post-delivery and at 1-month post-delivery of the new prostheses. Additional to these two instruments, the PDI Classification instrument (to assess bone/tissue condition) and the Kapur Index (to assess retention/stability of the new prostheses) were also used.
Baseline comparisons of subjects seen at the D3 vs. the D4 clinic were carried out using chi-square tests of association for nominal ordinal variables, and the Wilcoxon-Mann-Whitney test for ordinal and quantitative outcomes. Bivariate analyses were conducted to assess potential relationships between covariates and the primary outcomes (total OHIP-EDENT and total Patient Satisfaction Questionnaire scores at one-week and one-month follow-ups). The Spearman rank correlation was used to identify increasing or decreasing relationships between primary outcomes and quantitative and ordinal variables; the Wilcoxon-Mann-Whitney test was used to assess relationships between primary outcomes and categorical covariates.
Results:
Overall, there was not enough statistical evidence to conclude that patient satisfaction and quality of life were significantly affected by most of the factors being studied. However, there was suggestive evidence of the presence of higher level of quality of life for patients seen in the D4 clinic (students with higher level of expertise). At the one-month follow-up, the comparison of the total OHIP-EDENT score between the D3 and D4 clinics was significant at the 0.05 level (p=0.018, exact Wilcoxon-Mann-Whitney test). The total OHIP-EDENT scores tended to be lower (indicating greater satisfaction) in the subjects seen in the D4 clinic. Two of the nineteen items from the patient satisfaction questionnaires also suggested a greater level of patient satisfaction for patients seen in the D4 clinic (students with higher level of expertise).
Conclusion:
1) Oral health related quality of life at 1-week follow-up was not significantly different between patients treated by D3 and D4 students.
2) Oral health related quality of life at 1-week follow up was significantly better for patients who had been edentulous for a longer period of time than those who were recently edentulous. However, this result can only be considered suggestive due to the need for adjustment for multiple comparisons.
3) Oral health related quality of life at 1-month follow up was significantly better for patients treated by D4 students in comparison to D3 students. However, this result can only be considered suggestive due to the need for adjustment for multiple comparisons.
4) Overall, patient satisfaction at 1-week follow-up was not significantly different between patients treated by D3 and D4 students. However, patients treated in the D4 clinic reported significantly better outcomes in regard to speaking with their new prostheses.
5) Overall, patient satisfaction at 1-month follow-up was not significantly different between patients treated by D3 and D4 students. However, patients treated in the D4 clinic reported that they could chew better with their new prostheses compared to those treated by D3 students.
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Handoo, Nidhi Q. "Analysis of bone activity of jaws using scintigraphy on patients before, during and after treatment with IV bisphosphonates: a retrospective study." Thesis, University of Iowa, 2009. https://ir.uiowa.edu/etd/240.
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Bisphosphonates are non-metabolized compounds with high affinity for bone mineral hydroxyapatite. These compounds are used in diagnosis and treatment of malignancies metastatic to bone. Currently, IV bisphosphonates are used to treat hypercalcemia of malignancy. There are also "off label" uses to prevent, minimize, or delay skeletal morbidity associated with metastatic bone disease. Osteonecrosis of the jaws is an intraoral complication that has been reported after administration of intravenous nitrogen-containing bisphosphonates. Bisphosphonate associated osteonecrosis (BON) may remain asymptomatic for many weeks or months and is usually recognized clinically by the identification of exposed bone in the oral cavity. Other clinical features of BON are pain, ulceration, necrotic bone and/or local inflammation of the mucosa. Though these are generally all of which are seen later in the disease process. It is theorized that nuclear medicine imaging may play a crucial role in the recognition and identification of these bone lesions earlier in the disease process. Due to the high bone affinity, bisphosphonates coupled to a gamma-emitting radioisotope have been used as bone-scanning agents. Technetium is most commonly used gamma-emitting radioisotope in conjunction with a bisphosphonate. In University of Iowa Hospitals and Clinics, the material of choice is technetium99 methylene diophosphonate (Tc99 MDP). Bisphosphonates have a long half-life in bone and long-term treatment with non-tagged therapeutic bisphosphonates may saturate bone adherence sites and interfering with a single-dose scanning agent used for bone scintigraphy. Alternatively, therapeutic bisphosphonates may alter bone physiology such that scintigraphic findings could be enhanced in some locations and decreased in others. Limitations of the use of scintigraphy in patients on bisphosphonate therapy include low resolution and a difficulty in differentiating between inflammation and metastatic disease especially during the latter stages of the disease. In an effort to understand the effects of this compound on scintigraphic imaging, this study will evaluate any potential changes during and after use of IV bisphosphonates that may confound imaging.
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Anadioti, Evanthia. "Internal and marginal fit Of pressed and cad lithium disilicate crowns made from digital and conventional impressions." Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/2435.
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Objectives: The aim of the study was to evaluate in vitro the 3D and 2D marginal fit and 2D internal fit of CAD and Press all-ceramic crowns made from digital and conventional impressions.
Methods: A dentoform replica tooth (#30) was prepared for an all-ceramic crown (Master Die). 30 impressions were made with PVS material; 30 definitive casts were poured in type IV gypsum. 30 LavaTM C.O.S. impressions were made; 30 resin models were produced. 30 crowns were waxed and pressed in lithium disilicate (IPS e.max Press) (15 from each impression technique) and 30 crowns were milled from lithium disilicate blocks (IPS e.max CAD) (15 from each impression technique) utilizing the E4D scanner and milling engine. The Master Die and the intaglio of the 60 crowns were digitized using a 3D laser coordinate measurement machine (CMM). For each specimen a separate data set was created for the Qualify 2012 software. The two data sets, digital master die and digital intaglio of the crown, were merged using Best-Fit alignment. An area above the cavosurface margin with 0.75mm occlusal-gingival width circumferentially was defined. The 3D marginal fit of each specimen was an average of all 3D measurement values on that specified area for all the crowns, and it was used for the statistical analysis. For the 2D measurements, two sections, one facial-lingual and one mesial-distal, were made through the grooves on the standardized metal base of the tooth. The distance between the die and the intaglio surface of the crown were measured at 7 standardize points (2 on the margins, 2 at 0.75mm above the margin, 2 on the axial walls and 1 on the occlusal surface). For the 3D measurements one-way ANOVA with post-hoc Tukey's HSD test was used to determine whether there were significant differences in mean marginal fit values among four experimental groups (alpha=0.05). For the 2D data, a two-way ANOVA was performed to detect a significant interaction between the type of impressions and the type of crowns on the marginal and internal fit (alpha=0.05).
Results: One-way ANOVA revealed that the 3D mean marginal fit for Group A (0.048mm±SD 0.009) was significantly lower than those obtained from other three experimental groups Group B (0.088mm±SD 0.024), Group C (0.089mm±SD 0.020) and Group D (0.084mm±SD 0.021), while no significant differences were found among Group B, C and D. Similar results were found regarding the 2D marginal fit Group A (0.040mm±SD 0.008), Group B (0.076mm±SD 0.0234), Group C (0.075mm±SD 0.0148) and Group D (0.073mm±SD 0.0258). For the 2D internal fit, Group C (0.2109mm±SD 0.0410) had statistically significant poorer internal fit than the other three groups Group A (0.1105mm±SD 0.0474), Group B (0.1158±SD 0.02) and Group D (0.1454MM±SD 0.0245), while no significant difference was found among those three groups.
Conclusions: The combination of PVS impression method and Press fabrication technique produced the most accurate 3D and 2D marginal adaptation. The combination of LavaTM C.O.S. impression and Press fabrication technique produced the poorer 2D internal fit.
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Abdelaal, Maged Mohamed Elsayed. "Effect of post- processing heat treatment on flexural strength of zirconia for dental applications." Thesis, University of Iowa, 2016. https://ir.uiowa.edu/etd/3031.
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Purpose: the purpose of this study was to evaluate the effect of annealing heat treatment on biaxial flexural strength and reliability of 3Y-TZP, sintered at various temperatures.
Materials & methods: 3Y-TZP blanks were pre-sintered at 850°C for 2 hours and sliced into discs (20x1.2mm). Specimens were randomly assigned to 5 groups and subsequently sintered at various temperatures ranging from 1350°C to 1650°C for 2 hours. For each sintering temperature, specimens were divided into three treatment groups. One group (n=20) was left as-sintered as control. One group was air-abraded with 50 micron aluminum oxide powder (n=20). The last group was air-abraded and heat-treated at 1250°C for 20 minutes (n=20). In addition, polished specimens (n=5 per sintering temperature) were prepared to study microstructure, grain size and indentation crack patterns. The mean density was measured by helium pycnometry. The percent porosity was calculated from measured and theoretical density. The mean grain size was determined by the linear intercept method on atomic force micrographs. Crystalline phases were analyzed by x-ray diffraction (XRD). Biaxial flexural strength (BFS) was tested according to ISO standard 6872 using a Universal Testing Machine. Polished specimens were thermally etched, gold coated and Vickers indentations were produced under a 98N load. Indentation crack patterns were analyzed by Scanning Electron Microscopy (SEM) on digital images. The length ratio of trans-granular to inter-granular fracture was determined. Results were analyzed by Kruskal-Wallis test and Turkey's adjustment for multiple comparisons. A 0.05 level of segnificance was used. Reliability was evaluated by weibull analysis.
Results: There was an inverse relationship between density and sintering temperature Spearman rank correlation r = -0.982, p<0.0001). Statistically significant differences were found between all the groups (p<0.0001, exact Kruskal-Wallis test). There was strong evidence of an increase in the percentage of porosity with increasing sintering temperature Spearman rank correlation r=1.00, exact p = 0.017). The mean real grain size increased with sintering temperature. Analysis of XRD data showed that the monoclinic phase as well as ferro-elastic domain switching were present for all air-abraded groups. A small amount of monoclinic phase was also present in groups sintered at 1600°C and 1650°C. In The mean BFS was higher for all air-abraded groups compared to as-sintered or air abraded and heat-treated groups. Air-abraded groups sintered at 1350, 1450, 1550, and 1600°C showed the highest mean BFS (1552.97±200.85, 1502.29±102.36, 1391.4±108.3, 1258.5±114.8 MPa), respectively. The highest Weibull moduli (reliability) were obtained with the heat-treated group sintered at 1550°C (19.8), air-abraded group sintered at 1450°C (17.6) and heat-treated group sintered at 1350°C (15.4). The group sintered at 1650°C was the least reliable, independently of treatment state. Based on the data analysis of both the biaxial flexural strength and Weibull modulus, it was found that, the optimal treatment combination was obtained for the air-abraded group sintered at 1450°C, followed by the air-abraded group sintered at 1550°C. Crack patterns analyses showed that the proportion of trans-granular fracture increased with sintering temperature.
