Effect of silver diamine fluoride and potassium iodide pretreatment on microleakage, penetration depth, and color changes of fissure sealants: an in vitro study

This in vitro study aimed to evaluate and compare the effects of SDF- and SDF + KI-based pretreatment protocols, with or without NaOCl surface preparation, on microleakage, discoloration, and fissure sealant penetration depth in permanent teeth. Sixty extracted mandibular permanent molars with non-cavitated initial enamel lesions (ICDAS score 1) were randomly allocated into six groups (n = 10 per group). According to the experimental design, SDF, SDF + KI, NaOCl surface preparation, and orthophosphoric acid etching protocols were applied before fissure sealant placement. Color measurements were performed using a spectrophotometer according to the CIE Lab* system at baseline (T0) and after all procedures (T1). Microleakage and penetration depth were evaluated using confocal laser scanning microscopy (CLSM). Statistical analyses were performed using the Kruskal–Wallis test and Bonferroni-adjusted pairwise comparisons (α = 0.05). Significant differences were observed among the groups for color change (ΔE) and lightness change (ΔL) (p 0.05). SDF and SDF + KI pretreatments did not result in statistically significant differences in microleakage or penetration depth under the present experimental conditions, although SDF was associated with clinically relevant discoloration. KI showed only a limited effect in reducing this discoloration. NaOCl application was associated with less unfavorable lightness change in some comparisons; however, this finding should be interpreted cautiously.