Evaluation of bleaching efficacy and erosion potential of four different over-the-counter bleaching products

To evaluate the bleaching efficacy and erosion potential of various over-the-counter bleaching products following a test method specified in ISO 28399.

Specimens were prepared from bovine molars, stained in tea solution, embedded and randomly assigned to six groups of 10 enamel and dentin specimens each. Color was assessed at baseline, 1 day and 1 month post-bleaching with the Vita Bleachedguide 3D Master shade guide. Surface roughness changes (deltaRa), determined by baseline and post-treatment values were measured with a profilometer. The negative (NC) and positive control (PC) was treated with grade 3 water and 1.0% citric acid, respectively. Over-the-counter products were used according to manufacturer's instructions. Brite Teeth Pro (BT), Natural White 5-Minute Whitening (NW), Luster Premium White (LP), and Crest 3D Whitestrips (WS) represented a brush-on-paint system, tray system, light-activated system and adhesive-strip system, respectively. Kruskal-Wallis procedure was used to compare surface roughness changes among groups. Color change was assessed with Friedman-test and stratified by hard tissue type with alpha= 0.05.

WS was the only group demonstrating color changes in enamel and dentin (P< 0.05). There were no differences in deltaRa for enamel and dentin among NC, BT, LP, and WS. NW showed increase in deltaRa in dentin (P< 0.05), while PC demonstrated an increase in deltaRa regardless of hard tissue type (P< 0.05).