Effect of bleaching on the color match of single-shade resin composites.

Purpose: To evaluate the color match of single-shade resin composites before and after bleaching procedures, through instrumental and visual analyses.

Methods: Class V cavities were created on the buccal surfaces of 80 extracted human molars, restored with 4 single-shade composites (Omnichroma; Clearfil Majesty ES-2 Universal; Essentia Universal; Venus Diamond One). A spectrophotometer (VITA Easyshade V) was used to evaluate the tooth/resin color match before (T₀), and 24 h (T₁) and one week (T₂) after dental bleaching (Opalescence Boost PF 40%). Color variations (ΔE₀₀) were calculated and statistically analyzed (P < 0.05). Visual analysis was performed before and after tooth bleaching.

Results: Spectrophotometric evaluations revealed statistically significant differences between materials at T₀, T₁, and T₂ (P < 0.05). Visual analysis reported excellent and very good grades (0 and 1, respectively), irrespective of the materials and timepoints.

Conclusion: Data seem to indicate that single shade composites are able to shift their color when the surrounding tooth undergoes bleaching effects. Single-shade composites seem to achieve a good color match with the surrounding tooth structure, before and after professional bleaching.