Methods: Twenty-one patients having discolored teeth due to trauma were included in the study. The shades of the adjacent teeth and discolored teeth were recorded by three clinicians with a value oriented shade guide (Vita Zahnfabrik). Bleaching treatment was performed with 35% hydrogen peroxide gel (Opalescence® Xtra, Ultradent). Two weeks later, the shade of the bleached tooth was recorded. Eighteen months later, dental examination of the patients was conducted and the shade of the bleached tooth was recorded again. Photographs were taken in all these steps. Data were analysed statistically by using Friedman and Wilcoxon Signed Ranks test.
Results: It was determined that the discolored tooth of the shades in each subject had been significantly different from those of the adjacent ones (p=0.0167). Two weeks after the bleaching treatment, it was determined that the shades of the 14 (67%) teeth had been the same as those of the adjacent ones and that the shades of the 7 (33%) teeth had been darker than those of the adjacent ones (p=0.0167). After 18 months, it was revealed that the shades of (71.4%) teeth had remained stabilized and the shades of (28.6%) teeth displayed rediscoloration (p=0.0167).
Conclusions: The office bleaching treatment carried out with 35% HP in one visit in order to remove the discoloration occurred through the devitalization of the tooth has demonstrated more advantages. In bleaching treatments, it is important to reduce the percentage of the rediscoloration to a minimum degree.