[Scanning electron microscopy of marginal fitting of composite resin fillings]

The aim of the present in vitro study was to evaluate the marginal gap formation of composite restorations. Class V. cavities were prepared on the buccal surfaces of 30 human teeth and restored with Prime & Bond 2.1 (Spectrum TPH and Syntac Single-Component) Tetric. The specimens were examined by scanning electron microscope (SEM). By measurement of marginal gap dimensions this study aimed at comparing the marginal fitting and bonding potentials of current generation composite resins and adhesive systems. The data were analyzed by a two-sample t-test. No significant differences were detected (p < 0.001) between the two groups. The specimens showed very narrow gaps of 0-5 microns thickness and 60% of the composite fillings presented gap-free attachment to enamel. These results may have significant implications related to clinical longevity of composite restorations.