The Effect of Glutathione Added Silver Diamine Fluoride on Remineralization and Color Change in Dentin Caries of Primary Teeth: an in Vitro Study

Objectives: The aim of this study is to compare the effect of GSH (reduced glutathione) and KI (potassium iodide) on SDF (silver diamin fluoride) discoloration and dentin remineralization. Materials: and methods: Sixteen primary molars were utilized, yielding four dentin specimens each. Three specimens per tooth were allocated: one as a control and the others to experimental groups. Initial microhardness measurements were taken from one remaining dentin specimen per tooth. Subsequently, all groups underwent exposure to a demineralization solution. Colorimetry assessed specimen color, and post-second microhardness measurements on demineralized specimens, treatments were administered as follows: group 1 (control, n=16): 38% SDF, group 2 (n=16): 38% SDF followed by KI, group 3 (n=16): 38% SDF with 5% GSH added by weight. Following pH cycling across all groups, colorimetry reassessed 48 dentin specimens. Final microhardness measurements ensued, followed by statistical analysis. Normality was checked via Shapiro-Wilk, homogeneity via Levene's test. Independent samples t-test compared normally distributed groups; Mann-Whitney U compared non-normally distributed groups. ANOVA compared means of normally distributed groups; Kruskal-Wallis for non-normally distributed ones. Repeated measures ANOVA compared dependent groups with normal distribution, Friedman test for non-normal. Post-hoc Bonferroni analyses identified significant differences. IBM SPSS 25 conducted analyses. Results: : The mean ΔE* values for SDF and SDF+GSH groups were significantly higher than SDF+KI group (p<0.05). Significant differences in L* values during final color measurement were noted between SDF+KI group and both SDF and SDF+GSH groups (p<0.05). Although mean remineralization microhardness measurements were higher than mean demineralization microhardness measurements in all groups, statistical significance was observed only in SDF and SDF+KI groups (p<0.05). Conclusion: The study found that adding 5% GSH by weight to SDF does not significantly affect discoloration. Additionally, the addition of 5% GSH to SDF may impact its remineralization potential. The application of KI after SDF reduces discoloration and does not affect the expected remineralization process. Clinical relevance: In reducing discoloration, KI can be used following SDF applications. Repeated SDF applications may accelerate the expected remineralization process.