ABSTRACT
This chapter provides an overview on safety issues in tooth bleaching in relation to biologic properties of hydrogen peroxide and discusses proper use of bleaching to maximize the benefits while minimizing the potential risks. A key characteristic of hydrogen peroxide is its capability of producing free radicals, which are known to be capable of inducing various toxicities, including hydroxyl radicals that have been implicated in various stages of carcinogenesis. Chemically, carbamide peroxide is composed of approximately 3.5 parts of hydrogen peroxide and 6.5 parts of urea, so a bleaching gel of 10% carbamide peroxide contains approximately 3.5% hydrogen peroxide. Potential systemic toxicity of hydrogen peroxide and peroxide-based tooth bleaching gels has been the subject of a comprehensive body of literature, which includes topics of acute and subacute systemic toxicity, sensitization or allergic reaction, reproductive toxicity and teratology, genotoxicity, and carcinogenicity. Subacute systemic toxicities of hydrogen peroxide and peroxide-based tooth bleaching gels have been investigated in animals only.
