SEM study of surface characteristics and marginal adaptation of anterior resin restorations after 3-4 years.

SEM replica technique was used to study surface characteristics and marginal adaptation of 278 anterior resin fillings 3-4 yr old. The fillings showed degradation of surfaces and margins with eroded areas and exposed macro- and microfiller particles. Cohesive failures were seen as chip fractures and marginal fractures parallel to the cavity margins. Microfiller resin fillings showed less rough surface characteristics than the conventional and hybrid composite resins in spite of a higher frequency of fillings with surface degradation. The microfiller resin fillings activated by visible light, in particular, showed relatively smooth surface characteristics with less surface degradation and less porosity. About 50% of the conventional and hybrid composite fillings showed marginal defects. The two chemically cured microfiller resin fillings showed marginal defects in 66% or 88%, whereas for the visible light cured microfiller resin fillings defects were observed in 44%.