Color stability and surface roughness of composite resins submitted to brushing with bleaching toothpastes: An in situ study

Objective To evaluate, in situ, the color stability (CS) and surface roughness (SR) of composite resins after toothbrushing with whitening toothpaste. Materials and Methods Specimens (6 x 2 mm/) of composite resin (Tetric N-Ceram, Z250 and Z350) were randomly fixed on thirty participants' upper molars (buccal surface). For an initial standardization (7 days), participants used a soft toothbrush and nonwhitening toothpaste (SDB - Sorrisos Dentes Brancos). Initial CS (Easyshade) and SR (Surfcorder RS) measurements were performed. For SR, impressions of specimens were taken (Express, 3 M ESPE) to produce replicas in polyurethane resin (Axon F16, Abcol). Participants were randomly separated into three groups (n = 10) regarding used toothpaste (SDB; Close up White Now - CWN; Colgate Luminous White - CLW). After 90 days, CS and SR measurements were obtained, and data were analyzed (2-way ANOVA, repeated measures, Bonferroni, P < .05). Results Z250 showed higher (P < .05) color change than Z350. Tetric N-Ceram presented an intermediary value for Delta E, however, it also demonstrated higher SR (P < .05) after brushing with CLW, compared with SDB and CWN. Conclusions The SR change of composite resin after toothbrushing with a whitening toothpaste is material dependent, but the toothpaste abrasiveness does not change the CS. Clinical significance Whitening toothpaste do not change the color stability of composites; however, it can alter the restorative composite surface roughness.