The evaluation of in vitro effectiveness of various types of sodium perborate and sodium percarbonate on the bleaching of devital teeth which are stained artificially

SUMMARY Regaining of natural teeth esthetics is one of the most important aims of dentistry. It is tried to remove teeth discoloration which causes esthetic problems and to protect teeth and gum with the conservative technics applied today. As a result of the studies of restorative dentistry on the way of this aim, various bleaching technics and materials are improvised. This research is conducted in order to evaluate the effectiveness of various sodium perborate and sodium percarbonate on the bleaching of devital teeth which are stained artificially. Our study is accomplished on the 60 anterior teeth without cavities and restoration which extracted for periodontal and orthodonic reasons. The standart lingual entrance cavities of teeth, which are removed a level 3 mm below the cementoenamel junction, were prepared. The canals of all teeth were enlarged with gates glidden burs and their natural colors were established with the dental colorimetry apparatus. The teeth which were filled with human hemoglobine and put in test tubes, were centrifuged for 3 days. After determining the beginning L* values of discolorated teeth, they were seperated into four equal groups, 15 teeth for each group by using different bleaching material for each group. For the first group Sodium perborate + %35 H2O2, for the second group Sodium perborate + %3 H2O2 materials, for third group Sodium percarbonate + %35 H2O2 and for fourth group Sodium percarbonate + %3 H2O2 materials were put in order according to the proposals of producer firms. The L* brilliance values of all teeth at 3., 7., and 11. days were registered by using CIELAB color analysis system. The datas, which had been recorded by measures, were appraised statistical by using One Way Anova Analysis and Tukey HSD test. Among these four different types of materials; first group mixture became the most bleaching effectiveness, then second, third and fourth groups' mixtures followed it respectively. Key Words: Bleaching effectiveness, nonvital bleaching, sodium perborate, sodium percarbonate.