Effect ofTwo Bleaching Regimens onThe Color ofTooth Colored Restoratives

Objectives: The purpose of this invitro study was to compare the color changes of five different tooth colored restoratives; Ormocer (Definite/ Degussa), compomer (Dyract AP/ Dentsply De Tray), packable composite (Filtek P60/ 3M), flowable composite (Filtek Flow/ 3M) and hybrid composite (Filtek Z250/ 3M) after two different bleaching regimens (Vivastyle/ Vivadent and Crest Professional Whitestrips/ Procter & Gamble). Methods: Fifteen specimens 30x30x2 mm size were fabricated from each material and randomly divided into three groups of five. Specimens in group one were stored in distilled water at 37¢ªC for two weeks and served as control. Group two specimens were treated with 10% carbamide peroxide (Vivastyle) for two hours per day for two weeks and group three specimens were treated with 6.5% hydrogen peroxide strip bands (Whitestrips) for 30 minutes twice daily for two weeks. During the test period the specimens were kept in at 37¢ªC and 100% relative humidity. At the end of the bleaching regimens color measurements of the control and test groups were made with UV visible recording spectrophotometer. Color change were calculated with the use of the CIE-LAB uniform color scale and compared by the use of Kruskall-Wallis test, followed by the Mann-Whitney U test. Results: L*, a*, b* values of restorative materials were found to be significantly different except Filtek Z250 among control, Vivastyle and Whitestrips groups (p<0.05). All restorative materials demonstrated significantly higher color change (¥ÄE) with Whitestrips (p<0.05). Dyract AP demonstrated highest color change by both bleaching regimens application followed by Filtek Flow, Definite, Filtek P60 and Filtek Z250 showed the least color change. Conclusion: As tooth colored restorative materials exhibited different color changes with bleaching this characteristic should be considered before bleaching treatment.