Conclusions: Annealing heat treatment is not recommended after any adjustments, as it does not improve the reliability of the material. Crack patterns and flexural strength are strongly influenced by the crystalline phase composition of the material. Sintering at 1600°C and 1650°C is not recommended due to the corresponding decrease in mechanical properties independently of treatment. Air-abrasion of zirconia sintered at 1450°C or 1550°C led to the best combination of high strength and reliability.
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Gohari, Homayon, and Kamran Haddad. "Oral hälsa hos vuxna diabetiker." Thesis, Karlstad University, Faculty of Social and Life Sciences, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-2263.
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Bakgrund: Diabetes är en kronisk sjukdom och mer än 150 miljoner i världen har sjukdomen. Diabetessjukdomen försämrar både den allmänna och den orala hälsan. Diabetikernas kunskaper om sjukdomens negativa effekter på munhälsan är bristfällig. Syfte: var att beskriva hur vuxna individers orala hälsa påverkas av diabetes och vad tandhygienister ska beakta vid en tandvårdsbehandling. Frågeställningar: Vilka är de orala komplikationerna hos vuxna individer med diabetes? Kan parodontitbehandling hos diabetiker ha positiva effekter på diabetessjukdomen? Vad bör tandhygienister särskilt ta hänsyn till vid behandling av diabetiker? Metod: Studien har genomförts som en systematisk litteraturstudie. Resultat: Parodontala sjukdomar är den dominerande orala komplikationen hos diabetiker. Diabetiker som är rökare har svårare parodontala sjukdomar än de som inte röker. Liksom parodontit förekommer karies hos diabetiker men är inte lika omfattande studerad som de parodontala sjukdomarna. Diabetiker med bättre metabolismkontroll har bättre oral hälsa. Många diabetiker har dåliga kunskaper om att diabetessjukdomen kan ha negativ effekt på deras orala hälsa. Konklusion: Diabetiker har behov av både parodontala behandlingar och hälsofrämjande och förebyggande insatser. Ett samarbete mellan tandvård och sjukvård är nödvändig.
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Scott, David 1964 Jan 11. "Virulence factors of oral anaerobic spirochetes." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34446.
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The research work presented in this thesis involved the examination of several fundamental questions concerning the role of oral anaerobic spirochetes (OAS) in the etiology of periodontal disease (PD). OAS are unusual, helical, Gram-negative bacteria that are considered putative periodontopathogens due to numerical association with diseased sites and the enzymatic arsenal available to OAS that appears consistent with disease symptoms. T. denticola is the most commonly isolated OAS from periodontal pockets and as such is the focus of most investigations into the role of OAS in PD.As free iron is severely limited in humans the means by which OAS may obtain sufficient iron to prosper in the sub-gingiva was examined. The resultant model suggests T. denticola obtains iron through the $ beta$-hemolysis of erythrocytes and the binding of liberated hemin by a 47-kDa outer membrane sheath (OMS) protein. The kinetics of the ligand-receptor interaction are presented and the receptor has been purified to apparent homogeneity from T. denticola. $ sp3$H-labeled hemin is not transported into the cell. Evidence is presented to show that T. denticola produces an iron reductase, which may facilitate the transport of ferrous iron across biological membranes. It is also shown that T. denticola (Td), T. vincentii (Tv) and T. socranskii (Ts) do not produce siderophores. In growth assays, under conditions of iron-limitation, T. denticola may use inorganic iron, a source unlikely to be available in vivo.
Hyaluronidase (Hase) activity is elevated in the gingival crevice during episodes of disease. Hase, when injected into the periodontal cavity under experimental conditions has been shown to result in connective tissue degradation. It is also known that T. pallidum, the agent of syphilis, produces a Hase that is critical to pathogenesis. Evidence is presented herein to show that Td, Tv and Ts all produce a hyauronoglucosaminidase (HGase). The identity and specificity of the Td HGase is confirmed through the use of enzyme inhibitors and activators, by electron microscope observations of the enzyme using the Hase inhibitor gold sodium thiomalate and anti-Apis mellifera venom antibodies and examination of the purity of the HA substrate using other polysaccharide degrading enzymes. As the HGase of these OAS would not migrate through a substrate-SDS PAGE system, we have employed hyaluronate (HA)- and chondroitin sulfate (CS)-absorbed nitrocellulose membranes to visualize HGase activity. The 59 kDa HGase of Td has been purified to apparent homogeneity through the conjugation of HA and CS to Affigel 701 beads.
The last subject to be addressed by this thesis pertains to the ultrastructure of oral spirochetes. Using the copper-containing dye, Alcian blue, we have shown that T. denticola produces an exopolysaccharide layer, in an electron microscopy investigation. The development of a stain for dark-field microscopy has simplified the observation of this layer. The exopolysaccharide layer may have relevance to the evasion of phagocytosis, to protection against colicins, immunoglobulins and bacteriophages, to adherence and perhaps to the immunogenicity of OAS inhabiting the sub-gingiva.
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Insalaco, Deborah Michelle. "Multiple oral re-reading for subjects with alexia." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/289086.
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This series of case studies explored the relationship between reading profiles and the benefits of text reading treatment. This research was motivated by the finding that some subjects with deep alexia read aloud words presented in a text context more accurately than words presented in isolation (Silverberg, Vigliocco, Insalaco, & Garrett, 1998). The benefit, which was specific to closed class elements, was consistent with a model of sentence production that hypothesizes that open and closed class elements are retrieved differently (Garrett, 1984, 1990). The treatment method used, Multiple Oral Re-reading (MOR) (Moyer, 1979), was known to improve reading rate for subjects with word length effects (Beeson, 1998; Tuomainen & Laine, 1991) and may have been an influence in changing reading processes for subjects with word length and grammatical class effects (Beeson & Insalaco, 1999). Further, oral reading treatment employing text as stimuli was demonstrated to improve other language processes including auditory comprehension and spoken language (Cherney, 1995; Cherney, Merbitz, & Grip, 1986). Thus, the goals of this study were to determine who benefited particularly from text treatment and whether text treatment influenced other reading and language processes. Six subjects with acquired alexia associated with stroke participated in an AB case study design that included a baseline observation period between initial assessment and treatment. After the baseline period, they received 10 weeks of MOR treatment. Treatment was followed by assessment. Of the six subjects, three had grammatical class effects during single word reading (MW, ED, MEL). One of them (MW) improved oral reading rate and accuracy for single words and text at post-treatment testing. The fourth subject (MB), who read text more accurately and more quickly than single words, but did not have a grammatical class effect, did not change oral reading rate or accuracy, but during treatment increased the complexity of his pleasure reading. A fifth subject (SM) increased accuracy of oral reading of closed class elements at post-treatment assessment and was able to use that skill as a scaffold for improved spoken language. The sixth subject (LW) was already a highly accurate reader and showed no change, but continued to practice oral reading as an exercise.
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Alkindi, Mohammed. "Effects of soluble factors released by oral squamos cell carcinoma on osteoclasts." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103726.
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Objective: Bone invasion represent significant problem in managing head and neck cancers, however the mechanisms of interactions between oral squamous cell carcinoma (OSCC) and bone cells are poorly understood. We hypothesized that tumor cells can directly stimulate osteoclastogenesis. Methods: OSCC cell lines, bone-invasive BHY and metastatic but not bone-invasive HN were cultured and conditioned medium (CM) was collected. Osteoclast formation from RAW 264.7 mouse monocytic cell-line was assessed. Results: When RAW 264.7 were primed with receptor activator of nuclear factor κB ligand (RANKL) and then treated with BHY-CM, marked 2-6 fold induction of osteoclastogenesis was observed. In contrast, HN-CM did not significantly affect osteoclastogenesis. In addition, BHY-CM, but not HN-CM promoted survival of mature osteoclasts. Using pharmacological inhibitors, we found that Protein kinase C (PKC)/Extracellular signal-regulated kinase (ERK)1/2/Mitogen activated protein kinase (MAPK) p38 as well as Phosphatidyl-inositol 3-kinases (PI3K)/Serine/threonine protein kinase Akt/Mammalian target of rapamycin (mTOR) pathways mediate BHY-CM induced osteoclastogenesis. Conclusion: OSCC-cells produce soluble factors that stimulate osteoclastogenesis from RANKL-primed precursors. Tumor-derived factors act by stimulating ERK1/2 and p38 MAPK pathways in osteoclast precursors.Objectif: L'invasion du tissu osseux est un problème majeur dans le traitement des cancers de la tête et du cou, cependant les mécanismes d'interactions entre le carcinome de cellules de squamous oral (OSCC) et les cellules du tissu osseux sont mal compris. Nous avons posé comme hypothèse que les cellules tumorales peuvent stimuler directement le phénomène d'ostéoclastogenèse. Méthodes: Deux différentes populations cellulaires de la lignée OSCC furent utilisées: les cellules BHY ayant un potentiel de colonisation du tissu osseux et les cellules HN ayant un potentiel métastatique mais non colonisant. Ces deux lignées cellulaires ont été cultivées et le milieu de culture conditionné (CM) a été collecté. La formation de cellules ostéoclastiques à partir de cellules de la lignée monocytaire de souris RAW 264.7 a été évaluée. Résultats: Une augmentation significative du phénomène d'ostéoclastogenèse d'un facteur 2 à 6 fut observée lors d'une activation des cellules RAW 264.7 avec RANKL suivit d'un traitement avec BHY-CM. De plus, la survie des cellules ostéoclastiques matures était favorisée en présence de BHY-CM uniquement. L'utilisation d'inhibiteurs pharmacologiques nous a permis de mettre en évidence que la stimulation du phénomène d'ostéoclastogenèse induite par BHY-CM est médiée par les voies de signalisations PKC/ERK/p38 et PI3K/AKT/mTOR. Conclusion : Les cellules OSCC produisent des facteurs solubles stimulant la formation d'ostéoclastes à partir de précurseurs activées par RANKL. Les facteurs dérivés de tumeurs agissent en stimulant les voies de signalisation ERK1/2 et p38 dans les précurseurs ostéoclastiques.
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Gonzalez, Shawneen M. "Cortical bone thickness in the maxilla and mandible for mini-implant placement." Thesis, University of Iowa, 2008. http://ir.uiowa.edu/etd/36.
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Anand, Sumeet M. 1978. "The correlation between tumour volume and survival in oral cavity and oropharyngeal squamous cell carcinoma /." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111587.
