Impact of the in-office bleaching gels pH on tooth sensitivity in combined bleaching techniques: a randomized clinical trial.

OBJECTIVES

This randomized, parallel, single-blind clinical trial evaluated tooth sensitivity (TS), efficacy, gingival irritation (GI), aesthetic self-perception, and psychosocial impact of combined bleaching using in-office bleaching agents with different pHs.

MATERIALS AND METHODS

160 participants were randomized into two groups (n = 80) with 35% hydrogen peroxide in-office bleaching gels: Whiteness HP Maxx (acidic, unstable pH) and Whiteness HP Automixx Plus (neutral, stable pH). In-office bleaching was performed in one session: HP Maxx (3 applications of 15 min) and HP Automixx Plus (1 application of 50 min). Both groups then received at-home bleaching with 10% carbamide peroxide for 4 h daily for two weeks. TS and GI were assessed using Visual Analogue Scales. Color change was measured with a spectrophotometer and color guides. Aesthetic self-perception and psychosocial impact were evaluated using three scales: Orofacial Aesthetics Scale, Oral Health Impact Profile, and Psychosocial Impact Questionnaire of Dental Aesthetics.

RESULTS

The risk and intensity of TS significantly favored the neutral and stable pH gel for both in-office (p < 0.001) and combined treatments (p < 0.004). Both groups achieved significant whitening (p > 0.37). No difference in GI risk or intensity was found (p > 0.11). All aesthetic and psychosocial scales showed significant improvement post-treatment (p < 0.05).

CONCLUSION

Using a gel with neutral and stable pH during in-office bleaching reduces the risk and intensity of TS without compromising whitening efficacy.

CLINICAL RELEVANCE

Combining at-home and in-office bleaching with a neutral, stable gel reduces TS risk and intensity while ensuring optimal whitening results and patient comfort.