Tooth color changes and sensitivity in patients undergoing dental bleaching with 10% hydrogen peroxide using customized trays or strips: a randomized clinical trial

BACKGROUND: This paper aimed to compare the tooth color changes and sensitivity in patients undergoing dental bleaching with 10% hydrogen peroxide using customized trays or strips as delivering systems. METHODS: A total of 50 patients aged between 18-30 years old were assigned into two groups (N.=25) according to the bleaching treatment: tray (TB) or strips (SB). For both techniques, the patients underwent a 30-minute application of 10% hydrogen peroxide twice a day for seven days. Tooth color was evaluated before, 3 and 7 days of treatment, and 14 days after bleaching using a tooth color shade guide (VITA (R) shade). Tooth sensitivity was assessed using the Visual Analogue Scale (VAS). The values obtained from the color changes and tooth sensitivity were statistically analyzed (alpha=5%). RESULTS: For both groups, there was a significant difference on the tooth color before and after bleaching (P<0.001), although there was no significant difference between them (P=0.4215). The SB group exhibited a lower frequency of sensitivity (50.2%) compared to the TB group (70.2%) (P<0.001). However, the highest number of individuals reporting score 1 of sensitivity was found in the SB group (37.3%) compared to the TB group (20.9%) (P<0.001). For the other scores, there were no differences between the SB and TB groups, with results of 9.8% and 8.4% for score 2 (P=0.744) and 2.7% and 0.5% for score 3 (P=0.122). CONCLUSIONS: The bleaching effect of 10% hydrogen peroxide is not influenced by the delivering system (tray or strips). Even though the technique with strips was associated to a lower frequency of dental sensitivity, the peak level of pain was greater when compared to the technique using trays.