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The Tumour-Node-Metastasis (TNM) classification system of tumour stage does not always reflect the actual tumour mass present at diagnosis. Recent reports propose that volumetric analysis may allow improved stratification of disease recurrence and survival in head and neck squamous cell cancer (SCC). This study aims to assess the prognostic value of tumour volume on the outcome of patients with oral cavity and oropharyngeal SCC.A retrospective review of 73 patients was completed. Tumours were outlined semi-automatically in digitized computed tomography scans, and volumes computed based on surface triangulations of three-dimensional reconstructions with novel software developed at McGill.
Results illustrate significant interstage variability within the current TNM model. Moreover, in oral cavity and oropharyngeal SCC, tumour volume as well as T-stage are significant and independent predictors of disease free survival and overall survival.
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Fey, Marc E., Hugh W. Catts, Kerry Proctor-Williams, J. Bruce Tomblin, and Xuyang Zhang. "Oral and Written Story Composition Skills of Children With Language Impairment." Digital Commons @ East Tennessee State University, 2004. https://dc.etsu.edu/etsu-works/1776.
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In this study 538 children composed 1 oral and 1 written fictional story in both 2nd and 4th grades. Each child represented 1 of 4 diagnostic groups: typical language (TL), specific language impairment (SLI), nonspecific language impairment (NLI), or low nonverbal IQ (LNIQ). The stories of the TL group had more different words, more grammatical complexity, fewer errors, and more overall quality than either language-impaired group at either grade. Stories of the SLI and LNIQ groups were consistently stronger than were those of the NLI group. Kindergarten children with language impairment (LI) whose standardized test performance suggested normalization by 2nd grade also appeared to have recovered in storytelling abilities at that point. By 4th grade, however, these children's stories were less like the children with TL and more like those of children with persistent LI than they had been in 2nd grade. Oral stories were better than written stories in both grades, although the greatest gains from 2nd to 4th grade were generally made on written stories. Girls told stronger stories than did boys at both grades, regardless of group placement. It is concluded that story composition tasks are educationally relevant and should play a significant role in the evaluation of children with developmental LI.
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Gagen, O. Yu. "Treatment of concomitant pathology of the oral cavity in patients with maxillofacial injury." Thesis, БДМУ, 2020. http://dspace.bsmu.edu.ua:8080/xmlui/handle/123456789/17823.
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Stewart, Barry. "Experimental scrapie : comparison of pathology following oral and other parenteral routes of infection." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/22659.
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The aim of this project was to determine the effect that route of infection has on the incubation period and terminal pathology of experimental scrapie. Infection was established either by injection into the peritoneum or the biceps femoralis of the leg, or orally by administration of the agent with food. As a secondary study an experiment was devised to investigate the possible transport of scrapie infectivity in the central nervous system (CNS) of mice lacking a functional prn-p gene. The primary study was carried out using a combination of immunohistochemistry, histopathology and computerised image analysis. The study of agent transport was done by bioassay for reasons of sensitivity. C57B1 mice were infected with ME7 scrapie by the routes described above and groups of animals were serially sacrificed at between 5 and 7 timepoints during the course of the disease. The timepoints were chosen so that tissues representative of early, mid and late/terminal infection could be collected for study. Specific antibodies were used to detect the presence of PrP and GFAP whilst vacuolation was detected by standard haematoxylin and eosin staining. In the experiment to study the transport of infectivity in mice devoid of endogenous PrP the results suggest that some limited transport is possible. This is the result of a study using the projection of the optic nerve as a controlled system for assessing the transport of infectivity along defined neuroanatomical pathways. In conclusion, the results of the work described in this thesis show that oral infection, at least in experimental systems, is a highly efficient route of infection that results in significantly more severe pathology than either the intramuscular or intraperitoneal routes. The efficiency of oral infection may have implications for human disease with reference to new variant CJD (nvCJD).
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Mahrous, Ahmed. "The use of topical subgingival application of simvastatin gel in treatment of peri implant mucisitis : A pilot study." Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5561.
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Dentistry has come a long way from its humble beginnings. Like all other healthcare specialties, dentistry has evolved through the years. The understanding of physiology of dental health and disease has evolved allowing us to treat dental diseases much more efficiently. However not all dental problems are fully understood.
Diseases that affect the bone and soft tissue around teeth and dental implants, also known as “periodontal” and peri-implant” diseases respectively, have proven to be among the least understood and challenging dental diseases to treat. Recent advancements in microbiology and immunology have revealed that periodontal and peri implant disease have a plethora of interactions between the invading bacteria, the defensive human cells, and signaling micro molecules that control inflammation. Those interactions have opened up a new frontier for researchers in dentistry, microbiology, immunology, pharmacology and dental materials to understand these interactions and explore possible new treatments.
Simvastatin is a commonly prescribed drug used to control blood cholesterol. Recent research has revealed that simvastatin also possesses potent anti-inflammatory properties, and research has shown that topical application simvastatin is effective at controlling inflammation around teeth with periodontitis. However it has not yet been tested around dental implants with peri-implant disease. Thus the purpose of the current study is to investigate the effect of topical simvastatin on implants with peri-implant inflammation
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Elgreatly, Amira. "Management of initial caries lesions: Iowa survey." Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5403.
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The purpose of this study was to investigate factors related to Iowa dentists’ management of initial caries lesions for low, moderate and high-risk patients and their agreement with the International Caries Classification and Management System (ICCMS) Guidelines.
A survey with three patient scenarios (low, moderate and high-risk) was electronically sent to 916 University of Iowa alumni dentists who were in active practice. Information on dentists’ demographics and practice characteristics were also collected in the survey. Descriptive statistics were conducted to profile the variables of interest. Bivariate analyses were performed to assess the factors associated with the management of initial caries lesions for each scenario.
138 (response rate=15%; male=83 and female=55) practicing dentists in Iowa completed the survey. Of these (mean age= 48.3±12.3 years, mean years of clinical practice= 21.4±12.5), 30.4% completed a formal post-graduate training program, and 35.5% were solo practitioners. Agreement with ICCMS guidelines regarding the management of initial caries lesions for low, moderate and high-risk scenarios was approximately 73%, 59%, and 51% respectively. Odds of having agreement with ICCMS in the low risk scenario for those who frequently dry the tooth was 3.56 times that of those who don’t dry the tooth for caries detection (p=0.0468). Odds of having agreement with ICCMS in the moderate risk for those who graduated < 20 years ago was 6 times that of those who graduated >20 years ago (p=0.0024). Odds of having agreement with ICCMS in the moderate risk scenario for those who practiced in public health setting was 14 times that of those who practiced in solo or group practices (p=0.0089) and for those who frequently used magnification was 2.9 times that of those who don’t use magnification (p=0.0225). Odds of having agreement with ICCMS in the high risk scenario for those who frequently performed CRA was 2 times that of those who don’t perform CRA (p=0.0262).
The majority of Iowa dentists agreed with ICCMS guidelines in the non-surgical management of initial caries lesions regardless of patient risk level. Iowa dentists had the highest agreement with the ICCMS guidelines for low-risk scenario and agreement was associated with routinely drying teeth for caries detection. Evidence based decisions individualized for a patients’ risk status are essential for determining the best management of dental caries lesions.
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Aynapudi, Jessica. "Involvement of Signal Peptidase I in Streptococcus sanguinis Biofilm Formation." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4451.
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Biofilm accounts for 65%-80% of microbial infections in humans. Considerable evidence links biofilm formation to oral disease and consequently systemic infections. Eradication of biofilm-associated infections is important. Streptococcus sanguinis, a Gram-positive bacterium, is one of the most abundant species in oral biofilm. It contributes to biofilm development in oral cavities and is one of the recognized causes of infective endocarditis. To study and identify biofilm genes in S. sanguinis, biofilm formation of 51 mutants was compared with the wild type SK36 strain using crystal violet (CV) staining in a microtiter plate. Confocal laser scanning microscopy (CLSM) and image analysis was done to compare biofilm formation by the mutant to the wild type SK36 strain. A biofilm mutant XG2_0351, encoding a type I signal peptidase (SPase I), was further investigated. SPase I cleaves proteins that are transported through secretory machinery and is necessary for the release of translocated preproteins from a cytoplasmic site of synthesis to extracytoplasmic/membrane destinations. S. sanguinis, like many Gram-positive bacteria, has multiple SPases I. The objective of this project is to investigate the distinctive role that SPase I plays in biofilm formation in S. sanguinis. Using a plate reader, the growth curves of the wild type strain SK36 and XG2_0351 were compared. The scanning electron microscope (SEM) was utilized to compare the cell surface morphologies. Coomassie staining was done to narrow the list of potential substrates of XG2_0351. CV staining and CLSM images indicated phenotypic differences between the SPase I mutant and SK36. The growth curves of XG2_0351 and SK36 showed no significant difference although SEM illustrated a difference in the cell surface morphologies. Coomassie staining illustrated a number of substrates that were present in SK36 but not XG2_0351. In addition bioinformatics was used to understand the gene function. In conclusion, XG2_0351 reduces biofilm formation in S. sanguinis but further research is necessary to elucidate the specific proteins that are involved. Clarifying the vii role that SPase I plays in reduced biofilm formation in S. sanguinis will give a better understanding of the biofilm formation mechanism.
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Williams, A. Lynn. "Integrating Phonological Sensitivity Training and Oral Language within an Enhanced Dialogic Reading Approach." Digital Commons @ East Tennessee State University, 2006. https://www.amzn.com/1597560928/.
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Book Summary: This seminal text provides a scholarly overview of current evidence-based approaches to emergent literacy intervention as a component of clinical practice in speech-language pathology. The book's focus is primarily the emergent literacy period of development, transcending toddlerhood to the kindergarten year and corresponding to the years preceding formal literacy and reading instruction. By providing an accessible and usable integration of theory and research, it encourages readers to think about building early foundations in literacy to promote healthy early development and to ease children's transitions to later academic contexts. The book answers the question, "what can speech-language pathologists do today to include literacy as a target in childhood intervention?"
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Pintos, Vega Luis Javier. "Human papillomavirus infection and oral cancer : a case-control study." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84413.
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Introduction. Human papillomavirus (HPV) has been detected with varying frequency in oral cancers and in normal oral tissues. The main objective of the present study was to examine the association between HPV infection and risk of developing oral cancer.Methodology. This investigation, as a component of an international multi-centre study coordinated by the IARC, followed a hospital-based case-control design. Cases consisted of newly diagnosed patients with primary squamous cell carcinoma of the oral cavity, including mouth and oropharynx. Controls were frequency matched to cases by sex, age, and hospital. All subjects were interviewed to elicit detail information on known and putative risk factors.
Oral exfoliated cells were collected from all subjects for detection of HPV DNA using the PGMY09/11 PCR protocol. Antibodies against HPV 16, 18, and 31 capsids were detected in patients' plasma using an immunoassay technique. Logistic regression was used for estimation of odds ratios (ORs) and 95% confidence intervals (CI) of oral cancer for HPV and other candidate risk factors.
