Effect of Artificial Accelerated Aging on Color Stability and Surface Roughness of Indirect Composites

Abstract - Direct and indirect composite resins have different forms of polymerization. Some materials require a postcure system associating light and heat enhancing clinical properties. This study assessed the changes in color and surface roughness of three indirect composite resins after accelerated aging. Twelve specimens (15x2mm) were obtained for each tested material. Subsequently, the first measurements for roughness tests and colorimetric spectrophotometry (CIE L*a*b* scale) were performed. Specimens were subject to accelerated aging for 384 hours. New measurements were then performed to evaluate the resulting change. Accelerated aging produced color change and increased surface roughness in all composite resins. Solidex® resin showed color changes above the clinically accepted value (∆E = 4.31±0.22), and roughness values (Ra= 0.088±0,008 µm) statistically lower than that of Artglass® (Ra=0.141±0.026 µm) and Targis® (Ra=0.124±0.02 µm) (p<0.001). All the indirect resins tested showed color change and increased roughness after accelerated aging. Solidex® showed color stability above a quantitative level considered clinically acceptable and lower roughness values compared to the other resins.

KEY WORDS: Material aging, Artificial aging, Colour stability, Surface roughness, Ceromers