A water-soluble chemical compound (NaBO3) manufactured by the reaction between sodium tetraborate, hydrogen peroxide, and sodium hydroxide. It releases hydrogen peroxide when in contact with water and has antiseptic and bleaching properties. Because it is oxygen liberating it has been used in the treatment of necrotizing ulcerative gingivitis and the internal bleaching of pulpless teeth. In the latter case, sodium perborate is either mixed with water or 30% hydrogen peroxide to form a paste and then sealed in the pulp cavity for an extended period of time. Prolonged use of sodium perborate can lead to mucosal irritation and hyperplasia of the filiform papillae of the tongue (black hairy tongue) Trade name: Bocasan®.