Results. A total of 72 cases and 129 controls were recruited. HPV DNA was detected in 19% of cases (14 out of 72), and in 5% of controls (6 out of 129). Analysis for cancers related to Waldeyer's ring (palatine tonsil and base of tongue) showed that the OR of disease for detection of high risk HPV types was 19.32 (95%CI:2.3--159.5), after adjustment for socio-demographic characteristics, tobacco and alcohol consumption. The adjusted OR of disease for HPV 16 seropositivity was 31.51 (95%CI:4.5--219.7). Analysis for non tonsillar oral cancers showed that the OR for detection of high risk HPV DNA in oral cells and for seropositivity were 2.14 (95%CI:0.4--13.0) and 3.16 (95%CI:0.8--13.0), respectively.
Discussion. The results from this study provide evidence supporting a strong association between HPV infection and cancers of the oropharynx, especially those arising from Waldeyer's ring. On the other hand, the association with non tonsillar oral cancers was of much lower magnitude. The biological evidence establishing a firm etiologic link remains to be established for the latter subsites, whereas the association between HPV and Waldeyer's ring carcinomas is consistent with a causal link.
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Paxton, Kellie. "Anesthetic efficacy of articaine hydrochloride versus lidocaine hydrochloride a meta-analysis /." Thesis, University of Iowa, 2008. http://ir.uiowa.edu/etd/22.
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Raina, Monica. "HBD3 regulates matrix metalloproteinase production in human myeloid dendritic cells exposed to Porphyromonas gingivalis hemagglutinin B." Thesis, University of Iowa, 2014. https://ir.uiowa.edu/etd/4729.
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Matrix metalloproteinases (MMP) are zinc- or calcium-dependent proteinases involved in the normal maintenance of the extracellular matrix. When elevated, MMPs degrade matrix components contributing to tissue destruction in infected periodontal sites.
The objectives of this study were two-fold: first to assess the ability of Porphyromonas gingivalis hemagglutinin B (HagB) to induce MMP responses in human myeloid dendritic cells and second, to assess the effect of host defense peptide human β defensin 3 (HBD3) to regulate and attenuate the MMP response of HagB treated dendritic cells. HBD3 (0.2, 2.0, or 20.0 µM) was given to primary dendritic cells pre-, co-, or post-treatment to HagB (0.02 or 0.2 µM). At 16 hours, MMP concentrations were determined. There were no significant differences in concentrations for all 3 replications for MMP-2 and -13. There were few significant differences in some of the replications for MMP-3, -7, and -9. There were more pronounced differences in MMP-1, -10, and -12 expression, which were significantly influenced by both the concentration of HBD3 and the timing of administration. Chemokine and cytokine responses were inversely related to MMP production. While MMP responses decreased in a dose related manner, chemokine responses were increased. Concentrations of MIP-1α were high and there were no differences in response to 0.02 and 0.2 M HagB with or without 20.0 M HBD3. However, the MIP-1β and TNFα response to 0.2 M HagB were only attenuated. HagB induces the production of MMPs in dendritic cells and treatment of dendritic cells with HBD3 can alter the profile of HagB-induced MMPs. Such a finding may have importance in the pathogenesis of periodontal disease.
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Swenson, Robert David. "The effects of bioprinting materials on HEPM cell proliferation and cytokine release." Thesis, University of Iowa, 2018. https://ir.uiowa.edu/etd/6299.
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Objectives: Three-dimensional (3D) bioprinting is a manufacturing process that incorporates viable cells into a 3D matrix by adding layer upon layer of material. The objectives of this study are to characterize a novel matrix of collagen and hydroxyapatite and to assess the effects of the 3D bioprinting process on cytotoxicity, proliferation rate, and cytokine expression of Homo sapiens palatal mesenchyme (HEPM) cells.
Methods: For this, we prepared a 3D matrix of collagen and hydroxyapatite without and with cells. We used light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to characterize the structure and arrangement of the collagen fibers. We then incubated the matrix with known standards of cytokines to measure adsorption. We assessed the proliferation and viability of HEPM cells in the presence of the 3D construct and after 3D bioprinting. Finally, we assessed the cytotoxicity of this matrix for HEPM cells and assessed its effect on the production of chemokines and cytokines. A one-way fixed effect ANOVA was fit to concentrations of cytokines and pairwise group comparisons were conducted using Tukey’s Honest Significant Differences test (p< 0.05).
Results: The matrix was found to contain interwoven strands of collagen and some hydroxyapatite crystals that did not absorb cytokines except for MIP-1a (p< 0.05). The matrix was found to be non-cytotoxic using an AlamarBlue® assay. We found that the cell proliferation rate was lower when seeded on the 3D construct than in 2D culture. We also found that the proliferation rate was very low for the HEPM cells in the 3D bioprinted constructs. In the presence of the 3D construct, the HEPM cells had similar expression profiles of the cytokines measured (P > 0.05 for GM-CSF, IL-6, IL-8, and RANTES).
Conclusion: 3D-bioprinting has the potential to be used in dentistry as a novel osteogenic bone grafting material. Here we show that a novel matrix of collagen and hydroxyapatite is non-cytotoxic to HEPM cells and does not induce a proinflammatory response.
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Khoo, Tuo Sheng Joel. "A comparison between a photographic shade analysis system and conventional visual shade matching method." Thesis, University of Iowa, 2015. https://ir.uiowa.edu/etd/1860.
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There are no previous studies validating the accuracy and repeatability of ClearMatch photographic shade analysis system. The purpose of this study was to compare the shade matches performed by a photographic shade analysis system (ClearMatch) with conventional visual shade matching method under simulated clinical conditions.
Three shade matching methods were used to match twelve shade tabs under simulated clinical conditions using a Vita Classical shade guide: conventional visual shade matching using 3 human raters (VM – Visual method), photographic shade analysis system (CM - ClearMatch) using two different ways of normalizing the image (CM-A2 and CM-ref respectively). Shade matching for all methods was completed at two separate sessions. The Kappa statistic was used to determine the intra-rater and inter-rater agreement. CIELAB values of the shade results were used to produce scatter plots as well as to calculate the color difference (delta E) between VM and CM groups.
There was no inter-rater agreement between VM and CM-A2 (k=0.000 and k=0.015 for the first and second sessions respectively) while VM and CM-ref showed weak agreement (k=0.244 and k=0.091 respectively). Intra-rater agreement was strong in all groups VM, CM-A2 and CM-ref (0.705, 0.803 and 0.681 respectively). CM-A2 had 2 (8.3%) shade matches with a delta E of less than 2.6 (clinically imperceptible), while CM-ref had 12 (50.0%) imperceptible matches. CM-A2 had an additional 16 (66.6%) shade matches with delta E of less than 5.5 (clinically acceptable), while CM-ref had 23 (95.8%) additional acceptable matches.
There was poor agreement in exact shade matches between conventional visual shade matching method and the photographic shade analysis system. The repeatability of the photographic shade analysis system was shown to be comparable to conventional visual shade matching. Using conventional shade matching as the gold standard, the capability of this photographic shade analysis system to accurately shade match has not been achieved.
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Heying, Jamie John. "Flexural strength of interim fixed prosthesis materials after simulated function." Thesis, University of Iowa, 2009. https://ir.uiowa.edu/etd/377.
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Statement of Problem
There are limited studies evaluating the effect of a cyclic load on interim fixed prosthetic materials and its effect on flexural strength.
Purpose of Study
1) To verify the flexural strength of previously studied interim fixed prosthetic materials.
2) To establish the flexural strength of new, advanced generation and untested interim fixed prosthetic materials.
3) To determine the effect of cyclic load on the flexural strength of interim fixed prosthetic materials.
Materials and Methods
Bar-type specimens of Caulk Temporary Bridge Resin, VitaVM CC, Protemp 3 Garant and Radica were fabricated according to International Standards Organization 4049 and American National Standards Institute/American Dental Association specification 27. After being stored in distilled water for 10 days, specimens were divided into Noncycled and Cycled Groups. The Noncycled Group specimens were fractured under a 3-point loading in a Bose Electroforce 3300 testing instrument at a crosshead speed of 0.75 mm/min. Cycled Groups specimens underwent a 6-12 Newton 3 Hertz cyclic load for 20,000 cycles in a Bose Electroforce 3300 testing instrument. Immediately following completion of the cycles, the specimens were fractured under a 3-point loading. Maximal loads to fracture in Newtons were recorded and mean flexural strengths were calculated (n = 20 per group). Comparisons were made with analysis of variance and Tukey's Multiple Comparison Test.
Results
Noncycled (NC) and Cycled (C) groups order of mean flexural strengths (MPa) from lowest to highest mean were as follows: Caulk (Noncycled - 53.83; C - 60.02), Vita VM CC (NC - 65.96; C - 66.83), Protemp 3 Garant (NC - 75.85; C - 77.18), and Radica (NC - 106.1; C - 115.96). In the Noncycled and Cycled groups, Radica was statistically superior when compared to all materials and Protemp 3 Garant was statistically superior to Caulk Temporary Bridge Resin. There was no statistically significant difference between the material's flexural strengths before and after cycles.
Conclusion
Within the limitations of this study, 20,000 cyclic loads of 6-12 Newtons at 3 Hertz did not have a significant effect on the flexural strength of interim fixed prosthetic materials. Radica demonstrated significantly superior flexural strength over other materials tested.
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Lanzel, Emily Anne. "Perineural invasion in mucoepidermoid carcinoma." Thesis, University of Iowa, 2015. https://ir.uiowa.edu/etd/1672.
Full textAbstract:
The objective of this study was to retrospectively evaluate the prevalence of perineural invasion in cases of mucoepidermoid carcinoma (MEC). The study will determine if previously assessed perineural invasion by original pathology reports would be increased by re-review of the originally hematoxylin-eosin-(H &E) stained slides as well as review of slides reacted immunohistochemically with S100 to enhance visualization of nerves. The study will also assess whether perineural invasion or its absence in MEC is associated with clinical outcome. Thirty-one cases of major and minor salivary gland MEC were reviewed for perineural invasion and compared to the perineural invasion status stated on the original pathology report when available (13/31). All H & E-stained slides were reviewed as well as S100-reacted sections of each case’s tissue blocks that contained tumor. Patient demographics and clinical outcome were collected from electronic medical records. Perineural invasion was identified in 23% (3/13) of tumors in the original reports, 13% (4/31) of the authors' re-review of the same slides, and 29% (9/31) when cases were reacted with S100. A positive relationship was seen between the discovery of perineural invasion on H & E-stained slides and a greater number of foci of perineural invasion. Perineural invasion and larger-diameter nerve involvement was significantly associated with death at 5-year follow-up. In conclusion, immunohistochemical enhancement improves the accuracy, ease and speed of perineural invasion determination. Perineural invasion is a significant factor in the decreased survival outcome of cases of MEC. These findings support continued inclusion of the presence or absence of perineural invasion as a grading parameter in MEC.
