Color change with two commercial tooth whiteners and a placebo

Objective: Color change was compared for two commercially available whiteners and a placebo. Methods: Participants in groups NWA (Nite White ACP 16%; Discus Dental), OPF (Opalescence PF 15%; Ultradent) and P (placebo; carrier gel without active ingredient) used assigned materials nightly for two weeks. Color evaluations were at baseline (E1), and one (E2), two (E3) and eight weeks (E4). Color was measured using an intra-oral spectrophotometer and two shade guide (Vita Classical=VC; modified Classical=MVC). MVC was ordered using L* values, and used 10 VC tabs chosen to eliminate equivalent pairs. For VC and MVC the baseline tab number was subtracted from subsequent evaluations. Delta e 2000 (De 00) from baseline to was calculated using LCH. Color change for each tooth was calculated and the average for study teeth calculated at each evaluation. This was the primary outcome.

Results: Following are color differences at E4. For VC: NWA=5.3, OPF=6.4 & P=1.3. For MVC NWA=2.5. OPF=3.0 & P=0.23. For De00: NWA=4.5, OPF=4.8 & P=2.2. Following are baseline and E4 data: For L* NWA= 75.0, 78.6; OPF= 74.6, 78.0; P= 72.2, 72.0. For C* NWA= 21.2, 16.1; OPF= 21.0, 15.6. P = 22.0, 22.1. For H* NWA= 92.1, 97.9; OPF= 91.5, 98.0. P= 89.8, 89.0. For NWA and OPF, a significant increased in L* and decrease in C* were observed (p<0.002). NWA and OPF were associated with significantly more whitening than P at all evaluations (p<0.001). There was no difference between NWA and OPF at any evaluation. The tab difference for NWA at E4 was significantly lower than at E3 (p<0.007). For OPF there was no significant difference between E3 and E4. (p<0.001; RM ANOVA all tests). Conclusion: Overall whitening was equivalent. For NWA, there was a significant loss of color change six weeks post-bleaching. Supported by Ultradent Products, Inc.