Accuracy of computer-aided design trial restorations fabricated with different digital workflows

• Published in: The Journal of prosthetic dentistry 2024-09, Vol.132 (3), p.578-585
• Main Authors: Taha, Doaa, Allam, Sara, Morsi, Tarek
• Format: Article
• Language: English
• Subjects: Computer-Aided Design; Dental Prosthesis Design - methods; Dental Restoration, Permanent - methods; Esthetics, Dental; Humans; Imaging, Three-Dimensional - methods; In Vitro Techniques; Smiling; Software; Workflow
• ISSN: 0022-3913; 1097-6841; 1097-6841
• DOI: 10.1016/j.prosdent.2023.09.034

Trial restorations are a versatile tool for visualizing the esthetic treatment plan and should be an accurate replica of the planned smile design. The accuracy of conventionally fabricated trial restorations has been investigated; however, studies on the accuracy of different digital workflows for trial restoration fabrication are lacking. The purpose of this in vitro study was to evaluate the accuracy of computer-aided design (CAD) trial restorations fabricated with different digital workflows. A patient in need of additive esthetic treatment was examined, and intraoral and extraoral photographs and intraoral digital scans were made, followed by 3D digital smile design using the exocad software program. The reference virtual design was converted into trial restorations (N=40) by using different digital workflows: subtractive manufacturing, additive manufacturing, additive manufacturing of 3D designed index, and silicone index on an additively manufactured cast. Fabricated trial restorations of all groups were scanned with a desktop scanner, providing a standard tessellation language (STL) file serving as the test data for each trial restoration. All the STL files of the test and reference data were imported into a reverse engineering software program to evaluate the 3D trueness of each workflow. Also, analog and digital 2D linear measurements (maxillary left central incisor height, maxillary left central incisor width, and intercanine width) were made to assess any dimensional alterations between the fabricated trial restorations and the reference digital smile design. A 1-way analysis of variance (ANOVA) was used to analyze the data followed by the Tukey post hoc test (α=.05). For 3D trueness measurements, root mean square (RMS) values representing the deviations between the fabricated trial restorations and the reference digital smile design varied significantly among the different groups (P