Accuracy of Conventional and 3D-Printed Casts for Partial Fixed Prostheses

Purpose: To evaluate and compare the accuracy of conventional and 3D-printed casts using five different 3D printers. Materials and Methods: In the control group (CG group, n = 5), five conventional impressions using light- and heavy- body polyvinyl siloxane were obtained from the master model, resulting in five stone models. In the test groups, five different scans were performed by a well-trained and experienced clinician using a TRIOS intraoral scanner. All data were exported in STL file format, processed, and sent to five 3D printers. Five casts were manufactured in each printer group: SG (CARES P20, Straumann); FG (Form 2, Formlabs); WG (Duplicator 7, Wanhao); ZG (Zenith D, Zenith); and MG (Moonray S100, Moonray). Measurements of the accuracy (trueness and precision) of the casts obtained from conventional elastomeric impressions and 3D-printing methods were accomplished using a 3D analysis software (Geomagic Control). Results: The FG group showed the lowest values for trueness (indicating a value closer to real dimensions), which were similar to the SG group only (P >.05). MG, WG, and ZG groups presented higher values and were similar compared to each other. Data on precision demonstrated that all 3D-printed groups showed lower values for precision (smaller deviation) when compared to the CG. Conclusions: The trueness depends on the chosen 3D printer. All of the tested 3D printers were more precise than cast models obtained from conventional elastomeric impressions.