Influence of 3D Printing Technology, Resin Type, and Occlusal Design on the Accuracy of Surgical Guides
Abstract
Aims: The present study aimed to assess the accuracy of surgical guides fabricated using two different 3D printers, two resins, and different occlusal designs (OS: original shape; GS: groove sealing). Materials and Methods: Forty surgical guides were printed on a digital light processing (DLP) printer and a Liquid Crystal Display (LCD) printer, with two resin types (SG guide and V-guide) and two occlusal designs. The region where the implant was planned was digitally removed from the cast, allowing passive positioning of the implant through the guide. A scan body was inserted in the implant, and the cast was scanned with an intraoral scanner. The planned implant was compared with the actual implant position. Six measurements representing the accuracy of implant placement: (depth, angular, global apical, horizontal apical, global coronal, and horizontal coronal) deviations. Descriptive statistics and a multivariate analysis of variance (MANOVA) were conducted. Results: The DLP printer and GS group exhibited lower mean deviation and standard deviation across all measured parameters. Printer type had a statistically significant multivariate effect (Wilks’ Lambda = 0.015, p< 0.001, Partial η² = 0.985). The resin type had no multivariate effect on the combined dependent variables, as indicated by Wilks’ Λ = 0.727, p = 0.161. Occlusal shape showed a significant multivariate effect (Wilks’ Lambda = 0.015, p<0.001). The univariate tests revealed that printer type and the shape of the occlusal surface had a statistically significant effect on all six deviation parameters (p < 0.001 for all); however, resin type had a significant effect only on horizontal coronal deviation (p = 0.018). Conclusion: The DLP printer was more accurate than the LCD printer. Also, the accuracy of a surgical guide can be improved by sealing the occlusal surface grooves directly before fabricating the guide. The accuracy of both SG and V-guide resins was the same