Marginal Adaptation of CAD-CAM Fabricated Ceramic Inlays: An in-Vitro Evaluation

Background: Ceramic restorations can be fabricated by using traditional methods like heat-pressing as well as contemporary methods like Computer Aided Designing and Computer Aided Manufacturing (CAD-CAM). Existing evidence regarding the marginal adaptation of CAD-CAM fabricated ceramic inlays is contradictory. Aim: The main objective of the study is to determine the marginal gap widths of CAD-CAM fabricated lithium disilicate ceramic inlays in comparison with heat-pressed ceramic inlays using scanning electron microscopic examination. Materials and methods: Thirty-six intact, caries-free, maxillary first and second premolars were used in the study. Standardized class II disto-occlusal inlay cavities were prepared and were distributed into two groups of 18 specimens, each based on the method of fabrication. The two groups contained CAD-CAM (Group A), and heat-pressed ceramic inlays (Group B). In group A, the prepared inlay cavities were scanned with an intraoral scanner, designed, and milled from IPS e. max CAD blocks. In group B, the ceramic inlays were fabricated by manual impression making and lost wax technique using IPS e. max PRESS ingots and Programat EP 3010 furnace. The fabricated inlays were placed on the prepared cavities of the respective specimens. The scanning electron microscope was used to evaluate the marginal adaptation of specimens at 12 predetermined points for each specimen by a single examiner. The data were subjected to statistical analysis. Results: The mean marginal gap values for CAD-CAM group and heat-pressed were 83.27µm and 87.11µm, respectively. The CAD-CAM ceramic inlays exhibited better marginal adaptation than heat-pressed ceramic inlays with an insignificant difference between the two groups. Conclusion: CAD-CAM method of fabrication did not differ significantly from heat-press method when marginal adaptation property is considered. Moreover, all class II ceramic inlays exhibited minimal gap values.