Bleaching efficacy and quality of life of different bleaching techniques — randomized controlled trial

Objectives To evaluate bleaching efficacy and oral health-related quality of life (ORHQoL) of three bleaching systems with similar hydrogen peroxide (HP) concentration for up to 6 months post-treatment. Materials and methods A randomized controlled trial was designed with three parallel groups: group A — in-office 6% HP paint-on varnish; group B — at-home 6% HP with adaptable tray; group C — at-home 16% carbamide peroxide with custom tray. At three different stages (baseline, after bleaching, and 6-month follow-up), ORHQoL was evaluated by the OHIP-14 questionnaire and tooth color of the upper canines and central incisors were measured by two shade guides and a spectrophotometer (measuring CIE L*a*b* with respective color/whiteness differences − Δ E 00 /ΔWI D ). Results were presented as mean and 95% confidence intervals and statistical tests were performed appropriately, considering a significance level of α = 0.05. Results All groups presented significant color differences ( P