ID : 3304 Congress : 12 th International Congress of Iranian Academy of Restorative Dentistry 24 - 26 October 2012 Tabriz - Iran

Aim: This randomizes clinical trial evaluated of color change, rebound effect and tooth sensitivity associated with power and at-home bleaching techniques. Methods and Materials: Anterior teeth of twenty volunteers were randomized into two balanced groups (n=20) ; Power and at-home bleaching. Color was recorded before bleaching ,immediately after bleaching, at two weeks, one, three and six month intervals. Tooth sensitivity was recorded using the Visual Analog Scale .Bleaching effectiveness (∆E1) and Rebound effect (∆E2) were measured using Repeated Measures Analysis of Variance and Mann-Whitney tests respectively. Friedman test and Wilcoxon Signed-rank were used to compare ∆E within each group. Distribution of sensitivity was evaluated using Chi-square test (α=0.05). Results: There was no difference between techniques (P>0.05). Even though a significantly high degree of rebound effect was obtained with power bleaching, after six months the teeth remained significantly lighter than unbleached teeth (P<0.0%). Mild tooth sensitivity was observed but disappeared after two weeks. The distribution of sensitivity was identical with both techniques (P>0.05). Conclusion: Bleaching techniques resulted in identical tooth whitening and postoperative sensitivity, a greater regression of the whitening was found with the power bleaching. However, the residual whitening effect following both bleaching procedures could still be observed clinically.