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

Abstract

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 (triangle 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 triangle E values at each time point, except between the single and repeated KI groups on Day 1. The Group I exhibited the highest triangle E 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.