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Chankanka, Oitip. "Dietary intake and dental caries in children." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/653.
Full textAbstract:
Dental caries is a common childhood disease and important health problem in the United States and throughout the world. Most studies that have assessed risk factors for dental caries focused on non-modifiable risk factors such as previous caries experience and socioeconomic status. It is also important to investigate modifiable risk factors that can be used in developing guidelines for risk assessment and prevention. The present dissertation assessed mainly the associations between dental caries and modifiable factors, including dietary factors, water fluoride levels and toothbrushing frequency in children, while adjusting for non-modifiable factors. Data were obtained from subjects who were participants in the Iowa Fluoride Study. Dietary data were collected using 3-day dietary diaries from 1.5 months to 8.5 years and detailed questionnaires from 9 years to 13 years. Dental caries examinations were conducted at about 5, 9 and 13 years of age. There are three main analyses.
The first analysis assessed risk factors for a 4 group primary dentition caries experience variable: the caries-free (reference group), the d1, the d2+f, and the d1d2+f groups. The dietary consumption frequencies (from ages 3 to 5 years) for the children in the 4 caries groups were compared using multivariable multinomial regression analyses. Lower consumption frequency of milk at meals and greater consumption frequency of pre-sweetened cereal at meals significantly increased the likelihood of being in the d1 group. Greater consumption frequency of regular soda pop at snacks significantly increased the likelihood of being in the d1d2+f group. Greater consumption frequency of added sugars at snacks significantly increased chance to be in the d2+f group and the d1d2+f group.
The second manuscript assessed risk factors for new mixed dentition cavitated caries determined based on surface-specific transitions from the primary to mixed dentition exams on 16 teeth using logistic regression analysis. Greater consumption frequency of processed starch at snacks significantly increased the likelihood of having new cavitated caries (p = 0.04 for the model excluding previous caries experience).
The third manuscript used negative binomial regression with the Generalized Linear Mixed Models procedure to assess separately the longitudinal associations of 1) new non-cavitated caries and 2) new cavitated caries with modifiable risk factors. Surface-specific counts of new non-cavitated caries and cavitated caries at each of the primary, mixed and permanent dentition examinations were used as outcome variables. Greater consumption frequency of 100% juice was significantly associated with fewer non-cavitated and fewer cavitated caries surfaces.
In this study, some factors were associated with caries at one age only, while others were associated with caries across childhood. Consumption of foods or beverages at meals generally decreased their cariogenicity. Previous caries experience is strongly associated with other independent variables in the regression models that examined risk factors for new cavitated caries. Thus modifiable factors that usually have weaker associations with caries might not be retained in the models due to collinearity issues. Future researchers are encouraged to present results both ways so that scientific communities can best interpret the complex results. Also, repeated measures analysis might be more appropriate for variables that are common in all age groups, such as toothbrushing frequency and fluoride exposures. More studies of the complex relationships between diet and caries are needed, including additional studies that place more emphasis on investigation of modifiable risk factors for both non-cavitated and cavitated caries.
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Miller, Jeri L. "The influence of volume and viscosity on the distribution of anterior lingual force during the oral stage of swallowing /." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68222.
Full textAbstract:
The influence of bolus volume and viscosity on the distribution of anterior lingual force during the oral stage of swallowing was investigated using a new force transducer technology. The maximum force amplitudes from five normal adults were measured at anterior, right and left lateral tongue margins during ten volitional swallows of 5-, 10-, and 20-ml volumes of water, applesauce, and pudding. Results indicated significant increases in peak force amplitude as viscosity increased. Volume did not significantly influence maximum lingual force amplitudes. Individual subjects demonstrated consistent patterns of asymmetrical force distribution across the lingual margins tested. The results suggest bolus-specific properties influence the mechanics of oral stage lingual functioning. This finding has important clinical implications in the assessment and treatment of dysphagic individuals. Applications of the force transducer array in future research are addressed.
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Orgill, Joshua J. "The impact of luminance on localizing the inferior alveolar canal on cone beam computed tomography." Thesis, University of Iowa, 2019. https://ir.uiowa.edu/etd/6824.
Full textAbstract:
Introduction: The use of CBCT to visualize the relationship between the inferior alveolar canal and the mandibular third molar roots continues to grow as it is becoming the standard of care. It becomes important to understand the impact that luminance, one of the factors that affects the viewing conditions of digital images, has on appropriately assessing the third molar-canal relationship. To date, no study has assessed the impact of luminance on visualizing anatomic structures on CBCT. The aim of this study is to determine if there is a difference in the ability to appropriately assess the root development and the third molar-canal relationship on a medical grade monitor with four different luminance settings on CBCT.
Materials and methods: 285 scans were randomized and evaluated by three calibrated and masked evaluators. The evaluations were completed on a Barco MDNC-3321 Nio Color 3MP monitor (Kortrijk, Belgium) monitor at four different luminance settings; 200 cd/m2, 300 cd/m2, 400 cd/m2, and 500 cd/m2. The gold standard was established by two board-certified oral and maxillofacial radiologists. All evaluations were performed in a controlled subdued environment lighting of less than 15 lux. There was a washout period of at least one week between each of the four evaluations by an observer.
Results: The accuracy of two of the three evaluators was substantial to almost perfect independent of luminance. None of these assessments showed any statistical significance (P = 0.05). The accuracy of one evaluator was moderate to almost perfect for all evaluations with one assessment of one canal showing statistical significance (P = 0.05).
Conclusion: There is no difference in the ability to appropriately assess the third molar canal relationship or the root development of third molars on a medical grade monitor at luminance settings between the range of 200 cd/m2 and 500 cd/m2 when viewed in a dimly lit room.
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Sousa, Melo Saulo Leonardo. "The impact on diagnostic yield of the scan mode of cone beam CT images in artificial external root resorption." Thesis, University of Iowa, 2016. https://ir.uiowa.edu/etd/6292.
Full textAbstract:
Introduction: Root resorption is an undesired but frequent side effect of orthodontic treatment. Several studies have already aimed to evaluate the performance of CBCT on this topic. However, none have addressed the peculiarities of the most common daily orthodontic scenario. The aim of the study was to evaluate the influence of CBCT scans on the diagnosis of artificial external root resorption in the apical third of anterior teeth.
Materials and methods: One hundred extracted human anterior teeth were randomly assigned to 2 uneven groups (51 as the control and 49 as the experimental group). A limited area of the apical third of the root of the teeth of the experimental group was selected and a buffer solution was used to induce tooth subsurface demineralization. Before CBCT image acquisition, each tooth was coated with an approximately 0.3 mm thick layer of utility wax to simulate the radiographic appearance of the periodontal space and placed into an empty mandibular anterior socket of a partially edentulous dry human mandible. The mandible was placed into a polystyrene box filled with water prior to the CBCT examination to simulate soft-tissue attenuation and scattering. The CBCT images were obtained on an i-CAT unit (i-CAT Next Generation, Imaging Sciences International, Hatfield, PA) according to three protocols: (I) half scan (180°), 0.40 mm voxel size; (II) full scan (360°), 0.40 mm voxel size; and (III) full scan (360°), 0.125 mm voxel size. The 300 resultant CBCT DICOM volumes were imported into InVivo software (InVivo5, Anatomage, San Jose, CA) for evaluation by three blinded, previously calibrated observers using a five-point confidence rating scale. Cohen’s kappa was used to calculate observers’ agreement. The diagnostic values of sensitivity (Sn), specificity (Sp) and accuracy (Ac) were performed by pooling observer responses for every image modality. Receiver operating characteristic (ROC) were built and the areas under the curve (AUC) were calculated. The Sn, Sp and Ac values were compared by Cochran’s Q test. The AUC values were compared by Mann-Whitney U test.
Results: The observers’ agreement ranged from 0.63 to 0.71, which was interpreted as a substantial agreement. Protocol III (0.125 mm voxel size) displayed the highest Sn (81.63 %), Ac (80.67%) and AUC (0.807). There were statistically significant differences between protocol III and the other two protocols (p < 0.001). The specificity of protocol I (84.97 %) was greater than that of protocols II (69.93 %) and III (79.74 %); however statistically significant difference was only found between protocols I and II (p = 0.005).
Conclusion: Although there was no difference in accuracy between the degrees of rotation (half and full scan) within the same voxel size (0.4 mm), there was a considerable difference between those and the smallest voxel size (0.125 mm). In fact, it may be suggested that a more dedicated, high resolution scan should be acquired when one intends to investigate the early stage of external root resorption during orthodontic treatment.
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Khng, Kwang Yong Kelvin. "An in vitro evaluation of the marginal integrity of CAD/CAM interim crowns compared to conventional interim resin crowns." Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/4863.
Full textAbstract:
CAD/CAM technology had evolved extensively from the time when it was first used clinically in the 1980s. Today, CAD/CAM technology can be used to fabricate crowns, design and mill fixed partial denture frameworks, set teeth and fabricate complete dentures as well as to mill interim restorations. An extensive literature review found many research studies on the evaluation of the accuracy of the CAD/CAM ceramic crowns as compared to other ceramic crowns but little research had been done to evaluate the accuracy of interim restorations. This article describes the method in which CAD/CAM as well as conventional interim crowns were fabricated, cemented onto their dies, dye stained, thermocycled as well as sectioned with their marginal discrepancies investigated.
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Oweis, Reem. "Associations between fluoride intakes, bone outcomes and dental fluorosis." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6239.
Full textAbstract:
These PhD projects represent secondary analyses of data from the ongoing Iowa Fluoride Study (IFS)/Iowa Bone Development Study (IBDS). The aim of this dissertation was to explore the associations between period-specific and cumulative fluoride intakes from birth to age 17, and from birth to age 19 years and bone measures of participants. Also, this dissertation looked into the associations between the clinical presence of dental fluorosis and bone outcomes.
Participants have been participating in the IBDS that grew out of the IFS, which is a longitudinal investigation of dietary and non-dietary fluoride exposures, dental fluorosis and dental caries. IFS participants were recruited during 1992-95 from 8 hospital postpartum wards in Iowa, and detailed questionnaires were sent every 1.5-6 months. Data on intakes from water, other beverages, selected foods, dietary fluoride supplements and dentifrice were collected from the questionnaires, and, in combination with water and beverage fluoride levels, combined fluoride was estimated.
