Clinical evaluation on the efficacy of the Crest whitening strips

Objectives: This study was to evaluate the efficacy, safety and the whitening effect after one year usage of the Crest whitening strips. Methods: This was a single blind study. Ten volunteers were recruited into the clinical study and six persons were pursued after one year later. Photos were taken before the treatment, 7 days , 14 days and one year after the treatment by using Digital Imaging Analysis (DIA) equipment. At the same time, oral hard and soft tissues were examined for safety. Results: The results showed that after 7 days and 14 days treatment, the average b (yellowness) value decreased by 1.67 and 2.30; the average L value (brightness) increased by 1.42 and 2.05, the total color improved by 2.56 and 3.39, respectively. The evaluation conducted after one year showed that compared to baseline, the average L value (brightness) increased by 1.47(72% retained), the average b (yellowness) value decreased by 1.33(58% retained), and the total color improved by 2.46(73% retained). The treatment was well tolerated. Conclusions: These results demonstrated that the novel whitening strips containing 6% hydrogen peroxide had significant tooth whitening efficacy in both 7 days (14 strips) and 14 days (28 strips) usage, and it remained good whitening effect after one year. Novel whitening strip was well tolerated for daily usage.