ABSTRACT
In this study the efficacy of various intracanal barrier materials in preventing the leakage of bleaching agents into the coronal part of the root canal were evaluated. Forty extracted single root human teeth were used. The root canals were prepared and filled. The teeth were divided into three experimental groups. Three barrier materials (Ketac Molar, Filtek Z250 and Adhesor) were applied. All teeth were bleached with a mixture of sodium perborate and hydrogen peroxide 30%, and they were stored in methylen blue 2% for 5 days. Each tooth was sectioned longitudinally. Linear dye penetration was measured in milimeters. When compared with Z250 and with Adhesor, it has been determined that Ketac Molar Easymix produces less leakage (p<0.05). No statistical differences were found between Adhesor and Z250 (p>0.05).