For the first dissertation project, the association between fluoride intake and peripheral quantitative computed tomography (pQCT)-derived bone outcomes at age 17 were assessed. Participants underwent pQCT of the radius and tibia (XCT-2000) at age 17 years. pQCT results of trabecular bone mineral density (BMD) and bone mineral content (BMC), cortical BMD and BMC, and compression and torsion strength were related to fluoride intake through bivariate and multivariable analyses, adjusting for height, weight, years since peak height velocity, average daily time spent in moderate-to-vigorous intensity physical activity, daily calcium intake, and daily protein intake. P-values < 0.01 were considered statistically significant rather than p< 0.05 due to multiple hypothesis tests. The mean daily fluoride intake estimated by area-under-the-curve (AUC) from birth to 17 years was 0.79 mg (SD = 0.32) for males and 0.70 mg (SD = 0.25) for females. Spearman correlation coefficients between daily fluoride intake and pQCT bone measures were weak (for females r= -0.01 to 0.15 for radius bone outcomes and -0.001 to 0.23 for tibia bone outcomes; for males r= 0.03 to 0.24 for radius bone outcomes and -0.008 to 0.27 for tibia bone outcomes). In sex-specific linear regression analyses for females, partially-adjusted for height, weight, and years since peak height velocity, statistically significant negative associations were detected between all radial bone outcomes and period-specific fluoride intake from 0-8.5 years. Significant positive associations were detected for females between period-specific fluoride intakes from 14-17 years and all tibia bone outcomes, and between period-specific fluoride intakes from 14-17 years and all radius and tibia bone outcomes for males. In the fully-adjusted models, which also included physical activity, protein intake and calcium intake, statistically suggestive negative associations were detected for females during the early fluoride intake period from 0 to 8.5 years and radial cortical bone content and torsion bone strength. A statistically suggestive positive association was found between period-specific fluoride intake from 8.5 to 14 years and torsion bone strength (pSSI) (p< 0.05) for females. For males, statistically significant positive associations were detected between fluoride intake for the period from 14 to 17 years and cortical content and torsion strength (pSSI) at the 0.01 level.
The second project examined the associations between period-specific and cumulative fluoride intakes from birth to age 19 years and MDCT-derived bone outcomes at age 19. Age 19 MDCT-derived trabecular and cortical bone micro-architecture scans were acquired at the University of Iowa Comprehensive Lung Imaging Center. MDCT results of the trabecular (volumetric bone mineral density (vBMD), transpose bone mineral density (tBMD), plate trabecula bone mineral density (pBMD), plate width (TS-PW), trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp), trabecular network area (Tb.NA)) and cortical (cortical bone porosity (Cb.Poro), cortical thickness (Cb.Th)) bone were related to fluoride intake through bivariate and multivariable analyses, adjusting for height, weight, years since peak height velocity, average daily time spent in moderate-to-vigorous intensity physical activity, Healthy Eating Index (HEI) score, calcium intake and protein intake. P-values < 0.01 were considered statistically significant rather than p< 0.05 due to multiple hypothesis tests. The mean daily fluoride intake estimated by area-under-the-curve (AUC) from birth to 19 years was 0.81 mg (SD = 0.33) for males and 0.69 mg (SD = 0.27) for females. Spearman correlation coefficients between daily fluoride intake and MDCT bone measures were weak (for females r= -0.001 to 0.20 for trabecular bone outcomes and -0.01 to 0.02 for cortical bone outcomes; for males r= -0.003 to 0.16 for trabecular bone outcomes and -0.09 to -0.02 for cortical bone outcomes). In sex-specific partially-adjusted regression analysis adjusted for height, weight, and years since peak height velocity, no statistically significant associations were found for females or males. In the fully-adjusted models, which also included physical activity, HEI score, and protein and calcium intakes, no statistically significant associations were found for either females or males.
The third project explored the associations between dental fluorosis score at age 8 and DXA-derived bone outcomes at age 5. DXA bone assessments of the whole body, proximal femur (hip), and lumbar spine were performed at The University of Iowa in the Clinical Research Center (Hologic QDR-2000 DXA unit). The dental fluorosis score was defined as the proportion of zones with definitive or severe fluorosis per person. In the unadjusted associations between bone outcomes and dental fluorosis score, no statistically significant associations were detected for females at the 0.05 level. For males, a statistically significant negative association was found between hip BMD and dental fluorosis score. Sex-specific partial correlation coefficients were estimated between DXA-derived bone outcomes and dental fluorosis score adjusted for height, weight, physical activity, calcium intake and fluoride intake. No statistically significant associations were found for females. For males, a statistically significant negative association was detected between dental fluorosis score and hip BMD.
The findings of this dissertation show that life-long intakes from combined sources for adolescents and young adults living in fluoridated areas in the United States were weakly associated with bone measures at age 17 and 19. Furthermore, it was shown that bone outcomes can’t be predicted by the score of dental fluorosis.
Fluoride is a mineral that plays an important role in the mineralization of bone and teeth, as well as in dental caries prevention. Numerous professional health organizations endorse the adjusted fluoridation of public water supplies for caries prevention. Results from this dissertation will also help in supporting additional efforts to promote water fluoridation and expand its use, as this dissertation’s outcomes did not demonstrate adverse outcomes related to bone.
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Garaicoa, Pazmino Jorge Luis. "Minimal inhibitory concentration of antimicrobial and antifungal agents in denture adhesive material against Candida albicans." Thesis, University of Iowa, 2014. https://ir.uiowa.edu/etd/1458.
Full textAbstract:
Approximately 26% of the U.S. population between the ages of 65 and 74 years are completely edentulous. Of the different proposed predictors and risk factors, low income and education levels have the highest correlation with tooth loss. While the incidence of complete edentulism in the United States has progressively declined over the past decade, the continued growth of the population strongly suggests that edentulism prevalence will likely remain constant or increase over the next few decades. In patients wearing complete prosthetic appliances, several post-treatment complications may arise, including denture associated Candida species infections and mucosal stomatitis. These type of fungal infections are associated with patient-reported symptoms (e.g. pain or discomfort) and may impede normal oral function. In this study the activity of 11 (antimicrobial and/or antifungal) agents in a dental adhesive carrier against two strains of C. albicans was assessed. In conventional minimal inhibitory concentration (MIC) assays, C. albicans were resistant to histatin 5 and lactoferricin B, yet very susceptible to SMAP28; susceptible to long chain bases sphingosine, dihydrosphingosine, and phytosphingosine; and susceptible to anti-fungal agents amphotericin B, chlorhexidine dihydrochloride, chlorhexidine gluconate, fluconazole, and nystatin. However, in 1% dental adhesive (final concentration) C. albicans were resistant to histatin 5, lactoferricin B, SMAP28, sphingosine, dihydrosphingosine, and phytosphingosine suggesting that the components in denture adhesive may inactivate local innate immune factors in the oral cavity possibly predisposing users to fungal infections in relation to their dental prostheses. In MIC assays in 1% dental adhesive (final concentration) C. albicans were susceptible (p value < 0.05) to amphotericin B, chlorhexidine, dihydrochloride, chlorhexidine gluconate, fluconazole, and nystatin strongly suggesting that these anti-fungal agents could be candidates for inclusion in denture adhesive formulations, and also be used as a prescribed topical treatment in individuals with fungal infections of the oral mucosa.
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Kateeb, Elham Talib. "Factors related to the use of atraumatic restorative treatment (ART) in pre and post-pediatric dentistry programs and in pediatric dentistry practices in the US." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/2912.
Full textAbstract:
Dental Caries is still considered one of the most prevalent chronic diseases that affect children in the US. Access to oral care problems could be due to the limited availability of services or unwillingness of people to seek services. As a proposed solution to those challenges, Atraumatic Restorative Technique (ART) was developed in the 1980s as an affordable, patient friendly caries management procedure that does not need extensive operator training or special skills. ART was originally developed to be conducted in field settings; however, after initial evidence of effectiveness, the World Health Organization (WHO) and the International Dental Federation (FDI) promoted the use of ART in modern clinical settings worldwide. In the US, the practice of ART is not believed to be widely used. This may be a result of little attention given to (ART) in dental education and advanced training.
This dissertation is comprised of three separate studies that investigated the extent and the factors related to the didactic and clinical instruction on ART in US pre- and post-doctoral pediatric dentistry programs and the factors related to the willingness of pediatric dentists to use ART with their child patients. survey post-doctoral pediatric dentistry program directors and pre-doctoral pediatric dentistry program directors. In study III a different instrument was used to survey pediatric dentists in the US. The survey instruments were tested for content and face validity by cognitive analysis interviews and pilot testing. Using web-based survey methodology, two questionnaires were sent out in May 2010 to investigate self-reported use of ART in educational training institutes (study I and II) and in April 2011, a third questionnaire was sent to a random national sample of pediatric dentists (study III). Using a conjoint design, the third questionnaire asked pediatric dentists to rate their willingness to use ART for 9 patients' scenarios. Eighty eight percent of Pediatric Dentistry Residency programs and 66 % of pre-doctoral pediatric dentistry programs in the US provided clinical training on ART; however only 30% of post-doctoral programs and 14 % of pre-doctoral programs used ART "Very Often/ Often" as a caries management technique for their pediatric patients. Pediatric Dentistry residency programs and pre-doctoral pediatric dentistry programs used ART mainly in primary, anterior, single surface cavities and as an interim treatment. Attitudes toward ART alone and after controlling for other variables explained 35% of the level of training on ART in post- doctoral program and 23% in pre-doctoral pediatric dentistry programs. For study III, conjoint analysis showed that being very young and/or uncooperative were the most important reasons practitioners reported a higher likelihood of using ART. Although insurance coverage was the least important factor overall, not having any insurance was identified as an additional important factor in decisions to use ART. Collectively, our results suggest that that the use of ART is not widespread in the US. In addition, ART is viewed by some as a sub optimum treatment and needs to be modified to conform to the US standards of care. On the other hand, educators and pediatric dentists who had positive views of ART thought it could be a valuable treatment for very young, uncooperative children and children with no insurance.
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Abuhammoud, Salahaldeen Mohammad. "Knowledge and practice of implant dentistry among University of Iowa College of Dentistry alumni." Thesis, University of Iowa, 2018. https://ir.uiowa.edu/etd/3235.
Full textAbstract:
Objective: The objective of this study was to measure and assess the implant education received by graduates from the University of Iowa College of Dentistry and Dental Clinics. This study measured the self-reported competency levels of dental practitioners with regards to providing and maintaining dental implants as treatment modalities to their patients. The study assessed dental graduates’ willingness to practice and perform dental implant procedures, including both surgical and prosthetic treatments. Additionally, the study identifies challenges that face practicing dentists treating patients with dental implants and identifies the preferred way practitioners seek future training after completing dental school.
