The difference of bleaching effect between TiON and Opalescence in vivo

Objectives: The aim of this study was to evaluate the bleaching characteristics of two bleaching agents in vivo.
Methods: Sixteen patients obtained informed consent, 5 males and 11 females, attended in this study. Maxillary central incisor tooth were bleached using by TiON (Ti, GC, Japan) or Opalescence BOOST PF40% (OP, Ultradent, USA) according to the manufacturer's instructions and repeatedly bleached after a week, 8 participants respectively.
Tooth color was measured at the center area on the labial surface of the central incisor at 0, 7, 14, 30, 60, 90, 180, and 360 days with a dental spectrophotometer (Crystaleye CE100-DC/JP, Olympus). The color differences of the tooth, ΔE, were calculated on the basis of the before treatment. The data were analyzed by One-way ANOVA and Student-Newman-Keuls test (p<0.05).
Results: At 0 day (before the 1st bleaching), the (L*, a*, b*) of the tooth were (72.9±3.0, 1.5±0.8, 18.1±3.2) for Ti group and (71.3±3.4, 1.1±1.2, 17.9±3.1) for OP group.
At 7days (immediately after the 2nd bleaching), the (L*, a*, b*) were (75.4±2.4, 1.0±0.8, 12.8±2.3) for Ti group and (73.9±4.4, 0.6±1.1, 13.8±3.8) for OP group.
At 360 days, the (L*, a*, b*) were (74.2±3.2, 0.6±0.6, 15.4±2.4) for Ti group and (73.6±4.4, 0.6±0.8, 15.4±2.0) for OP group.
The a* and b* values of Ti were significantly decreased at 7 days or later. And the b* values of OP was significantly decreased at 7 days or later.
For the color difference (ΔE) to the 0 day, Ti showed 6.1±2.3 at 7 days and 3.7±1.9 at 360 days and OP showed 5.1±3.6 at 7 days and 4.2±1.7 at 360 days. There were no significant differences between Ti and OP.
Conclusions: The results in the present study suggested that Ti and OP showed sufficient bleaching effects after 1 year.