Comparative evaluation of different surfaces fit of digitally fabricated cobalt-chromium copings in two depth of finish lines

Abstract

Background and Aims: Despite the increasing application of intra-oral scanners, the effect of finish line position on gingival margins adaptation is still discussed. The purpose of this clinical study was to evaluate the fitness of cobalt-chromium copings obtained from intraoral scanning in two depth of finish lines. Materials and Methods: Thirty teeth prepared for single premolar metal-ceramic crowns were included. Fifteen teeth had supragingival and fifteen had sub-gingival finish lines. Digital impressions were made using an intraoral scanner (Trios-3shape). Computer-aided design and computer-aided manufacture (CAD/CAM) cobalt-chromium copings were fabricated from the scan files. The copings were evaluated intraorally and after adjustments, the internal and marginal discrepancy were measured using silicone replicas and a stereomicroscopy. Internal and marginal discrepancies were analyzed using the Multivariate test (P0.05). Conclusion: CAD/CAM chrome-cobalt copings fabricated by digital impressions provided acceptable marginal and internal precision. However, the finish line position had no significant effect on the internal and marginal adaptation.

Keywords

• Impression technique
• Marginal adaptation
• Computer-aided design
• Replica technique