VARIATION OF THE COLOR MATCH BETWEEN TOOTH AND RESTORATION AFTER DIFFERENT BLEACHING TREATMENTS

Aim: the aim of this in vitro study is to evaluate the effect of bleaching procedures on the color match between tooth and different composite restorations. Methods: the color of 60 extracted teeth was recorded using a spectrophotometer to include only teeth matching A2, A3, B3, C2-C4, D3, D4 VITA values. A standardized Class V cavi- ty (2 x 4 x 4 mm) was prepared on the buccal surface of each tooth, 1 mm above the CEJ. Teeth were randomized into 3 groups (n = 20) based on the composite used for the restora- tions: VB, VD and VP. Color differences (ΔE00) between tooth and restoration were calculated to exclude samples that did not meet the perceptibility criteria (ΔE00 ≤1.8) and to ensure a homogeneous initial sample. Half of the teeth (n = 10) were treated with a 25% H2O2 professional use gel, and the other half with a 6% H2O2 gel at-home use. CIELAB coordinates (L*, a*, b*), C* and h° were recorded using a spectrophotom- eter. The ΔE00 between tooth and restoration was calculated 24 h after restoration (T0) and 24 h after bleaching (T1). Results: instrumental analysis showed statistically signifi- cant differences in ΔE00 values between T0 and T1 within each group (0.00142≤ p ≤0.00834), while no significant differ- ences were observed between the different groups when compared at each time point. Conclusions: ΔE00 values increase after bleaching could indi- cate a worst color match between tooth and the 3 tested resins, that becomes perceptible after the treatment. However, it would be clinically more relevant to perform a visual analysis of the color match between tooth and restoration after bleaching.