Color and Light Transmittance Characteristic of Light-cured Resin Composites

Objectives: Color and translucency of the natural dentition should be simulated in order to create optimal esthetic dental restoration. Composite resin materials attempt to restore the color and appearance of natural teeth. However, current composite resin systems display various color and degree of translucency. The purpose of this study was to characterize color and the translucency of 5 resin composites. Methods: Composite resin(A3 Shade) disks with diameters approximately 8mm were made by injecting materials onto a silicone coated glass slide and flattened to 1 mm with another silicone coated glass slide and light cured for 40 seconds. The resin disks(5 samples for each resins) was measured in CIE L*a*b* coordinates using a spectrophotometer (PR-650, Photo Research) over white and black backgrounds. Contrast ratio(CR) were then compared. Results were analyzed using Tukey's. Results: Mean color and contrast ratio values (L*(SD):a*(SD):b*(SD):CR(SD) ) were: SI-R20402G(SHOFU) 81.90 (0.22): 5.57(0.11) : 31.83 (0.40) : 53.55 (0.64), Esthet-X (DENTSPLY) 86.36 (0.21) 3.42 (0.24) 37.72 (0.53) 56.17 (0.87), ICE(SDI) 82.83 (0.71) 6.91 (1.05) 40.60 (2.26) 56. 59(0.77),Charisma(HERAEUS KULZER) 87.71 (0.39 ) 1.23( 0.14) 28.86 (0.64) 45.53(0.79), Solare(GC) 86.27 (0.42) 2.56 (0.08) 32.45 (0.70) 48.33 (0.51) CR values were significant differences in all composites without Esthet-X and ICE(P<0.01). Conclusion:Values of CR of composite with the same shade designation were not always the same. Shade designations were sometime misleading.