Objective:

To analyze changes in phosphate molecules in dental enamel after application of in-office dental bleach at different concentrations and type of activation.

Material and methods:

30 recently extracted, human teeth free of caries and pigmentations were randomly distributed into three experimental groups. Tooth whitening materials used in each experimental group were Zoom! WhiteSpeed (group 1), Pola Office with light-activation (group 2) and Pola Office without light activation (group 3). Bleaching agents were applied according to manufacturer’s instructions; two applications on the first sessions and one application in the second session. With Raman spectroscopy phosphate v1 molecule concentration was measured in tooth enamel before treatment and after each bleaching session. ANOVA variance analysis was used for repetitive measurements (p ≤ 0.05); Bonferroni post hoc test was used for comparisons between treatment sessions and control week.

Results:

All three in-office bleachers elicited increase in phosphate v1 molecule concentration during bleaching process (p ≤ 0.05), Pola Office, with both types of activation caused significant phosphate increase during the whole treatment. Zoom! WhiteSpeed showed significant increment with respect to control week, but did not show increase between first and second session (p ≤ 0.05).

Conclusions:

Within the scope of this study’s limitations, it is possible to conclude that all three studied in-office bleaching agents increased phosphate v1 molecule. Activation type did not elicit significant difference.