Methods: A 36-item electronic survey was created and distributed to 737 dentists who graduated from the University of Iowa College of Dentistry and Dental Clinics. Dentists’ demographics, practice characteristics, and detailed self-reported competency in implant dentistry were collected. Statistical analysis of the responses consisted of descriptive statistics and bivariate analysis, and nonparametric Wilcoxon rank-sum test and Spearman’s rank correlation test along with a chi-square test were used for detecting the differences, correlations and associations under different conditions.
Results: 154 dentists completed the survey (21% response rate), while only 143 subjects who fulfilled the inclusion criteria were included for the statistical analysis. The survey consisted mostly of males (56.6%). The mean age of respondents was 34.2 years old with a mean practice time of 6.2 years. Of the responding dentists, 21.7% completed a postgraduate training program and 51% of the respondents were in group practice. 66% of the respondents practice in the Midwest region of the US and 71.3% of the respondents took continuing educational courses in implant dentistry and the mean cumulative hours of CE courses in implant dentistry was 33.8 hours. The mean average of implant restorations provided per year was 11.7 and the mean average of implant placements per year was 19.6. There was a significant correlation between cumulative hours of Continuing Education courses and number of implant units on average placed or restored. 64.3% of the dentists are not satisfied with the implant education given at the dental student level. 95.8% of the dentists reported that dental school training is not adequate to surgically place dental implants in their practice. Only 32.4% reported that dental school training was not adequate to restore dental implants in their practice. The preferred way to receive additional training about dental implants is short-term CE courses and workshop courses conducted by implant companies. 23.6% of the dentists reported they are competent at surgically placing dental implants in their practice. 79.1% reported they are competent at restoring dental implants in the dental office. Only 28.4% reported that they feel dental implants are more difficult than other dental treatments.
Conclusions: Graduate dentists from the University of Iowa are not expected to be competent in all components of implant dentistry without further postgraduate training. Respondents stated that their dental school training in surgical placement of implants was inadequate. To build upon their dental school training, the two main preferred education pathways as reported by respondents were short-term continuing education courses and workshops courses conducted by implant companies.
Within the parameters of this study, we can conclude the following:
1.Age, GPA, number of CE hours in dental implant therapy, specialty status, and time since graduation did not influence undergraduate education satisfaction in dental implant therapy.
2.There is a positive correlation between the number of CE course hours and the number of implant units restored or placed by general dentists.
3.Male dentists, those who practice in group practice settings, and those who have graduated six or more years ago reported a greater number of CE course hours in dental implant therapy.
4.Those who graduated with GPAs less than or equal to 3.4, general dentists, and those who enrolled in a high number of CE courses were more confident in restoring dental implants.
5.Those who graduated with a GPA greater than or equal to 3.5, specialist dentists, and those who enrolled in a high number of CE courses were more confident in surgically placing dental implants.
6.Males, general dentists, those who practice in a group practice setting, and those who graduated six years or more ago restored more implants on average per year.
7.Males, specialist dentists, those who practice outside the Midwest US, and those who graduated six years or more ago surgically place more implants on average per year.
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Walters, Jaco. "Diagnostic accuracy of maxillary periapical pathology perforating the sinus floor: a comparison of pantomograph and CBCT images." University of Western Cape, 2020. http://hdl.handle.net/11394/7349.
Full textAbstract:
>Magister Scientiae - MScPeriapical lesions are fairly common pathology associated with the apex of a non-vital tooth. Some chronic lesions develop without an acute phase with no recollection of previous symptoms. It is known that maxillary odontogenic infections can breach the sinus floor with succeeding complications. Pantomography, a widespread conventional radiographic technique, provides a generalized view of the maxillofacial region. Advanced modalities like CBCT may facilitate in navigating complex anatomy, which would otherwise be obscured.
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Osterne, Rafael Lima Verde. "âEstudo epidemiolÃgico de lesÃes orais em laboratÃrios de anÃtomo patologia na cidade de Fortaleza-Ceâ." Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=2994.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorA boca pode ser acometida por doenÃas, variando de alteraÃÃes de desenvolvimento à neoplasias malignas agressivas e metastatizantes. O conhecimento destas condiÃÃes auxilia no diagnÃstico diferencial realizado pelo clÃnico. Este trabalho tem como objetivo realizar uma anÃlise epidemiolÃgica das lesÃes de cavidade oral em cinco laboratÃrios de anÃtomo patologia da cidade de Fortaleza, CearÃ, Brasil. MÃtodos: Coleta de dados a partir de laudos histopatolÃgicos de lesÃes orais, no perÃodo de 2001 a 2005, oriundos de cinco laboratÃrios, de anatomia patolÃgica, pÃblicos e privados. As variÃveis utilizadas foram sexo, idade, raÃa, localizaÃÃo anatÃmica e laudo histopatolÃgico. As lesÃes analisadas foram agrupadas em nÃo-neoplÃsicas, neoplÃsicas e laudos descritivos. Resultados: No perÃodo analisado, foram coletadas 6231 lesÃes orais, das quais 41,41% oriundas de laboratÃrios particulares e 58,59% de laboratÃrios pÃblicos. O sexo feminino foi o mais acometido, com proporÃÃo homem:mulher de 1:1,68. As lesÃes ocorreram em uma ampla faixa etÃria, variando de 0 a 100 anos, com pico de incidÃncia entre 31 e 60 anos. As lesÃes nÃo-neoplÃsicas representaram 64,89% dos casos, com as lesÃes inflamatÃrias/reativas sendo as mais prevalentes, seguidas pelas lesÃes inflamatÃrias de glÃndula salivar, cistos e hiperplasias epiteliais sem atipias. As neoplasias representaram 30,80% dos casos, das quais 59,52% eram benignas, 32,45% malignas e 8,03% eram lesÃes prÃ-malignas. A hiperplasia fibroepitelial foi a lesÃo mais prevalente em todo o estudo e o carcinoma de cÃlulas escamosas, a neoplasia maligna mais comum, com 23,14% e 8,52% respectivamente ConclusÃo: As lesÃes foram mais comuns no sexo feminino, na faixa etÃria economicamente ativa, representadas principalmente por lesÃes inflamatÃrias/reativas. Apesar da alta ocorrÃncia de lesÃes inflamatÃrias/reativas neste estudo, a prevalÃncia de lesÃes malignas foi significativa, demonstrando a necessidade do conhecimento destas lesÃes pelo cirurgiÃo dentista e a criaÃÃo de polÃticas pÃblicas que enfatizem a prevenÃÃo e o diagnÃstico precoce das mesmas
A wide range of diseases can affect the oral cavity, from developmental defects to metastasizing malignant neoplasms. The knowledge on Oral Pathologies`s prevalence helps the clinician making differential diagnosis. The aim of this study was to perform an epidemiological survey of oral lesions in five anatomopathological laboratories in Fortaleza, CearÃ, Brazil. Methods: The sample was obtained from histopathology reports of oral lesions diagnosed between the years of 2001 to 2005 in five anatomopathological laboratories. Data regarding sex, race, age, anatomical site and histopathological diagnosis were registered. Lesions were categorized in non-neoplastic, neoplastic and descritive reports. Results: During the five-year period, 6231 oral lesions reports were collected, 41,41% from private laboratories and 58,59% from public laboratories. Female were more affected, with a male:female ratio of 1:1,68. Lesions occurred in a wide age range, varying from 0 to 100 years old, with an incidence peak between 31 to 60 years. Non-neoplastic lesions represented 64,89% of cases, with inflammatory/reactive lesions being the most prevalent group, followed by inflammatory lesions of salivary glands, cysts and non-atypical epithelial hyperplasia. Neoplastic lesion represented 30,80% of cases, 59,52% benign, 32,45% malignant and 8,03% pre-malignant lesions. Fibroepithelial hyperplasia was the most common lesion in this study and squamous cell carcinoma was the most prevalent malignant neoplasm, with 23,14% and 8,52%, respectively. Conclusions: Oral lesions were more common among femaleâs reports, in economically active age, mainly represented by inflammatory/reactive lesion. Although, the occurrence of inflammatory/reactive lesions was high, the prevalence of malignant neoplastic and pre-malignant lesion was significant. There dental surgeon must know about the occurrence of such lesions, and public health politics for prevention and early diagnose must be enfasized
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Tchoungui, Oyono Lilly. "The norming of the "Evaluation du language Oral" and the prevalence of speech and language disorders in pre-school aged children from Yaoundé (Cameroon)." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/20772.
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Research suggests that speech and language disorders are among the most prevalent childhood disabilities in many countries. Identification and intervention for children with communication disorders are sought at an early stage, to avoid the consequences of untreated childhood speech and language problems that can lead to academic underachievement and even persist into adulthood. However, no study has been reported on the prevalence of speech and language disorders in the general population in Cameroon. Despite the published literature on the national burden of disease suggesting that a significant number of Cameroonian children might have limitations in their speech and language abilities. This descriptive cross-sectional study aimed to determine the prevalence of speech and language disorders, specifically, articulation, expressive language, receptive language, fluency and voice disorders; in a representative sample of French-speaking preschool children in Yaoundé, the capital city of Cameroon. A total of 460 children aged 3 to 5 years were recruited from the seven communes of Yaoundé city using multi-stage random sampling method. As there was no validated speech and language test available for the population of French-speaking preschool aged children in Cameroon, this study has contributed in its first part, to provide norms on three subtests of a standardised French speech and language test, the 'Evaluation du Langage Oral' (ELO) for this population. These norms can be used for clinical practice and research purpose in Cameroon. In order to determine the prevalence of articulation, expressive and receptive language disorders, a cut-off of two Standard Deviations (SD) below the normative mean was applied. The identification of fluency and voice disorders among participants was based on clinical judgement. All the assessments were performed by the researcher who is a qualified speech-language therapist with experience of practice in Cameroon. The findings indicated that the prevalence of articulation disorders was 3.6%, expressive language disorders was 1.3%, receptive language disorders was 3%, fluency disorders was 8.4% and voice disorders was 3.6%. The overall prevalence of speech disorders was 14.7%, language disorders 4.3% and speech and language disorders 17.1%. There was no significant difference in the prevalence of speech and language disorders according to gender. The prevalence of speech and language disorders in the present study was higher than that of many previous investigations conducted in other countries. The findings of this research reveals and emphasises the urgent need to build a strategy to develop speech and language services to serve the Cameroonian population.
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Boggs, Teresa. "Book Reading as a Means for Increasing Oral Language Skills." Digital Commons @ East Tennessee State University, 2013. https://dc.etsu.edu/etsu-works/1508.
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Pham, Christopher K. "The Study of the Regulon of OxyR in Escherichia coli and Porphyromonas gingivalis." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4155.
