ROLE OF CATALASE IN THE ELIMINATION OF RESIDUAL HYDROGEN-PEROXIDE FOLLOWING TOOTH BLEACHING

Hydrogen peroxide at high concentrations may cause damage to the tooth structure and to the surrounding periodontal tissues. The efficacy of catalase applied following intracoronal bleaching to eliminate residual hydrogen peroxide was examined and compared with prolonged water rinses. Extracted human premolars were treated endodontically and bleached with 30% hydrogen peroxide. Upon completion of the bleaching procedure, the teeth were treated with either catalase or water. Radicular hydrogen peroxide penetration was measured immediately after bleaching and following each catalase and/or water rinse. A correlation between the number of water rinses and the reduction in the radicular hydrogen peroxide penetration was found. Three cycles of 5-min water rinses and 1-h immersion of the teeth in water significantly reduced the residual hydrogen peroxide penetration. One treatment with catalase applied for 3 min totally eliminated the residual hydrogen peroxide. It is therefore suggested that catalase be used as an adjunct following intracoronal bleaching of nonvital teeth to effectively eliminate the residual hydrogen peroxide from the pulp chamber and from the surrounding periodontal tissues.