Effect of a dynamic navigation device on the accuracy of implant placement in the completely edentulous mandible: An in vitro study

Statement of problem A less invasive and more convenient workflow is needed for dynamic navigation-guided implant surgery for the edentulous arch. Purpose The purpose of this in vitro study was to evaluate the accuracy of a novel dynamic navigation device developed for the completely edentulous mandible. Material and methods Two temporary 1-piece mini-implants were placed in the anterior region of a completely edentulous mandibular model for fixation of the navigation device. A total of 40 implants were inserted in 10 completely edentulous mandibular models with the aid of the dynamic navigation device. The accuracy of placement was determined by overlapping the preoperative plan with the postoperative cone beam computed tomography (CBCT) scans. The difference in the accuracy at different implant positions was compared by MANOVA and Bonferroni-corrected ANOVAs. The difference in accuracy between implants #1-20 and #21-40 was assessed for learning progression. Results The deviation of the implants (mean ±standard deviation) was 1.14 ±0.50 mm at the entry point and 1.29 ±0.48 mm at the apex. The mean ±standard deviation angular deviation was 3.02 ±1.32 degrees. No significant difference was seen between the planned and the placed deviation among the 4 implant positions. After repeated placement with this dynamic approach, implant accuracy at the entry (P=.001) and apex (P=.017) improved significantly. Conclusions The navigation device achieved acceptable implant placement accuracy in the edentulous mandible. Deviations between the planned and placed locations were not affected by different implant positions. After repeated operations with this dynamic approach, accuracy at the entry and apex improved significantly.