“Evaluation of Tooth Color Change for In-office and At-home Bleaching"

Objective: This in vitro pilot study evaluated tooth color change for two in-office bleaching systems: (35% and 25% hydrogen peroxide) used with and without light activation and a home tray system using 10% carbamide peroxide. Methods: Eighteen intact, non-carious human maxillary central incisors were randomly assigned to 6 groups: ZOOM!, 25% hydrogen peroxide (Discus Dental) with (G1) and without (G2)) light activation, Luma Arch, 35% hydrogen peroxide, (Lumalite), with (G3) and without (G4) light activation, Nite White Excel, 10% carbamide peroxide (Discus Dental) (G5) and control group, stored in artificial saliva (G6). Teeth were mounted using polyvinylsiloxane with roots immerged in water. Specimens were stored in artificial saliva at 37ºC and 100% humidity between bleaching treatments. Data was recorded as L*a*b* (CIE) using a Minolta CR-221 chromameter. Shade measurements were taken at baseline and after 2 weeks or sessions of bleaching. Color change was determined using the equation ;[DEab=((DL)² + (Da)² + (Db)²)^1/2]. Repeated-measures analysis of variance was used to evaluate differences among groups (a=0.05). Tukey’s HSD was used for pair wise comparisons. Results: Evidence of treatment differences in DL* at week 2 (p=0.01) existed. The greatest change in lightness occurred with 10% carbamide peroxide (mean DL* =11.85). This was not significantly different from ZOOM! (mean DL* =4.00) or Luma Arch (mean DL* =4.43) with light activation, but was significantly greater than ZOOM! (mean DL* =1.66) and Luma Arch (mean DL* =2.42) without light and the control (mean DL* =2.50). Conclusion: In this pilot study home bleaching did not appear to be superior to in-office bleaching with light. However more specimens are required to determine the validity of statistical and/or clinical significance.