The effects of home-use and in-office bleaching treatments on calcium and phosphorus concentrations in tooth enamel: an in vivo study.

Background: Because the effects of dental bleaching on enamel needs to be clarified in vivo, the authors conducted a study to determine calcium and phosphorus concentrations in enamel after the application of different bleaching treatments.

Methods: The authors applied four agents (10 percent and 20 percent carbamide peroxide [both recommended for home use], 38 percent and 35 percent hydrogen peroxide [both applied in the dental office]) to the enamel of 80 participants, who were divided into four groups of 20. The authors collected enamel microbiopsy specimens from incisors before (baseline), during (seven, 14 and 21 days) and after (seven and 14 days) the bleaching treatments. They analyzed calcium and phosphorus concentrations by using a spectrophotometer.

Results: The authors analyzed data by using the Friedman test and the Kruskal-Wallis test, followed by the Dunn test (α= .05). There were no statistical differences between the evaluation results, regardless of which bleaching gel was used, for determining the concentration of either calcium or phosphorus.

Conclusions: Home-use and in-office bleaching gels did not alter the concentrations of calcium and phosphorus concentrations on the enamel surface in vivo.

Clinical Implications: In vivo, different dental bleaching techniques did not alter the inorganic composition of enamel.