Marginal fit of porcelain and indirect composite laminate veneers under in vitro conditions

The purpose of the present study was to compare the marginal adaptation of indirect composite and porcelain veneers in vitro using transmitted-light microscopy. A preparation with a marginal chamber finish for a veneer was performed on 10 extracted molars after which 5 composite and 5 porcelain veneers were made and fitted using self- and light-cured microfill composite resin. Three longitudinal and 3 horizontal sections were cut in each preparation with the light microscope. Although the absolute marginal discrepancy at the cervical location had the highest statistical significance in the composite veneer group, the composite and porcelain veneers, in general, demonstrated a similar absolute marginal discrepancy and thickness of luting agent with average values from 50 microns to 195 microns for the two parameters. A considerable amount of excess of luting agent was furthermore observed in both groups of veneers, being most pronounced in the composite veneers.