Effects of in-office whitening on 3 areas of extracted teeth

Methods: Two types of office whitening product: Hi Lite (Shofu Co.) and PYRENEES (Morita Co.) were used. The experiment was performed using 10 extracted human teeth and were distributed into 2 groups of 5 each. Each whitening agent was applied 3 times per whitening treatment, and the whitening treatment was repeated 3 times following the manufacturer's instructions. Color (L^*a^*b^*) was assessed using a dental colorimeter (Shadepilot, Dentsply sankin Co.) and, statistical analysis were performed using two-way ANOVA and Tukey's t-test.

Results:Color difference ΔEab^* between before and after 3 whitening treatments were 5.04 in PYRENEES, and 3.71 in Hi Lite, in which the color differences with PYRENEES was significantly larger than that with Hi Lite. Color differences of 3 areas (ΔEab^*) were 5.67 (cervical), 5.00 (body), 4.58 (incisal) in PYRENEES. Significantly differences were noted in color differences each 3 areas in PYRENEES, but were not in Hi Lite. Hi Lite were not significantly different. The color difference became more marked as the treatment frequency increased. The difference after the third treatment was significantly greater than that after the second treatment.

Conclusions: It was revealed that PYRENEES and Hi Lite were clinically effective as whitening materials. Whitening effects were higher with PYRENEES than with Hi Lite. Cervical area showed the highest color difference among other areas in PYRENEES.