Comparing accuracy of surgical guides fabricated by additive method (3D printing) versus subtractive method (milling by CAD/CAM) for prosthetically driven implant placement : “An in-vitro atudy” /

Abstract

Prosthetically driven implant surgery offers a higher degree of precision when placing dental implants, resulting in more predictable prosthetic outcomes compared to non guided surgeries. This study aimed to assess the precision of surgical guides produced through CAD/CAM milling and SLA 3D printing methods in achieving the desired implant positions for prosthetically driven implant placement. To conduct the study, twenty-four epoxy resin models, each featuring a missing mandibular first molar, were prepared. Implant placement was virtually planned using 3D implant planning software. Subsequently, twelve surgical guides were created by milling PMMA blocks, while another set of twelve guides was produced using a SLA 3D printer. The fit and stability of the surgical guides were meticulously assessed prior to the drilling procedure. A total of 24 dental implants (5.5×11 mm) were placed using tooth-supported surgical guides and a fully guided implant surgical kit. The placement of dental implants was digitally scanned utilizing scan bodies and an extra-oral scanner. Specialized 3D analysis software was employed to evaluate the implant positions and the accuracy of the surgical guides. This evaluation fabricated a comparison between the planned implant positions and the actual placements, with measurements of deviations recorded at the point of entry, apical position, and angular deviations. The root mean square (RMS) of errors was calculated for both sets of surgical guides. Statistical analysis was performed using the Mann-Whitney U test (P ≤0.05). Results of the study indicated that SLA 3D printed surgical guides exhibited higher accuracy when compared to CAD/CAM milled guides. Statistically significant differences were observed between the two in terms of angular deviation (P<0.001), while there was no significance difference in terms of point of entry (P=0.689), and apical position (P=0.471). Overall, SLA 3D printed surgical guides demonstrated lower deviations.