Effect of bleaching agents on calcium loss from the enamel surface.

Objectives: To compare the Ca2+ loss of enamel treated with 38% hydrogen peroxide (HP), 35% HP with light, and 10% carbamide peroxide (CP).

Method And Materials: Ten extracted premolars were sectioned buccolingually and longitudinally so that 4 specimens were obtained from each tooth. The specimens were randomly assigned to 1 of 4 groups to receive the following bleaching agents: 38% HP, 35% HP with light, 10% CP, and no agent (control).