Purpose: The purpose of this study was to evaluate changes in calcium and phosphorus content in dental enamel when subjected to "in-office" whitening for an extended time by using a 35% hydrogen peroxide solution, with and without calcium.
Materials And Methods: 10 human teeth, from which the roots had been removed, were embedded in epoxy resin, and their surfaces were smoothed. The specimens were divided into two groups; in group 1, a whitening solution without calcium was used, while in group 2, the solution included calcium.