"Accuracy of 3D printed implant surgical guides with the manufacturer workflow of four different printers. A comparative in vitro study."

ABSTRACT

OBJECTIVES: The aim of this study was to assess the accuracy of surgical guides printed using four different manufacturer workflows. METHODS: Forty-eight surgical guides (BlueSky Plan, BlueSky Bio) were produced using four different printers, with strict adherence to each manufacturer's instructions. The printers used were three DLP printers (SolFlex170 (VC), Nextdent5100 (ND), D30+Rapidshape (RS)) and one SLA printer (Formlabs3B+ (FL)). The study evaluated the trueness and precision of the overall surface, the region of interest (RoI) (occlusal and guide zone), the repeatability in several batches, and the guide hole's diameter and xyz axes. The printed guides were digitized and compared with the CAD design control specimen (Control X, Geomagic). Descriptive statistics and Kruskal-Wallis tests with post-hoc Mann-Whitney tests were performed (α=0.05). RESULTS: Statistical analysis revealed differences in trueness and precision were found between groups in the overall zone and RoI (p=0.00). The ND group demonstrated the highest repeatability. Only the RS group exhibited a comparable guide hole diameter to the master specimen (5.27±2.12 mm; p=0.104). No statistical differences were observed between groups in the x and z axes. However, in the y-axis, the VC group displayed statistically significant differences (p=0.01). CONCLUSIONS: The results showed that the DLP groups had better overall accuracy, while the SLA group had the best results in the RoI. The manufacturer's workflows demonstrated a high reproducibility between batches in the RoI. The RS group had values most similar values to the guide hole diameter of the master specimen, with minimal deviations in guide hole orientation. CLINICAL SIGNIFICANCE: Implant position is a crucial factor in the long-term success, and it can be affected by the accuracy of the 3D printed surgical guide. Therefore, it is critical to analyze the final dimensions and the direction of the guide hole using available printing technologies.