Purpose: Vital tooth bleaching has become a popular procedure for whitening teeth. Most home bleaching products contain 10% carbamide peroxide. The purpose of this in vitro study was to measure the quantity of hydrogen peroxide that reaches the pulp chamber from three carbamide peroxide products: OpalescenceTM, SparkleTM, and RembrandtTM. Materials and Methods: Seventy roots of extracted premolars were amputated approximately 3 mm apical to the cementoenamel junction, and the pulp tissues were removed. They weredivided into three experimental groups (n = 20) and a control group of 10 teeth. An acetate buffer solution was placed in the pulp chamber before the crown was exposed to the bleaching agent at 37°C for 25 minutes. The buffer solution was removed and reacted with leuko crystal violet and horsera dish peroxidase. The optical density of blue colour that developed was measured at a wave length of 596 nm and read from a standard curve for hydrogen peroxide quantity. Results: The measured amounts of hydrogen peroxide were 3.605 = 1.405, 1.282 = 0.762, and0.339 f 0.251 µg for the OpalescenceTM, SparkleTM, and RembrandtTM groups, respectively. A statistically significant difference in the hydrogen peroxide levels was observed by analysis of variance (p <.05) among the three groups. Conclusion: It was concluded that the penetration of commercial bleaching products was different even though the products were labelled as having the same 10% carbamide peroxide.
Key words: Carbamide Peroxide, tooth bleaching, vital tooth.