Impact of microabrasion and a remineralizing agent before in-office bleaching on hydrogen peroxide permeability, color alteration, and enamel morphology.

OBJECTIVE

This in vitro study evaluated hydrogen peroxide (HP) penetration into the pulp chamber, bleaching efficacy, and surface enamel morphology of human teeth subjected to enamel microabrasion (MA) combined with in-office bleaching (IOB), with or without the application of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) remineralizing agent.

METHODS

Forty sound premolars were randomly divided into four groups: no treatment (NT), IOB only (IOB), MA followed by IOB (MA+IOB), and MA followed by CPP-ACP and then IOB (MA+CPP-ACP+IOB). HP concentration in the pulp chamber was measured using UV-Vis spectrophotometry, while bleaching efficacy was assessed with a digital spectrophotometer. Surface morphology was analyzed using scanning electron microscopy (SEM), and data were statistically analyzed.

RESULTS

The NT group exhibited lower HP penetration compared to experimental groups, while MA+IOB showed higher HP levels than IOB and MA+CPP-ACP+IOB. All experimental groups demonstrated significant color changes, except NT. The MA+IOB group displayed more grooves on enamel surfaces than the MA+CPP-ACP+IOB group, which had remineralizing agent deposits.

CONCLUSION

Combining MA and IOB increases HP penetration into the pulp chamber, but using CPP-ACP after MA can mitigate this effect without compromising bleaching efficacy.

CLINICAL SIGNIFICANCE: Employing a CPP-ACP remineralizing agent post-microabrasion can help reduce HP levels in the pulp chamber while maintaining effective whitening.