RESUMO
Marginal gap determines the success rate in all ceramic crown restorations. However, there is insufficient information about marginal fitness of different ceramic systems. The aim of this study was to compare the marginal gap in three different kinds of ceramic restorations namely "In-Ceram", "IPS-e.max Press" and "IPS Empress2". This in-vitro experimental investigation was conducted using a single blind technique. A total of 10 upper incisor teeth were prepared with size reduction 7mm in height, and 5mm diagonally. With a 1mm shoulder finishing line and tapered about 3 degrees. Then 10 ceramic crowns were built on top of each preparation. After cementation they were grinded at buccolingual direction. Finally, marginal gap analysis was conducted using Stereotactic electronic microscope [SEM]. The marginal gap in IPS e.max pres was 29.22 [ +/- 8/59] microm. In-Ceram showed 49.94 [ +/- 9/32] microm and IPS Empress 2 group demonstrated 40.88 [ +/- 5/84] microm. The gap in IPS e.max Press was less than the gap in In-Ceram and IPS Empress 2 in full ceramic restorations