The pH of tooth-whitening products.

Tooth whitening products may be in contact with intraoral structures for several hours or they may be used daily to whiten the teeth. Consequently, these products should have a relatively neutral pH to minimize potential damage. This study measured the pH of 26 commercially available tooth-whitening products. The pH of the different whitening products ranged from 3.67 (highly acidic) to 11.13 (highly basic). The dentist-supervised home-bleaching products had a mean pH of 6.48 (range 5.66 to 7.35). The over-the-counter whitening products had a mean pH of 8.22 (range 5.09 to 11.13), and the whitening toothpastes had a mean pH of 6.83 (range 4.22 to 8.35). The 3 in-office bleaching products had a pH between 3.67 and 6.53. One-way ANOVA showed that there was a significant difference between the 4 product categories. The most basic pH of all the products tested was 11.13 for the whitening gel of Natural White-Rapid White. The most acidic pH of all products tested was 3.67 for Opalescence Xtra 35% hydrogen peroxide in-office bleach. The Least-Squares-Means test showed that the over-the-counter category had a pH significantly different from the other categories (p < 0.05).