Comparative Evaluation Of The Marginal Fit Of Emax Crown Fabricated With Cad Cam Technology Using Digital Impression And Conventional Impression: An In Vivo Study

Abstract

Aim: compare the marginal fit of Emax crown fabricated from impressions acquired by direct intraoral digital scan and conventional impression with lab scan.

Materials and methods: In each of 20 participants, EMAX crowns for maxillary anterior teeth were fabricated. Digital workflow was applied for the fabrication of EMAX crowns with 3 shape trios system. The conventional workflow included a single step PVS impression, lab scanning, and the casting of a metal coping. The marginal discrepancy on mesial and distal areas between the crown and the abutment teeth was registered using the replica technique with polyvinyl siloxane and radiographically by Periapical radiograph with parallel technique. The dimensions of the marginal discrepancy were assessed using a stereomicroscope.

Results: In digital workflow group, buccally, mesial discrepancy was 98.58µm and distal was 102.24µm. lingually  mesial discrepancy was 99.17µm and distal was 102.82µm.

              In Conventional Workflow group buccally,  mesial discrepancy was 104.83µm and distal was 104.98µm. lingually  mesial discrepancy was 105.21µm and distal was 105.75µm.

              The difference between the digital and the conventional workflow was statistically insignificant (P>0.05).

Conclusion:

1. There is no statistical difference in a marginal discrepancy of EMAX crowns fabricated using digital impression using an intraoral scanner and with conventional impression using lab scan.
2. The mean marginal discrepancy in both groups was within the limits of clinical acceptability.

Clinical significance: An essential factor for success of any restorative workflow is the marginal and internal fit of the resulting prosthesis. In the new era of digitalization, use of an intraoral scanning is increasing, hence there is a growing need to explore the accuracy, durability of restorations fabricated using intraoral scanner.