Effect of fitting procedures on the marginal gap of all-ceramic crowns: an in vitro study

Marginal adaptation is a crucial determinant of dental restoration success, directly influencing longevity and clinical outcomes. This study investigated the impact of fitting procedures on the marginal adaptation of CAD/CAM-fabricated all-ceramic crowns. Eight extracted human molars were prepared for crown fabrication using standardized techniques. An impression was carried out for each specimen and poured with type IV dental stone, followed by the CAD/CAM-based design and fabrication of the crowns. Marginal gaps were measured at eight designated points on each specimen using a Hirox Digital Microscope, both before and after fitting procedures. Findings revealed a significant reduction in marginal gaps post-adjustment, with values ranging from 270.55 μm to 9.64 μm before the fitting procedure and 124.4 μm to 3.81 μm after fitting procedures. These results emphasize the efficacy and importance of fitting procedures in enhancing marginal fit, reducing gaps to clinically acceptable levels, and minimizing potential complications such as microleakage and secondary caries. The study highlights the critical role of fitting procedures in optimizing the marginal fit of CAD/CAM crowns, thereby improving their clinical performance and longevity.