Evaluating the Effect of Silver Diamine Fluoride, with or without Glutathione and Potassium Iodide, on Fluoride Release, Dentin Microhardness and Surface Properties of Dentin.

This study aimed to evaluate the effect of silver diamine fluoride (SDF) in combination with or without glutathione (Glu) and potassium iodide (KI) on the fluoride release and the enhancement of dentin microhardness. In this et al study, 90 intact premolar teeth from human subjects were allocated into nine groups, each consisting of ten samples: A) control; B) SDF; C) SDF combined with 5% Glu; D) SDF combined with 10% Glu; E) SDF combined with 20% Glu; F) KI after SDF; G) 5% Glu after SDF; H) 10% Glu after SDF; and I) 20% Glu after SDF. Data were analyzed using SPSS version 22 software and ANOVA and post-hoc and repeated measure test (P value <0.05). Dentin microhardness exhibited variations across different treatments, with the highest value being observed in the SDF-5% Glu group and the lowest in the control group. However, there was a significant difference between the mean values of SDF-5% Glu group and the SDF group. Significant increases in microhardness were observed when comparing SDF-5% Glu to SDF+5% Glu and SDF-10% Glu to SDF+10% Glu in peer groups (P value <0.05). Over time, there was a significant increase in the amount of fluoride released as compared to the initial day. The utilization of SDF-5% Glu group exhibited the most favorable effect on improving dentin hardness. Additionally, utilizing Glu in concentrations of 5% and 10% after SDF application proved more effective in increasing dentin microhardness than combining it with SDF. Moreover, in all three fluoride measurement periods, adding 5% Glu to SDF and using 20% Glu following SDF administration led to a significant increase in fluoride release compared to the application of SDF alone.

Effect of Nd:YAG and Er:YAG laser tooth conditioning on the microleakage of self-adhesive resin cement.

STATEMENT OF PROBLEM: Recently, the application of lasers in restorative dentistry has been considered for cavity preparation and surface conditioning of enamel and dentin. However, the beneficial effects of cavity surface conditioning by laser irradiation on microleakage are still controversial. PURPOSE: This study aimed to compare the microleakage of self-etch adhesive resin cement with Nd:YAG and Er:YAG laser tooth surface conditioning to evaluate the capabilities of these lasers as a reliable replacement for etching cavities. MATERIALS AND METHODS: Fifty-four class V cavities were prepared on the buccal and lingual surfaces of 27 sound human premolar teeth. The samples were randomly divided into three groups (n = 18): group 1: no conditioning; group 2: conditioned with Er:YAG laser (2940 nm, 10 Hz, 1.2 W); group 3: conditioned with Nd:YAG laser (1064 nm, 1.5 W, 10 Hz). All the cavities were filled with self-adhesive resin cement. After curing and polishing, the samples were immersed in 2% methylene blue solution for 24 h, and after being embedded in acrylic resin, they were sectioned longitudinally and examined under a stereomicroscope. The data were submitted to Kruskal-Wallis and Dunn tests (α = 0.05). RESULTS: The lowest microleakage mean rank was observed in the Er:YAG group (19.19), and the highest mean rank was noted in the Nd:YAG group (33.08), with significant differences between the three groups (P-value = .01). Pairwise comparisons demonstrated significant differences between the Er:YAG and Nd:YAG groups (P-value = .004) as well as Er:YAG and no conditioned groups (P-value =.022). CONCLUSION: The irradiation of the Er:YAG laser (2940 nm, 10 Hz, 1.2 W) on cavity surface resulted in less marginal microleakage of self-etch adhesive resin cement restorations compared to Nd:YAG (1064 nm, 1.5 W, 10 Hz) and no conditioning groups.

Inflammatory response of canine gingiva to a chemical retraction agent placed at different time intervals.

BACKGROUND: Exposure of the gingival sulcus while controlling hemorrhage is prerequisites for maximizing treatment outcomes of cervical carious lesions and for obtaining quality impressions for the fabrication of indirect restorations with cervical finish lines. Gingival retraction cords saturated with different chemical agents are widely used for this purpose. The aim of this study was to investigate and compare the inflammatory potential of 15.5%ferric sulfate on connective tissue when placed at different times. MATERIALS AND METHODS: All procedures were performed on three dogs under general anesthesia. Retraction cords saturated with a 15.5% ferric sulfate solution were placed into the gingival sulcus and evaluated after 3 min and 10 min of exposure to the chemical agent. Excisional biopsies of the exposed gingival tissue were then obtained at intervals of 1 h, 24 h, and 7 days. For all specimens, histology evaluation was performed using light microscopy. Data collected from the microscopic images of all tissue specimens were analyzed by using the Wilcoxon Signed Rank and Kruskal-Wallis Tests. P value less than 0.05 was considered as significant. RESULTS: Histopathologic examination of the biopsied gingival tissue revealed that the ferric sulfate solution caused significant tissue changes at the beginning of both the 3-min and 10-min gingival exposure time (P > 0.05). However, the tissue returned to a normal histological appearance by the end of day 7 in all cases (P > 0.05). CONCLUSION: The results of this study revealed that the biologic effects of 15.5% ferric sulfate solution are clinically acceptable and reliable when gingival exposure times of 3 min and 10 min are used for gingival retraction.

An in vitro comparison of microleakage of two self-etched adhesive and the one-bottle adhesive used in pit and fissure sealant with or without saliva contamination.

AIMS AND OBJECTIVES: To minimize the deleterious effects of contaminated enamel on bonding, some authors have advocated the use of adhesive systems under the sealant. The aim of this study was to compare the microleakage of two self-etch and the one-bottle adhesive used in pit and fissure sealant with or without saliva contamination. MATERIALS AND METHODS: Sixty extracted premolar teeth were assigned to the six groups. Group 1: Acid +saliva +single bond +sealant, Group 2: Acid +single bond +sealant, Group 3: Saliva +S (3) bond +sealant, Group 4: S (3) bond +sealant, Group 5: Saliva +protect bond +sealant, Group 6: Protect bond +sealant. The teeth were thermocycled and immersed in 2% basic fuchsine dye for 24 h, then sectioned and examined with a stereomicroscope under ×40 magnification. The results were evaluated with Kruskal-Wallis and Dunn tests. RESULTS: Group 2 has the lower microleakage scores than Groups 4 and 6. Also, Group 6 has the lower microleakage scores than Group 4, and generally an increase in microleakage was observed in each group related to contamination. CONCLUSION: The best technique of sealant therapy in saliva contaminated and non- contaminated condition is the use of acid-etching and bonding agent.

Effect of Using Electric Current during Dentin Bonding Agent Application on Microleakage under Simulated Pulpal Pressure Condition.

BACKGROUND: The use of electric current during application of etch-and-rinse adhesive systems has been recently introduced to decrease microleakage. This study investigated the effects of an electric field produced by an experimental device for the application of a two-step etch-and-rinse adhesive on moist dentin surface. METHODS: Sixty freshly extracted human premolars were used for this study. In order to simulate real conditions, the pulpal pressure was set to 35 cm H(2)O for all the specimens. The teeth were divided into two groups: in group I, etch-and-rinse system (Single Bond) was applied with electric current while group II, etch-and-rinse system (Single Bond) was applied without electric current. Specimens were prepared for dye penetration test. The data were analyzed using Mann-Whitney U test. RESULTS: The results showed that group I had less microleakage scores compared to group II (P = 0.047). CONCLUSION: Based on the result of this study, it could be concluded that using electric current for applying adhesive systems had a significant effect on reducing microleakage.