Accuracy of 3D-Printed Master Cast Workflow Using a Digital Light Processing Printer

Applied Sciences, vol. 12, pp. 2619

Abstract

This in vitro study was designed to investigate whether conventionally produced casts and printed casts for prosthodontic purposes show comparable full-arch accuracy; a ceramic reference cast with inlay and crown preparations was fabricated. Ten gypsum casts were fabricated from conventional silicone elastomeric impressions. Ten digital impressions [IOS] of the reference cast were obtained by an intraoral scanner to fabricate 3D-printed resin casts. The ceramic reference cast, the gypsum, and the printed casts were digitized by an industrial structured light scanner (ILS) and provided as stl files. To evaluate absolute mean trueness values, the digitized gypsum casts [CON], digitized printed casts [PRINT], and [IOS] were superimposed with the digitized ceramic reference cast [REF]. Additionally, each [IOS] scan was compared with its corresponding [PRINT]. The precision was calculated for [CON], [IOS], and [PRINT]. The Mann–Whitney U test for independent samples and the Wilcoxon test for connected samples were performed (p ≤ 0.05). As absolute mean deviation trueness values were obtained: 69 ± 24 µm for [REF]-[CON], 33 ± 4 µm for [REF]-[PRINT], and 19 ± 3 µm for [REF]-[IOS]. The superimposition [IOS]-[PRINT] revealed 38 ± 6 µm. The precision was 74 ± 22 µm for [CON], 32 ± 10 µm for [PRINT], and 15 ± 4 µm for [IOS]. With respect to the workflow, the trueness values of [REF]-[CON] and [REF]-[PRINT] differed significantly. Within the digital workflow, [REF]-[PRINT], [REF]-[IOS], and [IOS]-[PRINT], all values differed significantly. Within the limitations of the study, digital impression and printed cast fabrication were more accurate and reproducible than the conventional workflow.

Authors 5

1. Saskia Berndt corresponding Aachen Department of Prosthodontics and Biomaterials

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department of Prosthodontics and Biomaterials, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany

2. Hannah Herstell Aachen Department of Prosthodontics and Biomaterials

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department of Prosthodontics and Biomaterials, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany

3. Stefan Raith Aachen Department of Oral and Maxillofacial Surgery

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department of Oral and Maxillofacial Surgery, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany

4. Christina Kühne Aachen Department of Prosthodontics and Biomaterials

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department of Prosthodontics and Biomaterials, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany

5. Sven Reich Aachen Department of Prosthodontics and Biomaterials

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department of Prosthodontics and Biomaterials, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany