Managing Post-Treatment Discoloration in Resin-Infiltrated Teeth: Comparative Effects of Polishing and Bleaching

Resin infiltration is an effective minimally invasive treatment for white spot lesions, but post-treatment discoloration remains a significant clinical challenge with limited evidence-based management protocols.

This study evaluated the effectiveness of polishing and bleaching techniques in enhancing the color of resin-infiltrated teeth.

Fifty caries-free, extracted permanent human teeth were randomly allocated to control and study groups (n = 25). All specimens were cleaned, sectioned mesiodistally, mounted in acrylic resin, and examined for surface imperfections. The study group underwent standardized artificial demineralization to create 50-µm white spot lesions, followed by ICON resin infiltration. Both groups completed a 30-day staining protocol with twice-daily 15-minute immersions in standardized coffee solution and brushing. Interventions included (1) mechanical polishing and (2) 14-day bleaching (9.5% H2O2 gel, 30-minute daily applications). Color changes were quantitatively assessed at baseline, post-polishing, and post-bleaching using spectrophotometry (Vita Easyshade) with CIELAB/CIEDE2000 systems and Vitapan Classical shade scores. Statistical analysis employed paired t-tests, ANOVA, and mixed ANOVA (α = 0.05).

At baseline, resin-infiltrated teeth were significantly darker (lower L*) and redder (higher a*) compared to untreated controls (p < 0.005). Mechanical polishing improved color parameters in both groups and effectively minimized intergroup differences (ΔE00: 6.90 vs 6.84; p = 0.49). Bleaching produced significantly greater color change in resin-infiltrated teeth compared to controls (ΔE00 from baseline: 17.6 vs 11.4, p < 0.001). Vitapan shade scores improved significantly across sequential treatment stages (baseline, post-polishing, post-bleaching; p < 0.001), with no significant intergroup differences in final scores (p = 0.49).

Polishing reduced surface stains and color differences, but bleaching achieved greater whitening, especially in resin-infiltrated teeth. Together, they offer an effective approach for managing post-infiltration discoloration.