In vitro comparison of bleaching agents on the crowns and roots of discolored teeth.

Sixty teeth were stained in vitro to compare the decolorizing effect of three bleaching agents on the crowns and on the roots of teeth containing an intracoronal isolating base. With an intracoronal isolating base placed either at the cementoenamel junction (CEJ) or 2-mm below the CEJ, bleaching agents of Superoxol, sodium perborate, and a combination of the two were placed in the pulp chamber of teeth and the accesses sealed with IRM. Customized shade guides were used to evaluate the color changes of the crowns and roots. After three treatments, the combination technique was found to be more effective in decolorizing the crowns and roots of teeth than Superoxol or sodium perborate alone (p less than 0.05). No difference was found between the Superoxol group and the sodium perborate group. There was no difference in color shades of crowns in which the IRM base was placed either at the CEJ or 2-mm below the CEJ. The roots of all groups showed some degree of decoloration. Based on the bleaching effects on discolored roots, the effectiveness of this seal is questionable.