How Accurate Is Oral Implant Installation Using Surgical Guides Printed from a Degradable and Steam-Sterilized Biopolymer?

Abstract

3D printed surgical guides are used for prosthetically-driven oral implant placement. When manufacturing these guides, information regarding suitable printing techniques and materials as well as the necessity for additional, non-printed stock parts such as metal sleeves is scarce. The aim of the investigation was to determine the accuracy of a surgical workflow for oral implant placement using guides manufactured by means of fused deposition modeling (FDM) from a biodegradable and sterilizable biopolymer filament. Furthermore, the potential benefit of metal sleeve inserts should be assessed. A surgical guide was designed for the installation of two implants in the region of the second premolar (SP) and second molar (SM) in a mandibular typodont model. For two additive manufacturing techniques (stereolithography [SLA]: reference group, FDM: observational group) n = 10 surgical guides, with (S) and without (NS) metal sleeves, were used. This resulted in 4 groups of 10 samples each (SLA-S/NS, FDM-S/NS). Target and real implant positions were superimposed and compared using a dedicated software. Sagittal, transversal, and vertical discrepancies at the level of the implant shoulder, apex and regarding the main axis were determined. MANOVA with posthoc Tukey tests were performed for statistical analyses. Placed implants showed sagittal and transversal discrepancies of <1 mm, vertical discrepancies of <0.6 mm, and axial deviations of ≤3°. In the vertical dimension, no differences between the four groups were measured (p ≤ 0.054). In the sagittal dimension, SLA groups showed decreased deviations in the implant shoulder region compared to FDM (p ≤ 0.033), whereas no differences in the transversal dimension between the groups were measured (p ≤ 0.054). The use of metal sleeves did not affect axial, vertical, and sagittal accuracy, but resulted in increased transversal deviations (p = 0.001). Regarding accuracy, biopolymer-based surgical guides manufactured by means of FDM present similar accuracy than SLA. Cytotoxicity tests are necessary to confirm their biocompatibility in the oral environment.

Does the macro design of an implant affect the accuracy of template-guided implantation? A prospective clinical study

“…However, another study using templates from different printers did not demonstrate any significant differences [ 38 ]. In a study on the influence of two different printing materials for templates, no significant differences were found [ 13 ]. An in vitro study by Henprasert et al showed that the fabrication of the template in an additive or subtractive process had no influence on the implant position [ 12 ].…”

Accuracy of Computer-Assisted Dynamic Navigation as a Function of Different Intraoral Reference Systems: An In Vitro Study

“…Various studies regarding the accuracy of static navigation have identified influencing factors including intraoral positioning and fixation of templates [ 14 ]. The manufacturing process for the drill template can also impact the accuracy of implant placement, as can the materials used [ 15 , 16 , 17 ]. Several studies have reported the influence of different drill sleeves on accuracy [ 18 , 19 , 20 ].…”

Digital Implant Planning: A Brief Narrative Review

“…Three types of computer-generated surgical guides are currently available: supported by teeth, mucosa and bone. Tooth-supported guides are used in cases of partial edentulism [12].…”