Effect of Restoration Depth and Thermocycling on Color Matching of a Smart Single Shade Universal Resin Composite with the Surrounding Hard Dental Tissues

Abstract

Objective: To determine the shade matching ability of a single-shade universal composite with the surrounding hard dental tissues at different cavity depths and after thermocycling. Materials and Methods: Ninety extracted premolars were selected and Class V cavities were then prepared and teeth were divided in to 3 groups according to cavity depths; Group 1: 1 mm cavity depth, Group 2: 2 mm cavity depth and Group 3: 3 mm cavity depth. Specimens were restored with an Omnichroma shade matching composite and stored in distilled water at 37° C for 24 h. Subsequently, each group was subdivided in to 3 subgroups according to thermocycling protocols as follow; subgroup A not thermocycled (as control), subgroup B aged by 5000 TC and subgroup C aged by 10000 TC. Shade evaluations were recorded using the digital spectrophotometer. The color data were statistically analyzed, and was considered statistically significant at P = 0.05. Results: There was no significant difference in the L*a*b* values between the restoration and tooth for all groups and subgroups (P > 0.05). Color differences (∆E) were significantly higher at restorations with 1 mm cavity depth than that with 2 mm and 3 mm cavity depths (P < 0.05). On contrary, thermocycling led to significant color changes (P < 0.05), compared to control group. Conclusion: Omnichroma single-shade universal composite is good alternative for color-matched, esthetically satisfying restorations. Restoration depth was positively associated with shade matching ability, while thermocycling negatively affected it.