Clinical evaluation of bleaching effect of 3% hydrogen peroxide strip with primer on human enamel

Objectives : The purpose of this study was to evaluate the bleaching effect of 3% hydrogen peroxide containing strip with primer in vivo. Methods : 22 female subjects aged from 20 to 39 years old were recruited after informed consent. They were divided into two groups with control and experimental group. Experimental group was bleached with 3% HP strip with primer, and control group received placebo for 14 days. Color changes were measured with Shade Eye-NCC (Shade Eye-NCC, SHOFU Co., Japan), Shade guide (VITA classical shade guide, VIDENTTM , CA, USA) and digital camera image. All collected data were analyzed using SPSS 18.0. Results : At baseline, L^* was 71.75±3.2 and b^* was 14.90±3.6 in control, and L^* was 71.3±3.4 and b^* was 15.61±3.7 in experimental group. At day 14, L^* was 71.35±3.2 and b^* was 13.97±4.3 in control, and L^* was 73.51±2.0 , b^* was 9.10±3.0 in experimental group. ΔE^* of all teeth were statistically significant between the two groups. Final ΔE^* was 7.15±2.09 at experimental group and 2.78±2.93 at control group, and the difference was significant (p<0.005). Color changes using shade guide also significantly decreased at 14th day compared with baseline at experimental group (p<0.005). Conclusions : 3% hydrogen peroxide strip with primer revealed effective enough to bleaching the human enamel during 14 days without any soft and hard tissue irritations.