The effects of short bevels and silanization on marginal adaptation of computer-machined mesio-occlusodistal inlays

Mesio-occlusodistal cavities were prepared in extracted human molars and restored using computer-m,achined ceramic inlays. In five groups of six restorations each, short bevels (0.5-mm) were placed either at the cervical and lateral margins or combinations of lateral, cervical, and occlusal enamel margins. An unbeveled group served as a control. In addition, the effect of inlay silanization was evaluated in two of the groups. Marginal adaptation of the inlays was assessed in the scanning electron microscope before and after a combined chemical, abrasive, thermal, and chewing load cycle test. Marginal adaptation at the enamel-composite resin interface did not differ significantly between the groups before and after the test. Marginal adaptation of the silanized ceramic interface was significantly better than that of the unsilanized ceramic (99.73% versus 76.33%). There was no correlation between the marginal width of the composite resin luting material and micromorphologic marginal quality. Dye penetration tests revealed that the cervical enamel margins were perfectly sealed; however, the cervical dentinal margins leaked in all specimens.