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The facultative anaerobe, Escherichia coli and the obligate anaerobe, Porphyromonas gingivalis are two bacteria that reside in our body. Although they reside in separate environments, they are both subject to hydrogen peroxide stress and have mechanisms to regulate the stress. OxyR is the primary transcriptional regulator/sensor of oxidative stress response caused by hydrogen peroxide. OxyR in P. gingivalis is not well-characterized compared to OxyR in E. coli. We sought to characterize and compare the two forms of OxyR in order to gain a better understanding of the protein. We determined the oligomeric state of both proteins: primarily a tetramer for E. coli and primarily a tetramer for P. gingivalis OxyR.. We demonstrated DNA binding with E. coli OxyR, indicating purification of the functional form of E. coli OxyR.Through pulldown assays we discovered potential novel binding targets, mobB for E. coli OxyR and PG1209 for P. gingivalis OxyR. Many of the other targets corresponded to intergenic regions within genes, which may pertain to small RNAs or small proteins. These results show that OxyR in E. coli and P. gingivalis has novel function and properties indicating an expanded role in addition to the well-characterized oxidative stress response.
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Marinis, Aristotelis. "Fracture toughness of yttrium stabilized zirconia sintered in conventional and microwave ovens." Thesis, University of Iowa, 2011. https://ir.uiowa.edu/etd/1017.
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Phattarataratip, Ekarat. "The role of salivary antimicrobial peptides in shaping Streptococcus mutans ecology." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/724.
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Antimicrobial peptides are among the repertoire of host innate immune defenses. In mucosal immunity, the health-disease balance can be greatly modulated by the interplay between host immune factors and colonized microflora. Microbial ecology within dental plaque is constantly shaped by environmental factors present within the oral cavity. Several antimicrobial peptides are detected in saliva and their bactericidal activities against oral bacteria, including Streptococcus mutans, the primary etiologic agent of dental caries, have been clearly demonstrated. However, the role of these antimicrobial peptides in S .mutans ecology and host caries experience is not well-defined. We hypothesized that various strains of S. mutans possess different inherent susceptibility/resistance profiles to host salivary antimicrobial peptides and that host-specific quantities of these peptides may influence plaque colonization by particular S. mutans strains.
S. mutans strains from subjects with variable caries experience were tested for susceptibility to a panel of antimicrobial peptides, including HNP-1-3, HBD-2-3 and LL-37, revealing that the susceptibilities of S. mutans to these peptides were strain-specific. S. mutans strains from high caries subjects showed greater resistance to these peptides at varying concentrations than those from caries-free subjects. In addition, when combinations of these peptides were tested, they showed either additive or synergistic interaction against S. mutans.
Determinations of the salivary levels of these peptides showed that their concentrations were highly variable among subjects with no correlation to host caries experience. However, positive relationships between the salivary concentrations of HNP-1-3 and MS in dental plaque were found. Additionally, the levels of a number of these peptides in saliva appeared to be positively correlated within an individual. An analysis of the salivary peptide concentrations and the susceptibility profiles of S. mutans strains showed that S. mutans strains obtained from subjects with higher concentration of HNP-1-3 in saliva appeared to be more resistant to HNP-1.
Collectively, our findings showed that salivary antimicrobial peptides affect S. mutans ecology by restricting the overall growth of this bacterium within the oral cavity and that their activity may help select resistant strains of S. mutans to colonize within dental plaque. The relative ability of S. mutans to resist host salivary antimicrobial peptides may be considered a potential virulence factor for this species.
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Smith, Katherine Mary. "Body fat indices and biomarkers of inflammation in saliva: a cross-sectional analysis with implications for obesity and peri-implant oral health." Thesis, University of Iowa, 2015. https://ir.uiowa.edu/etd/6645.
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The prevalence of obesity is continually rising in developed countries like the United States. Based on the association between periodontitis and obesity and the relationship between periodontitis and peri-implantitis, it is important to understand the implications of obesity on peri-implant health. A potential relationship between obesity and peri-implant health has practical, biological and financial implications.
The primary objective of this study was to determine the association between obesity as measured by the body fat indices (body mass index (BMI), waist circumference (WC), and body fat percent (fat %)) and the levels of inflammatory biomarkers in saliva. In addition, this study explored the correlations between the levels of these biomarkers in saliva versus their corresponding levels in peri-implant sulcular fluid (PISF) and gingival crevicular fluid (GCF) samples collected from the same subjects.
Periodontal maintenance patients (N=73) were enrolled in this cross-sectional study. Anthropometric measurements (BMI, WC, and body fat %), intraoral assessment (full mouth plaque index, periodontal, and peri-implant comprehensive examinations) and unstimulated whole saliva samples were collected from the subjects. GCF and PISF were also collected. Levels of interleukin (IL)-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, IL-12(p40), IL-17α, tumor necrosis factor (TNF)-α, osteoprotegerin (OPG), letpin and C-reactive protein (CRP) in saliva, GCF and PISF were analyzed using multiplex immunoassays. Statistical analyses were performed to explore the correlations of interest.
Data from 63 subjects were included in the analysis. No statistically significant correlations were noted between any of the body fat indices and any of the biomarkers measured in saliva (p>0.05 in all instances). A significant positive correlation was noted between salivary and GCF levels of IL-1α (r=0.29, p=0.0232), IL-8 (r=0.29, p=0.0207) and between saliva and PISF levels of leptin (r=0.32, p=0.0284). The employed linear model also revealed the significant impact of tooth brushing frequency on the salivary levels of IL-1α, IL-1β and TNF-α (p<0.05). Based on this cross-sectional study of 63 patients, I conclude that there was no statistically significant correlation noted between salivary inflammatory biomarkers and any of the obesity measures. However, the levels of key inflammatory markers in saliva strongly correlated with their corresponding levels in GCF/PISF. In addition, frequency of tooth brushing was also related to levels of certain biomarkers in GCF/PISF.
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Morarend, Quinn Alan. "The use of RESPeRATE™ to reduce dental anxiety." Thesis, University of Iowa, 2009. https://ir.uiowa.edu/etd/410.
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Background
Anxiety experienced by individuals visiting the dental office to receive treatment is prevalent in the population. The clinical manifestation of these anxieties is considerable; it is estimated that approximately between 14 and 30 million people in the United States do not seek routine dental care due to dental anxiety. Dentists and other scientists have explored many techniques and procedures in attempts to ameliorate these anxieties and improve patient care. Biofeedback is a process that involves measuring a person's specific bodily functions such as blood pressure, heart rate, skin temperature, muscle tension, or breathing rate, and conveying the information to the patient in real-time. This raises the patient's awareness and therefore the possibility of conscious control of those functions. Evidence has shown biofeedback to be a useful modality of treatment for numerous conditions associated with anxiety. Anxiety has been shown to up-regulate the sympathetic nervous system. When the sympathetic nervous system is up-regulated, the pain threshold is decreased, and physiologic parameters of anxiety are manifested in the patient. This physiological phenomenon is well understood and demonstrates that, with anxiety, the individual will have a decreased pain threshold (i.e., greater response to noxious or painful stimuli). The purpose of the current pilot study is to investigate the use of a novel biofeedback system (RESPeRATE™) to reduce patients' pre-operative general anxiety levels and subsequently the pain associated with dental injections.
Methods
Eighty-one subjects participated in this randomized controlled study. Forty subjects were in the experimental group and forty-one subjects were in the control group. All subjects were asked to fill out a pre-injection survey (Dental Injection Sensitivity Survey - DISS), measuring baseline anxiety levels. Subjects in the experimental group used a biofeedback technique, while subjects in the control group were not exposed to any biofeedback. All participants then received an inferior alveolar local anesthetic injection. Subjects in both groups were then given a post-injection survey (measuring anxiety levels), and filled out a Visual Analog Scale (VAS). The VAS was designed to measure the subjects' perception of pain of the injection, the overall injection experience, and anticipatory anxiety for future injections.
Results
The results of the study demonstrated that there was no significant difference between the treatment group and the control group with respect to any of the pre/post-operative anxiety measures as recorded by the DISS. This study did demonstrate that with the use of the RESPeRATE™ device there was a significant difference in the overall injection experience between the experimental group and the control group (p=0.013), as measured by the VAS. A trend towards improved responses for the experimental group was noted with respect to both level of discomfort and ratings of future nervousness; these results did not reach a statically significance of p<.05.
Conclusions
Future studies and power calculation will be more specific towards the RESPeRATE™ in a dental setting, and lead to more accurate approximations on the number of subjects needed to determine whether the difference was due to chance or due to the treatment modality. It appears that this novel pilot study was underpowered. It would also be feasible to apply the technology to other areas in dentistry where anxiety and sympathetic up-regulation are etiologic components. Areas of future studies may include temporomandibular joint dysfunction, orofacial pain, periodontal disease, and wound healing.
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Mehalick, Leslie Ann. "Sphingoid bases induce dose-dependent cytotoxicity and cytokine responses in human myeloid dendritic cells." Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/2579.
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Sphingoid bases (sphingosine, dihydrosphingosine and phytosphingosine) have been recently found in the oral cavity where they may serve to fortify innate immunity against commensals and periodontal pathogens. In fact, sphingoid bases have potent antimicrobial activity against Gram- positive and Gram- negative bacteria including oral pathogens like Porphyromonas gingivalis. It is not known whether these lipids are cytotoxic or alter the chemokine and cytokine responses of human dendritic cells, a finding important to their future potential as a therapeutic for treatment of periodontal disease.
Objectives: The objective of this study was to determine the effects of sphingoid bases on the cytotoxicity and cytokine responses of human myeloid dendritic cells.
Methods: Dendritic cells were treated with sphingoid bases (0.2-80.0 μM) for 16 hours in the presence or absence of 0.02 μM hemagglutinin B, a nonfimbrial adhesin of P. gingivalis used as a pro-inflammatory stimulus. The cytotoxicity of the inocula and its ability to induce the production of chemokines and pro-inflammatory cytokines was determined after 16 hours.
Results: Higher concentrations of sphingoid bases were cytotoxic (e.g., 40.0-80.0 μM), but physiologic concentrations of sphingoid bases (e.g., 0.2-20.0 μM) were not. At 5, 10, or 20 μM, sphingosine did not enhance or attenuate any HagB-induced IL-8, GM-CSF, MIP-1α, MIP-1β, or TNFα response of human myeloid dendritic cells. At 5 or 10 μM, neither phytosphingosine nor dihydrosphingosine enhanced or attenuated any HagB- induced IL-8, GM-CSF, MIP-1α, MIP-1β, or TNFα response of human myeloid dendritic cells.
Conclusion: Sphingoid bases exhibit dose-dependent cytotoxicity and cytokine responses against human myeloid dendritic cells. But at physiologic concentrations sphingoid bases appear to be safe and efficacious at the doses needed to prevent or treat microbial infections in the oral cavity.