In-office bleaching with a commercial 40% hydrogen peroxide gel modified to have different pHs: Color change, surface morphology, and penetration of hydrogen peroxide into the pulp chamber.

Objective: In-office bleaching gels are usually marketed in different pHs. This study is aimed at evaluating the efficacy, enamel surface morphology and concentration of hydrogen peroxide (HP) in the pulp chamber of teeth bleached with 40% HP with different pHs.

Materials And Methods: Forty premolars were randomly divided according to bleaching gel pH: 5.