Effect of a clinically feasible repeated potassium iodide application protocol on silver diamine fluoride-induced discoloration.

Purpose: The aim is to evaluate and compare the effects of single versus repeated applications of potassium iodide (KI) on SDF-induced discoloration in primary canines. Materials and Methods: Thirty-six extracted human primary canines with dentinal caries were randomly allocated into three groups: Group I received 38% SDF alone; Group II received SDF followed by a single KI application; and Group III received SDF followed by immediately application after SDF and repeated on days 1, 3, and 5. Color change (∆E) was assessed on Days 1, 14, and 30 using a spectrophotometer based on the CIE Lab* system. Statistical analysis included One-Way ANOVA with Tukey post hoc tests for between-group comparisons, and Repeated Measures ANOVA with Bonferroni adjustment for within-group comparisons. Results: All groups showed significant differences in ΔE values at each time point, except between the single and repeated KI groups on Day 1. The Group I exhibited the highest ΔE values throughout the study, indicating the greatest discoloration, while Group III resulted in the lowest values. Over time, a progressive increase in discoloration was observed in Groups II, whereas partial color stability was maintained in Group III. Conclusion: Repeated application of KI after SDF treatment can result in a higher reduction in tooth discoloration compared to a single-application. This protocol may enhance the clinical acceptability of SDF, especially for visible anterior teeth in pediatric patients.