DEMINERALIZATION EFFECTS OF 10 PERCENT CARBAMIDE PEROXIDE

Objectives: The purpose of this in vitro study was to measure the amou nt of calcium lost from enamel exposed to a 10% carbamide peroxide sol ution. Methods: Nine teeth (3 incisors, 2 premolars, 4 molars) were se ctioned to serve as paired test and control specimens. Each tooth half was coated with wax, leaving a uniform 3 mm x 4 mm window of exposed enamel. Test specimens were placed in culture tubes with 1.00 ml of de ionized water and 0.02 ml of 10% carbamide peroxide for 6 h; controls were exposed to water alone. Calcium concentrations in the spectrophot ometer. solutions were measured using a Perkin-Elmer 5100 atomic absor ption spectrophotometer. Results: Teeth exposed to carbamide peroxide lost and average of 1.06 mu g/mm(2) of calcium. This amount of loss wa s significantly greater than controls (p < 0.001), according to ANOVA. For comparison, teeth were exposed to a cola beverage for 2.5 min, th e time equivalent of drinking a 16 oz. beverage. The amount of calcium lost from these teeth was also about 1 mu g/mm(2). Conclusions: Teeth exposed to 10% carbamide peroxide lost calcium. However, the amount o f loss was small, and may not be clinically significant. Copyright (C) 1996 Elsevier Science Ltd.