Browsing by Author "Sorkhdini, Parand"
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Item 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 DentistryObjectives 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.Item 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 DentistryObjectives 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.Item In vitro Rehardening and Staining Effects of Silver Diamine Fluoride with and without Mucin on Early Enamel Caries Lesions(Mosher & Linder, 2021-08) Sorkhdini, Parand; Crystal, Yasmi O; Tang, Qing; Lippert, Frank; Cariology, Operative Dentistry and Dental Public Health, School of DentistryPURPOSE: Investigating the rehardening ability of SDF and its individual components, silver and fluoride ions, on early enamel caries lesions using artificial saliva with and without mucin. METHODS: Early caries lesions were created in human permanent enamel specimens. The specimens (n=36 per group) were then treated with a single application of: SDF (38%), SDF followed by application of potassium iodide (SDF+KI), potassium fluoride (KF; fluoride control, 44,800 ppm F), silver nitrate (AgNO3; silver control, 253,900 ppm Ag), or deionized water (DIW). Immediately, the specimens were subjected to four days of continuous remineralization with or without mucin (n=18 per subgroup). Changes in Vickers surface microhardness from lesion baseline (∆VHN) were calculated. Data were analyzed using two-way (intervention vs. rehardening models) ANOVA. RESULTS: In both rehardening models (with or without mucin), SDF (∆VHN data; mean ± standard deviation; with/without mucin: 26±19/3±11) was significantly less effective in rehardening promotion than SDF+KI (37±12/39±16) and KF (40±17/41±29; p≤0.0332). Compared to AgNO3 (9±9/18±15) and DIW (3±7/12±9), SDF was more effective in the presence of mucin (p≤0.001) but not in its absence (similar to DIW – p=0.11; less effective vs. AgNO3 – p=0.0061). The presence of mucin significantly increased the rehardening ability of SDF (p<0.0001). However, mucin did not affect the extent of rehardening in the other groups (p≥0.082). SDF+KI and KF were superior in their ability in rehardening promotion than AgNO3 and DIW in both rehardening models (p<0.0001). In both rehardening models, ΔL* values from baseline to post-rehardening show that applying KI after SDF significantly lessened the dark staining caused by SDF (p<0.0001). Under the present in vitro conditions, SDF does not appear to enhance surface rehardening of early enamel caries lesions. The co-presence of mucin during rehardening enhanced the efficacy of SDF which warrants further investigation. CLINICAL SIGNIFICANCE: SDF+KI may be a viable option in rehadening of early enamel caries lesions.Item Maxillary expansion in an animal model with light, continuous force(E.H Angle Education and Research Foundation, 2018) Utreja, Achint; Bain, Carol; Turek, Brett; Holland, Robert; AlRasheed, Rawan; Sorkhdini, Parand; Roberts, W. Eugene; Orthodontics and Oral Facial Genetics, School of DentistryObjectives: Maxillary constriction is routinely addressed with rapid maxillary expansion (RME). However, the heavy forces delivered by most RME appliances to expand the palate may lead to deleterious effects on the teeth and supporting tissues. The objective of this study was to explore a more physiologic maxillary expansion with light continuous force. Materials and Methods: Twenty 6-week-old Sprague-Dawley rats were equally divided into experimental (EXPT) and control (CTRL) groups. A custom-fabricated archwire expansion appliance made from 0.014-inch copper-nickel-titanium wire was activated 5 mm and bonded to the maxillary molar segments of animals in the EXPT group for 21 days. The force applied to each maxillary segment was 5 cN. Microfocus x-ray computed tomography and histological analyses were used to compare the tooth movement and bone morphology in the midpalatal suture and buccal aspect of the alveolar process between the EXPT and CTRL groups. Descriptive statistics (mean ± standard error of the mean) and nonparametric statistical tests were used to compare the outcomes across groups. Results: Compared to the CTRL group, there was a statistically significant increase in buccal tooth movement and expansion of the midpalatal suture in the EXPT group. There was no difference in the bone morphologic parameters between groups. The mineral apposition rate was increased on the buccal surface of the alveolar process in the EXPT group. Conclusions: Application of light, continuous force resulted in maxillary osseous expansion due to bilateral sutural apposition and buccal drift of the alveolar processes. This animal experiment provides a more physiologic basis for maxillary expansion.Item 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, SarahDental 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.Item 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 DentistryBackground 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.