Browsing by Subject "enamel fluorosis"

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    In vitro Validation of Quantitative Light-Induced Fluorescence for the Diagnosis of Enamel Fluorosis in Permanent Teeth
    (Karger, 2017-11) Cuevas-Espinosa, D. M.; Martinez-Mier, E. Angeles; Ando, Masatoshi; Castiblanco, G. A.; Cortes, F.; Rincon-Bermudez, C. M.; Martignon, Stefania; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    This study aimed to validate quantitative light-induced fluorescence (QLF) as a diagnostic tool for mild and moderate enamel fluorosis in permanent teeth, comparing it to visual diagnosis and histological assessment completed using polarized light microscopy (PLM). The buccal surfaces of 139 teeth were visually classified using the Thylstrup and Fejerskov Index (TFI) into sound (TFI 0; n = 17), mild (TFI 1-2; n = 69), and moderate (TFI 3-4; n = 43) fluorosis. Fluorosis was then assessed with QLF (variables ΔF, A, and ΔQ at 5-, 15-, and 30-radiance thresholds) using as reference areas the entire surface and a region of interest (ROI), identified as the most representative region of a fluorosis lesion. PLM images of longitudinal thin sections including the ROI were assessed for histological changes. Correlations among TFI, PLM, and QLF were determined. A receiver-operating characteristic curve was conducted to determine QLF's diagnostic accuracy when compared to the TFI and PLM assessments. This was used to assess the probability that the images were correctly ranked according to severity as determined by PLM and TFI. A positive correlation was found between QLF and PLM, and between QLF and TFI. QLF showed the highest sensitivity and specificity for the diagnosis of mild fluorosis. There was also a strong agreement between TFI and PLM. The selection of a ROI resulted in a stronger correlation with TFI and PLM than when the entire surface was used. The study results indicate that defining an ROI for QLF assessments is a valid method for the diagnosis of mild and moderate enamel fluorosis.
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    Relative fluoride response of caries lesions created in fluorotic and sound teeth studied under remineralizing conditions
    (Elsevier, 2015-01) Alhawij, Hala; Lippert, Frank; Martinez-Mier, Esperanza Angeles; Department of Cariology, Operative Dentistry and Dental Public Health, IU School of Dentistry
    Objectives The present in vitro pH cycling study investigated potential differences between caries lesions created in fluorosed and sound enamel with regards to their responsiveness to fluoride under remineralizing conditions. Methods 360 human first molars (sound and fluorosed) were divided into four groups based on their Thylstrup–Fejerskov score (TF0-3). Each group was further divided into two treatment groups (n = 45): deionized water or 383 ppm fluoride. Artificial enamel caries lesions were created and pH cycled for 20 d using an established net remineralization model. Quantitative light-induced fluorescence was used throughout the study to investigate lesion severity and changes thereof. Data were analyzed using two-way ANOVA. Results There were no differences in lesion severity between all groups after lesion creation (plesion = 0.1934). The TF score vs. treatment interaction was significant at all other time points (p10 d = 0.0280; p20 d ≤ 0.0001; psecdemin = 0.0411). Relative differences in responsiveness to fluoride vs. deionized water increased with increasing TF scores. In comparison to lesions created in sound enamel, lesions created in enamel with moderate fluorosis (TF 2/3) were more prone to remineralization in the presence than in the absence of fluoride. Furthermore, lesions created in enamel with moderate fluorosis exhibited more remineralization in the presence of fluoride than lesions created in sound teeth, whereas the opposite was true for deionized water. Conclusion Bearing in mind the limitations of laboratory research, the extent of enamel fluorosis severity may directly impact subsequent lesion re- and progression as well as the lesion's responsiveness to fluoride. Clinical relevance Caries lesions in fluorotic teeth are more vulnerable to progression but respond more strongly to fluoride than those in non-impacted teeth.
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    Teeth With Mild and Moderate Enamel Fluorosis Demonstrate Increased Caries Susceptibility In Vitro
    (Elsevier, 2017) Martinez-Mier, E. Angeles; Lippert, Frank; Department of Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Subjects In this laboratory study, 49 human unerupted third molars extracted for clinical reasons and classified as scores 0-4 using the Thylstrup and Fejerskov (TF) index (n = 9 for TF0, n = 10 for TF1, n = 10 for TF2, n = 10 for TF3, and n = 10 for TF4) were included. TF1-TF4 teeth were collected in Colombia, and TF0 teeth were obtained from the University of Copenhagen. Ethical approval was obtained. Key Risk/Study Factor Teeth in the study were subjected to pH cycling to induce caries lesions. Main Outcome Measure The primary outcome measure was resistance to a cariogenic challenge determined using cross-sectional microhardness. A series of indentations, starting at 10 μm below the anatomic surface down to 200 μm, were placed in the teeth using a Knoop indenter. These measurements were performed before and after pH cycling, yielding baseline and demineralization areas, both calculated “by numerical integration of the hardness vs depth values using the trapezoidal rule.” The demineralization data were then normalized for differences at baseline and a “percentage reduction” was calculated, with higher numbers being indicative of greater susceptibility to caries lesion formation. Main Results Teeth with scores of TF3 and TF4 exhibited greater susceptibility to caries lesion formation than all other teeth, with no differences being observed between unaffected teeth (TF0) and teeth with scores of TF1 and TF2. Teeth with scores of TF3 and TF4 also displayed a lower mean baseline area than those with TF1 and TF2, although not compared to TF0 teeth, indicative of greater hypomineralization. Conclusions The authors concluded that the results of their study suggest that teeth with moderate fluorosis had an increased caries susceptibility when compared to teeth with very mild or no fluorosis. They hypothesized that these differences in caries susceptibility are mainly due to dissimilarities in porosity of the enamel—in fluorotic teeth, a greater subsurface mineral area is exposed to demineralization, and deeper acid diffusion through enamel is facilitated.