Gingival irritation in patients submitted to at-home bleaching with different cutouts of the bleaching tray: a randomized, single-blind clinical trial

Objectives This split-mouth randomized, single-blind clinical trial evaluated the gingival irritation (GI) of at-home bleaching with individual trays of different cutouts, as well as the tooth sensitivity (TS) and color change. Materials and methods One hundred and twenty patients were randomized as to which side would receive the type of bleaching tray cutout: scalloped (in the gingival margin) and nonscalloped (extended from the gingival margin). The at-home bleaching was performed for 30 min with 10% hydrogen peroxide (HP) for 2 weeks. The absolute risk and intensity of GI and TS were assessed with a visual analog scale. Color change was assessed using a digital spectrophotometer and a color guide ( α = 0.05). Results The proportion of patients who experienced GI was 57.5% (odds ratio 95% CI = 1.1 [0.7 to 1.8]), with no significant difference between groups ( p = 0.66). The proportion of patients who experienced TS was 64.1% (odds ratio 95% CI = 1.0 [0.6 to 1.6]), with no significant difference between groups ( p = 1.0). There is equivalence of scalloped and noscalloped groups for GI intensity ( p < 0.01). Significant whitening was detected for both groups. Although some differences were observed between groups (CIEL ab and CIEDE 00 ; p < 0.02), these were below of the considered clinically noticeable. Conclusions The different cutouts of trays proved to be equivalent when regarding gengival irritation and tooth sensitivity when 10% HP for at-home bleaching was used. Significant color change was observed in both groups. However, significant differences detected between groups are not considered clinically noticeable. Trial registration Brazilian Clinical Trials Registry (RBR-2s34685). Clinical relevance Scalloped or not, the individual trays for at-home bleaching could be considered a clinician’s decision.