Comparing the accuracy of 3D-printed casts versus plaster casts for tooth-supported and implant-supported restorations

ABSTRACT Background: The use of 3D printers in dentistry is expected to increase in the future. However, there is limited information available on the accuracy of dental 3D printers for creating dental and implant models. This study aimed to compare the accuracy of 3D-printed casts and traditional plaster casts for the fabrication of tooth-supported and implant-supported restorations. Materials and Methods: This in vitro study involved a dental model with implant analogs placed at the sites of the right first premolar and molar for an implant-supported bridge and the left first premolar and molar that received preparation for a tooth-supported bridge. Addition silicone impressions were made and poured with dental stone to create 10 plaster casts. The model was scanned using an intraoral scanner, and 20 casts were 3D-printed using digital light processing (DLP) and liquid crystal display (LCD) printers (10 casts for each method). All 30 casts, including the reference model, were scanned using a laboratory scanner, and the obtained Standard Triangle Language files were superimposed in Geomagic software. Data analysis revealed violations of normality and homogeneity of variances. As a result, the Kruskal–Wallis H test, a nonparametric method, was employed to compare root mean square (1 RMS = 100 μm) values across three groups. All statistical analyses were performed using SPSS version 27. RMS values were calculated (P < 0.05). Results: The RMS value was significantly lower in the conventional plaster cast group compared to the LCD group (P = 0.002). However, there was no significant difference between the LCD and DLP groups (P = 0.214) or between the conventional and DLP groups (P = 0.345). The interdental distance in the conventional group was significantly lower than that in the 3D-printed groups (P < 0.05), but there was no significant difference between the two printing methods (P = 0.31). The interimplant distance was lower in the 3D-printed groups compared to the conventional group, and this difference was significant between the DLP and conventional groups (P = 0.02). Conclusion: Although plaster casts demonstrated higher accuracy, 3D-printed casts using additive technology yielded accurate results within the clinically acceptable range (<200 μm).