A randomized clinical trial investigating three vital tooth bleaching protocols and associated efficacy, effectiveness and participants' satisfaction.

Objectives: To compare tooth colour change and participant's satisfaction following: home (HB), in-office (IOB) and combined (CB) bleaching treatments.

Methods: A group of 105 participants received HB, IOB and CB treatments. HB was performed using custom-made trays and 10 % carbamide peroxide for 14 days. IOB was performed using 37.5 % hydrogen peroxide applied in 3 cycles. CB bleaching treatment involved IOB followed by HB. Tooth colour change was assessed visually (VC-ΔVC) and using a digital spectrophotometry device (ES-ΔeVS). Participant's perception of oral health, smile and straightness and whiteness of teeth were evaluated using self-reported questionnaire. Parameters/responses were evaluated/collected prior bleaching and at recalls. Linear mixed models were used to estimate between- and within-group differences.

Results: CB resulted in significantly higher shade difference at 15 days recall (ΔVC and ΔeVS, all p ≤ 0.046). At 6 months recall, CB group demonstrated higher ΔeVS compared to IOB (p = 0.018) but the difference was not significant between the same groups when using VC (p = 0.051). Significant colour improvement was observed among all groups at 6 months recall (all within-group p < 0.001) except older participants (≥40 years) who received HB (ΔeVS: within-group p = 0.060). Overall, self-perception of oral health and satisfaction with smile and whiteness of teeth were significantly improved in all groups (all within-group p ≤ 0.001). Satisfaction levels with straightness of teeth were significantly improved for CB and IOB overall and in younger (<40 years) participants (all within-group p ≤ 0.013).

Conclusion: CB treatment resulted in a pronounced colour improvement when compared to both techniques used individually. All bleaching protocols resulted in significant improvement of participants' perceived oral health and satisfaction with smile and whiteness of teeth.

Clinical Significance: Accelerated whitening can be achieved using a combination of in-office and home bleaching. Patients who may accept gradual whitening of teeth can be treated effectively using a cost-effective protocol and less concentrated bleaching agents.