Clinical Study to Compare Two Different At-Home Whitening Systems

Objectives: The aim of this clinical study was to compare the whitening efficacy of two at-home whitening systems: a liquid whitening gel (5.9% hydrogen peroxide) and a whitening gel applied in a tray system with a separate activator agent. The activator (sodium chlorite) is able to produce oxygen comparable to hydrogen peroxide. Methods: The study was an examiner blind, parallel grouped, randomized clinical trial. Sixty subjects with minimum baseline shade of A3 (Vita shade guide) on at least one of the upper six front teeth signed a study consent form and received a supragingival prophylaxis. The subjects were randomly divided in two groups (n=30 each) and instructed to bleach only the six maxillary anterior teeth. Daily contact time was for the liquid whitening gel (1) twice a day 15 min over two weeks and for the tray system (2) twice a day 10 min over three weeks, following the manufacturers' instructions. Efficacy was measured subjectively using the Vita shade scores obtained at baseline and after 2 weeks (1 and 2) and 3 weeks (2) of product use. Statistical analysis were carried out using covariance analysis. Results: The results showed that after two weeks the subjects teeth in group 1 exhibited a 1.0078 mean tooth-shade improvement compared to baseline and the subjects' teeth in group 2 exhibited a 0.569 mean tooth-shade improvement. After three weeks the subjects teeth in group 2 exhibited a 0.4713 mean tooth-shade improvement. The mean score in group 1 was 0.4388 units higher (p=0.29) after two weeks and 0.5365 units (p=0.19) after three weeks than the corresponding mean scores of the group 2. Conclusions: It can be concluded that (regardless of the application time) the use of a hydrogen peroxide liquid whitening gel (5.9%) for two weeks is clinically superior to a sodium chlorite based whitening gel.