Browsing by Author "Crystal, Yasmi O."

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    The effect of silver diamine fluoride in preventing in vitro primary coronal caries under pH-cycling conditions
    (Elsevier, 2021-01) Sorkhdini, Parand; Crystal, Yasmi O.; Tang, Qing; Lippert, Frank; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Objectives This study investigated the ability of SDF, and its individual components, silver (Ag+) and fluoride (F−) ions, in preventing enamel demineralization under pH-cycling conditions in the presence or absence of twice-daily fluoride application. Design Polished human enamel specimens were assigned to five treatment groups (n = 36 per group): SDF (38 %); SDF followed by application of a saturated solution of potassium iodide (SDF + KI); silver nitrate (AgNO3; silver control, 253,900 ppm Ag); potassium fluoride (KF; fluoride control, 44,800 ppm F); deionized water. Treatments were applied once. Specimens in each treatment group were divided into two subgroups (n = 18). During the subsequent 7-day pH-cycling phase, specimens were treated twice daily with either 275 ppm fluoride as sodium fluoride or deionized water, immediately before and after a 3-h cariogenic challenge with exposure to artificial saliva at all other times. Changes in color, Vickers surface microhardness (SMH), transverse microradiography (TMR) was calculated. Data were analyzed using two-way ANOVA. Results In both models, SDF, SDF + KI and KF were superior in inhibiting demineralization compared to AgNO3 and deionized water (p < 0.0001). There was no statistically significant difference between SDF, SDF + KI and KF with twice daily fluoride treatments (p > 0.8). However, KF was more effective in preventing demineralization than SDF and SDF + KI in the absence of fluoride treatments (p = 0.0002). KI did not affect the ability of SDF to prevent demineralization (p > 0.4). Conclusion SDF and SDF + KI appears to be an effective option in preventing primary coronal caries.
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    Effectiveness of in vitro primary coronal caries prevention with silver diamine fluoride - Chemical vs biofilm models
    (Elsevier, 2020-08) Sorkhdini, Parand; Gregory, Richard L.; Crystal, Yasmi O.; Tang, Qing; Lippert, Frank; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Objectives The main goal of this study was to investigate the effectiveness of SDF and its individual components, silver (Ag+) and fluoride (F−) ions, in preventing enamel demineralization using biofilm and chemical models. Methodes Polished human enamel specimens were assigned to five treatment groups (n = 18 per group): SDF (38 %); SDF followed by application of a saturated solution of potassium iodide (SDF + KI); silver nitrate (AgNO3; silver control, 253,900 ppm Ag+); potassium fluoride (KF; fluoride control, 44,800 ppm F); deionized water (DIW). Treatments were applied once to sound enamel. In the biofilm model, specimens were demineralized by aerobic overnight incubation using cariogenic bacteria isolated from human saliva in brain heart infusion supplemented with 0.2 % sucrose for three days. In the chemical model, enamel specimens were immersed in a demineralizing solution containing 0.1 M lactic acid, 4.1 mM CaCl2, 8.0 mM KH2PO4, 0.2 % Carbopol 907, pH adjusted to 5.0 for five days. Vickers surface microhardness was used to determine the extent of enamel demineralization. Data were analyzed using one-way ANOVA. Results In the chemical model, there was no statistically significant difference between SDF and SDF + KI in preventing coronal caries (p < 0.0001). In the biofilm model, SDF + KI was significantly less effective in preventing demineralization than SDF (p < 0.0001). In both models, SDF and SDF + KI were superior in their ability to prevent caries lesion formation than AgNO3 and DIW. Conclusion KI application after SDF treatment appears to impair SDF’s ability to prevent biofilm-mediated but not chemically induced demineralization.
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    Primary Coronal Caries Prevention with Silver Diamine Fluoride – Investigations into Efficacy and Mode of Action
    (2021-01) Sorkhdini, Parand; Lippert, Frank; Gregory, Richard; Martinez Mier, E. Angeles; Crystal, Yasmi O.; Stelzner, Sarah
    Dental caries continues to be one of the most prevalent preventable diseases worldwide. Silver diamine fluoride (SDF) is a topical solution comprised of silver, ammonia and fluoride. It is a safe, effective, efficient, noninvasive and cost-effective method in caries management. However, there is little clinical evidence supporting the use of SDF (or SDF followed by application of potassium iodide[KI] to mitigate staining) as anti-caries agents on sound enamel and early enamel carious lesions. In this dissertation, I studied the mechanism behind SDF’s ability to prevent coronal caries which has not been studied yet. In the first and second aims, I investigated the effectiveness of SDF, SDF+KI, fluoride (potassium fluoride [KF]) and silver (silver nitrate [AgNO3]) controls to SDF and deionized water (DIW) in preventing enamel demineralization and enhancing remineralization using chemical, biofilm and pH-cycling models. In both chemical demineralization and pH-cycling models there were no statistically significant differences between SDF and SDF+KI in preventing coronal caries. In the biofilm model, however, SDF+KI was significantly less effective in preventing demineralization than SDF. In the third aim, I investigated the efficacy of SDF, SDF+KI, KF, AgNO3, and DIW on the remineralization of active subclinical enamel carious lesions. Here, SDF+KI was significantly more effective in promoting remineralization than SDF. I calculated changes in color, and the results show applying KI after SDF significantly reduced the dark staining caused by SDF. In conclusion: SDF and SDF+KI appear to be effective options in preventing and in the treatment of primary coronal caries. Further clinical research is required to confirm the present findings.
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    The effect of silver diamine fluoride on the remineralization of early enamel carious lesions under pH-cycling conditions
    (Elsevier, 2022) Sorkhdini, Parand; Crystal, Yasmi O.; Tang, Qing; Lippert, Frank; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Background This study explored the in vitro anticaries efficacy of silver diamine fluoride (SDF) in remineralizing early enamel carious lesions. Methods Lesions were created in human enamel specimens, which were divided into 5 groups (n = 36): SDF (38%), SDF and potassium iodide (SDF and KI), potassium fluoride (KF), silver nitrate (AgNO3), and deionized water (DIW). Treatments were applied once. Groups were divided into 2 subgroups (n = 18), pH cycled for 5 days with twice-daily treatments with either fluoride or DIW. Vickers hardness number measurements were conducted at each stage. Data were analyzed using a 2-way analysis of variance. Results The 2-way analysis of variance for ΔVickers hardness number was significant (P < .0001). In both pH-cycling models (with or without fluoride), SDF, SDF and KI, and KF promoted more remineralization than AgNO3 and DIW (P < .0001). In the presence of twice-daily fluoride treatments, there was no difference between SDF, SDF and KI, and KF (P = .4577). However, in the absence of fluoride treatments, SDF promoted more remineralization than SDF and KI and KF (P < .0001). There were no differences between SDF and KI and KF (P = .4577 and P = .2156; pH-cycling models with and without fluoride, respectively) and AgNO3 vs DIW (P = .6553 and P = .1194). Conclusion With the copresence of fluoride, SDF and SDF and KI equally promote remineralization of enamel lesions. KI impairs SDF-related remineralization in the absence of fluoride treatments.