Accuracy of Complete Digital Workflow for Fabrication of Implant-Supported FDPs: In-vitro Study in the Anterior Maxilla

Abstract

Objective: To assess the accuracy of fit of implant-supported, (Polymethylmethacrylate) PMMA screw-retained prostheses fabricated using complete digital workflow. Materials and Methods: A partially edentulous maxillary 3D printed cast -Kennedy class IV- with two bone-level internal connection implants (Straumann Bone Level RC) placed at lateral incisors position (#7, #10) was used as the reference cast. A total of 50 (N=50) scans of the cast were acquired using the TRIOS scanner (TRIOS 4, 3Shape, Copenhagen, Denmark) in a controlled environment. The digital scans were exported in the Standard Tessellation Language (STL) format. The STL files were imported into CAD software (Exocad, DentalCAD version 3). Utilizing the software, a reference PMMA 4-unit implant-supported prototype prosthesis at the implant level (RC; Straumann®, Switzerland) was created. The assessment of prosthesis fit was carried out using the screw resistance test and radiographic analysis. Results: The results of the screw resistance test revealed that 98% (N=49) of the PMMA implant-supported prostheses exhibited a fit that was considered clinically acceptable. However, when assessing the fit radiographically, it was found that all 50 prototypes (100%) achieved a clinically acceptable fit. Conclusion: Within the limitations of this in vitro study, the accuracy of fit of implant-supported, PMMA screw-retained prosthesis fabricated using complete digital workflow was found to be clinically acceptable in the scenario of partially edentulous anterior maxilla.