Clinical Evaluation of Shade Improvement after In-office Vital Bleaching

Objectives: To evaluate the degree of colour change after in-office vital tooth bleaching with 35% hydrogen peroxide gel using a spectrophotometer. Methods: The maxillary anterior teeth of 22 patients comprising of 11 males and 11 females were bleached with a 35% hydrogen peroxide gel (Yotuel® Special, Biocosmetics Laboratories, Spain). All patients signed a consent form before starting the treatment. Pre-treatment readings of the two maxillary central incisors were obtained using a spectrophotometer (CM-2600d Konica, Minolta). Subsequent readings were obtained after scaling and polishing, before bleaching (which was used as a baseline reading), immediately after bleaching, one week and one month post-operatively. Patients were requested to complete a form regarding post-operative tooth sensitivity and their colour perception toward the bleaching treatment. Results: The quantitative effect of the bleaching material on tooth colour showed an increase in L* values and a decrease in a* and b* values, the changes were significant (Wilcoxon Signed Rank Sum Test; p<0.05) from baseline till one month, except for b* which was only significant between five and ten percent after one month. The median overall colour change (ΔE) between baseline and after bleaching was 3.56. Tooth sensitivity was traced till the fifth day after bleaching. The mean value of patients' colour perception was found to be 2.14 immediately after bleaching on a 3 point visual analogue scale. Conclusion: Yotuel® Special 35% HP was able to bleach patients' teeth with a perceptive colour change noticeable by the patients; however colour regression was evident quantitatively from the first week. Tooth sensitivity was a temporary side effect.