Effect of the degree of polymerization on the intrinsic discoloration of light activated resin composite restorations

ABSTRACT

This study was carried out to investigate the effect oft he degree of polymerization on the intrinsic discoloration of light activated resin composite restorations. Three different commercially available resin composites were used in this study. Each group was subdivided into three sub groups, according to time of curing. Half of the specimens in each sub group, where stored in dry condition while the other half was stored in coffee. Color was assessed by the spectrophotometer and degree of polymerization was measured by FTIR. The collected data were statistically analyzed using two way analysis of variance [ANOVA]. Reverse relationship was found between the intrinsic discoloration and the degree of polymerization. The curing time should not be less than 40 sec. to ensure better color stability of different resin composites