Browsing by Subject "Dental enamel"

Now showing 1 - 6 of 6
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    Effect of phenylmethylsulfonyl fluoride, a protease inhibitor, on enamel surface remineralization
    (SciELO, 2023) Peres, Paulo Edelvar Corrêa; Fu, Jean; Zero, Domenick T.; Cury, Jaime Aparecido; Biomedical and Applied Sciences, School of Dentistry
    Phenylmethylsulfonyl fluoride (PMSF) is a protease inhibitor widely used in research, but fluoride is released during its action and this knowledge has been neglected in dental research. Aim to evaluate if fluoride released by salivary protease action on PMSF affects enamel remineralization and fluoride uptake. Methods Groups of 10 enamel slabs, with caries-like lesions and known surface hardness (SH), were subjected to one of the following treatment groups: Stimulated human saliva (SHS), negative control; SHS containing 1.0 μg F/mL (NaF), positive control; and SHS containing 10, 50 or 100 µM PMSF. The slabs were subjected to a pH-cycling regimen consisting of 22 h/day in each treatment solution and 2 h/day in a demineralizing solution. After 12 days, SH was again measured to calculate the percentage of surface hardness recovery (%SHR), followed by enamel fluoride uptake determination. The time-related fluoride release from 100.0 µM PMSF by SHS action was also determined. Data were analyzed by ANOVA followed by Newman-Keuls test. Results The release of fluoride from PMSF by SHS was rapid, reaching a maximum value after 10 min. Fluoride released from PMSF was more effective in enhancing %SHR and increasing fluoride uptake in enamel compared with SHS alone (p < 0.05); furthermore, it was equivalent to the positive control (p > 0.05). Conclusion In conclusion, fluoride released by saliva from PMSF is available to react with enamel and needs to be taken into account in research using this protease inhibitor.
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    Exploratory Analysis of Objective Outcome Measures for the Clinical Assessment of Erosive Tooth Wear
    (MDPI, 2023-08-02) Romero, Maria Jacinta Rosario H.; Ungar, Peter S.; Fried, Daniel; Lippert, Frank; Zero, Domenick T.; Zunt, Susan; Eckert, George J.; Gutierrez Gossweiler, Ana; Elkington-Stauss, Dylan Jacob; Tamayo-Cabeza, Guillermo; Kelly, Adam B.; Bartels, Troy; Kita, Camille; Wewers, Elizabeth; Hara, Anderson T.; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    This study proposed using enamel surface texture and thickness for the objective detection and monitoring of erosive tooth wear (ETW), comparing them to the standard subjective Basic Erosive Wear Evaluation (BEWE). Thirty-two subjects (n = 597 teeth) were enrolled in this longitudinal observational clinical study. Enamel thickness (by cross-polarization optical coherence tomography, CP-OCT) and 3D dental microwear parameters, i.e., area-scale fractal complexity (Asfc), anisotropy (Str), and roughness (Sa) (by white-light scanning confocal profilometry), were obtained from buccal surfaces. Buccal, occlusal, and lingual surfaces were scored for BEWE and the maximum score per tooth (BEWEMax) was determined at baseline and 12 months (M12). Data outcome relationships were evaluated (alpha = 0.05). Enamel thickness decreased (p < 0.001), BEWE scores, Sa, and Str increased (p < 0.001), while Asfc did not change at M12. Baseline BEWEBuccal correlated strongly with BEWEMax (r = 0.86, p < 0.001) and moderately with BEWELingual (r = 0.42, p < 0.001), but not with enamel thickness (r = 0.03, p = 0.43). Change (Δ) in surface texture outcomes correlated poorly but significantly with ΔBEWEBuccal (r = −0.15–0.16, p < 0.001) and did not correlate with Δenamel thickness (r = 0.02–0.09, p > 0.06). Teeth with BEWE progression revealed a greater increase in ΔSa and ΔStr. These findings suggest that enamel surface roughness can potentially determine ETW severity, and CP-OCT may be relevant for clinically monitoring enamel thickness.
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    Fluorotic Enamel Susceptibility to Dental Erosion and Fluoride Treatment
    (Ribeirão Preto Dental Foundation, 2023) Silva, Cristiane Araújo Maia; de Sousa, Frederico Barbosa; Martinez-Mier, Esperanza Angele; Vieira, Basílio Rodrigues; do Nascimento, Johnatan Meireles; Hara, Anderson Takeo; Dental Public Health and Dental Informatics, School of Dentistry
    The purpose of this in vitro study was to test the hypothesis that fluoride treatment can prevent dental erosion on fluorotic enamel of different severities. It followed a 3×2 factorial design, considering a) fluorosis severity: sound (TF0, Thylstrup-Fejerskov Index), mild (TF1-2), moderate (TF3-4); and b) fluoride treatment: 0 (negative control) and 1150ppmF. Human molars with the three fluorosis severities (n=16, each) were selected and randomly assigned to the two fluoride treatments (n=8). Enamel blocks (4×4mm) were prepared from each tooth and subjected to a dental erosion cycling model, for 10 days. The daily cycling protocol consisted of erosive challenges (1% citric acid, pH 2.4), interspersed by periods of immersion in artificial saliva, and three 2-minute treatments with either 0 or 1150ppm F. The enamel volume loss (mm3) was calculated by subtracting values obtained by microtomography before and after cycling. Two-Way ANOVA showed no significant interaction between fluorosis severity and fluoride treatment (p=0.691), and no significant effect for either fluorosis severity (TF0 mean±standard-deviation: 13.5(10-2±0.42(10-2, TF1-2: 1.50(10-2±0.52(10-2, TF3-4: 1.24(10-2±0.52(10-2, p=0.416) or treatment (0ppmF: 1.49(10-2±0.53(10-2; 1150ppmF: 1.21(10-2±0.42(10-2; p=0.093), when evaluated independently. Considering the limitations of this in vitro study, the presence and severity of fluorosis in enamel do not appear to affect its susceptibility to dental erosion. Fluoride treatment was not effective in preventing the development of dental erosion in both sound and fluorotic enamel substrates under our experimental conditions.
