COMPARISON OF MARGINAL FIT IN COPINGS MANUFACTURED BY CONVENTIONAL AND CAD-CAM TECHNIQUES

Introduction The marginal accuracy of prosthetic copings is a determining factor in the longevity of fixed prostheses. Conventional casting techniques and digital CAD-CAM technologies offer different levels of precision, making it essential to compare their outcomes in order to optimize clinical protocols. Objectives To compare in vitro the marginal fit of metal copings manufactured by conventional casting and CAD-CAM systems. Materials and Methods A total of 40 copings (20 per technique) were fabricated on plaster models with standardized preparations. Conventional copings were produced using the lost-wax casting technique, whereas digital copings were made through scanning, CAD design, and CAM milling. Marginal discrepancy was evaluated using scanning electron microscopy (SEM). Results CAD-CAM copings showed an average marginal fit of 50±10 µm, whereas conventional copings recorded 85±15 µm. The difference was statistically significant (p<0.05). Conclusions The CAD-CAM technique demonstrated superior marginal fit compared to the conventional technique, suggesting its potential to improve prosthetic adaptation and reduce the risk of bacterial leakage.