Bleaching effect of activation of hydrogen peroxide using photon-initiated photoacoustic streaming technique.

Objectives: This study aims to investigate the bleaching effectiveness of photon-initiated photoacoustic streaming (PIPS) using 35 % hydrogen peroxide on discolored teeth as compared with different devital bleaching techniques.

Materials And Methods: Fifty extracted human mandibular incisors were collected and artificially stained using sheep's blood. The teeth were then randomly divided into five groups according to the different bleaching procedures to be tested: walking bleach with sodium perborate and with 35 % hydrogen peroxide gel, both for 1 week; PIPS using 35 % hydrogen peroxide liquid for 30 min; and just 35 % hydrogen peroxide, as a liquid and as a gel (again, for 30 min). Spectrophotometric measurements were obtained on the buccal surfaces of the crowns, at the beginning, just after the bleaching procedures had been performed, and the following first, third, and seventh days. The ∆E values were calculated, and the data were analyzed with a two-way analysis of variance (P = 0.05).

Results: There were statistically significant differences between the PIPS technique using 35 % hydrogen peroxide liquid and the 35 % hydrogen peroxide liquid and gel without PIPS immediately after the procedures (P < 0.05). On Days 1, 3, and 7, the PIPS technique further bleached specimens more than all of the other techniques (P < 0.05).

Conclusions: The PIPS technique using 35 % hydrogen peroxide was found to be more effective than all of the conventional techniques.

Clinical Relevance: Within limitations of this study, PIPS technique using hydrogen peroxide was superior to the conventional techniques. Further studies should be conducted to determine if the PIPS technique results in any complications, particularly cervical resorption.