Effect of Potassium Iodide, Bleaching, and Microabrasion on the Colour of Silver Diamine Fluoride Stained Remineralised Caries Lesions.

PURPOSE: This study aimed to investigate the effect of potassium iodide (KI), bleaching, and microabrasion on the colour of caries-like lesions treated with silver diamine fluoride (SDF). MATERIALS AND METHODS: Enamel specimens were demineralised and then randomised into six groups (n = 15): G1, demineralised; G2, remineralised with 38% SDF to create stained remineralised caries-like lesions (s-RCLs); G3, s-RCLs + KI; G4, s-RCLs + KI + at-home bleaching protocol (15% carbamide peroxide (CP), 4 h/dx7); G5, s-RCLs + KI + microabrasion (6.6% hydrochloric acid); G6, s-RCLs + KI + microabrasion and at-home bleaching protocol. Colour was measured spectrophotometrically at baseline, after demineralisation, and after the treatments. Outcomes were analysed using ANOVA followed by Tukey's test (alpha = 0.05). RESULTS: The increased colour change after demineralisation (DeltaE >/= 6.7) indicated the creation of white spot lesions. G2 (DeltaE = 12.3) and G3 (DeltaE = 11.1) were significantly discoloured (P </= 0.0039), with no significant difference between them, and significantly darker (P 0.0001) than G1 (DeltaE = 0.4) and G5 (DeltaE = 4.4). G2 was significantly (P </= 0.0325) darker than G1, G4, G5, and G6 (DeltaE = 0.4, 8.1, 4.4, 7.9), respectively. CONCLUSION: While KI did not reduce SDF staining, microabrasion offered limited aesthetic improvement. However, 15% CP demonstrated greater efficacy in partially improving the colour outcome of SDF-stained lesions.