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

Purpose. To evaluate the bleaching efficacy and erosion potential of various over-the-counter bleaching products following a test method specified in ISO 28399. Methods: 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 (&epsi;Ra), 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 Friedmantest and stratified by hard tissue type with a= 0.05. Results: WS was the only group demonstrating color changes in enamel and dentin (P< 0.05). There were no differences in ARa for enamel and dentin among NC, BT, LP, and WS. NW showed increase in ARa in dentin (P< 0.05), while PC demonstrated an increase in ARa regardless of hard tissue type (P< 0.05).