Effects of glutathione and potassium iodide on silver diamine fluoride application on remineralisation and colour change in dentine caries of primary teeth: an in vitro study.

purposeThe aim of this study is to compare the effect of GSH (reduced glutathione) and KI (potassium iodide) on SDF (silver diamine fluoride) discolouration and dentine remineralisation.

methodsSixteen primary molars were utilised, yielding 4 dentine 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 dentine specimen per tooth. Subsequently, all groups underwent exposure to a demineralisation solution. Colorimetry assessed specimen colour, and post-second microhardness measurements on demineralised 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 dentine specimens. Final microhardness measurements ensued, followed by statistical analysis. Normality was checked via Shapiro-Wilk, and 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, and Kruskal-Wallis for non-normally distributed ones. Repeated measures ANOVA compared dependent groups with normal distribution, and Friedman test for non-normal. Post hoc Bonferroni analyses identified significant differences. IBM SPSS 25 was used to conduct analyses.

resultsThe mean ΔE* values for SDF and SDF + GSH groups were significantly higher than those of the SDF + KI group (p < 0.05). Significant differences in L* values during final colour measurement were noted between the SDF + KI group and both SDF and SDF + GSH groups (p < 0.05). Although mean remineralisation microhardness measurements were higher than mean demineralisation microhardness measurements in all groups, statistical significance was observed only in the SDF and SDF + KI groups (p < 0.05).

conclusionThe study found that the addition of 5% GSH by weight to SDF does not significantly affect discolouration. Moreover, the addition of 5% GSH to the SDF solution may have a minor impact on the remineralisation potential of SDF. The application of KI after SDF reduces discolouration and does not affect the expected remineralisation process.