Evaluating the efficiency of two different over-the-counter tooth whitening systems: a randomised controlled clinical trial.

Objectives: To compare whitening efficiency and tooth sensitivity (TS) of two different over the counter (OTC) whitening systems in comparison to conventional at-home bleaching using 20% carbamide peroxide.

Materials and methods: A randomised controlled clinical trial was conducted with three parallel groups (n = 13): (A) at-home whitening using 20% carbamide peroxide (20% CP), (B) OTC ready-to-use gel trays and (C) OTC-paint on gel. Clinical colour change values (ΔE) were measured using spectrophotometry at T0: baseline, T1: 7-day and T2: 14-day from whitening start, T3: 2 weeks and T4: 6 months after whitening end. TS was recorded using a visual analogue scale (VAS). ΔE and TS values were statistically analysed. The level of significance for all tests was 5%.

Results: Significant differences in ∆E values were recorded between the experimental groups. ∆E values were significantly higher in the 20% CP conventional at-home whitening group. TS measurements were significantly higher in the 20% CP whitening group (p < 0.05).

Conclusion: Conventional at-home whitening revealed significantly improved colour change when compared to the OTC-paint on gel and OTC ready-to-use gel tray whitening systems. There was a significant colour relapse in OTC systems.

Clinical relevance: The use of tested OTC systems is not recommended as they are not effective in a clear and prolonged improved shade change. Conventional at-home whitening using 20% CP showed higher whitening efficiency and colour stability. This trial was registered with a International Standard Randomised Controlled Trial Number (ISRCTN23096480), Registration date: 12/04/2023.