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    Investigations of the anti-caries potential of fluoride varnishes
    (2015-11-12) Al Dehailan, Laila Adel; Martinez-Mier, Esperanza Angeles; Lippert, Frank; Soto-Rojas, Armando E.; González-Cabezas, Carlos; Stelzner, Sarah
    The majority of currently marketed fluoride varnishes (FV) have not been evaluated for their effectiveness in preventing dental caries. Fundamental research on FVs and how different formulations affect adherence to teeth, fluoride release into saliva and uptake by teeth is virtually non-existent. The objective of this work was to investigate the anti-caries potential, measured as fluoride release into saliva, change in surface microhardness of early enamel caries lesions, and enamel fluoride uptake, of multiple commercially available FVs. We have found that FVs differed in their release characteristics, rehardening capability, and ability to deliver fluoride to demineralized lesions. In addition to our in vitro work, we have conducted a clinical study that aimed to compare saliva and plaque fluid fluoride concentrations following the application of three commercially available FV treatments at predetermined post application time points. We also investigated the change in fluoride concentration in saliva and plaque fluid fluoride from baseline to each post application predetermined time point. We found that FVs varied in their release of fluoride into saliva and plaque fluid but shared common trends in release characteristics. The outcomes of our in vitro and in vivo investigations demonstrate a great variation in anti-caries potential of FVs. This may be attributed to different compositions and physical properties of the tested FVs.
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    Relationship between enamel fluorosis severity and fluoride content
    (Elsevier, 2016-03) Martinez-Mier, Esperanza A.; Shone, Devin B.; Ando, Masatoshi; Lippert, Frank; Soto-Rojas, Armando E.; Department of Pediatric Dentistry, IU School of Dentistry
    OBJECTIVES: Enamel fluorosis is a hypomineralization caused by chronic exposure to high levels of fluoride during tooth development. Previous research on the relationship between enamel fluoride content and fluorosis severity has been equivocal. The current study aimed at comparing visually and histologically assessed fluorosis severity with enamel fluoride content. METHODS: Extracted teeth (n=112) were visually examined using the Thylstrup and Fejerskov Index for fluorosis. Eruption status of each tooth was noted. Teeth were cut into 100 μm slices to assess histological changes with polarized light microscopy. Teeth were categorized as sound, mild, moderate, or severe fluorosis, visually and histologically. They were cut into squares (2 × 2 mm) for the determination of fluoride content (microbiopsy) at depths of 30, 60 and 90 μm from the external surface. RESULTS: Erupted teeth with severe fluorosis had significantly greater mean fluoride content at 30, 60 and 90 μm than sound teeth. Unerupted teeth with mild, moderate and severe fluorosis had significantly greater mean fluoride content than sound teeth at 30 μm; unerupted teeth with mild and severe fluorosis had significantly greater mean fluoride content than sound teeth at 60 μm, while only unerupted teeth severe fluorosis had significantly greater mean fluoride content than sound teeth at 90 μm. CONCLUSIONS: Both erupted and unerupted severely fluorosed teeth presented higher mean enamel fluoride content than sound teeth. CLINICAL SIGNIFICANCE: Data on fluoride content in enamel will further our understanding of its biological characteristics which play a role in the management of hard tissue diseases and conditions.
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    Tactile perception of roughness to assess activity in artificial initial caries lesions with a novel force-controlled probe
    (SciELO Brazil, 2022) Martignon, Stefania; Castiblanco-Rubio, Gina Alejandra; Braga, Mariana Minabel; Cortes, Andrea; Usuga-Vacca, Margarita; Lara, Juan Sebastian; Mendes, Fausto Medeiros; Avila, Viviana; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Roughness-tactile perception is part of activity assessment in initial-caries-lesions. Hypothesizing that a probe’s design influences this examiner’s assessment, four probes were designed. The aims of this study were to select the probe with highest inter-/intra-examiners’ roughness-assessment agreement and to determine its diagnostic accuracy on artificial initial-caries lesions. A pilot study was conducted with trained dentists to select one controlled-pressure probe design (n = 4) by assessing roughness on known-roughness metal plaques with 5-point Likert scale. Diagnostic accuracy of roughness assessment was conducted with the selected controlled-pressure probe and the WHO-probe on sound and artificial initial-caries-lesion (n = 20) human enamel blocks. Intra-class correlation coefficients (ICCs) and quadratic weighted-Kappa scores were used to assess examiners’ reproducibility and Multilevel Poisson models to determine diagnostic accuracy between both probes controlling for confounding variables. The probe design with the highest inter/intra-examiner’s agreement (ICC = 0.96) was selected for subsequent analyses. Unadjusted sensitivity, specificity and accuracy values were for the controlled-pressure and the WHO probes: 71.1%,90.6%,81.2%, and 67.4%,84.6%,75.8%, respectively (p > 0.05). Examiner remained the most important factor influencing diagnostic accuracy. While this study did not show significantly higher diagnostic accuracy of the designed controlled-pressure vs. the WHO-probe when used by trained dentists, all over roughness-assessment accuracy and reproducibility were high.