The rise in the number of dental implants has resulted in a proportional increase in reported complications. These may range from restorative issues caused by inaccurate placement to injury of nearby anatomical structures such as nerves or adjacent teeth. Most of these complications can be prevented by placing implants in an optimal position with precision. Hence, this in vitro pilot study aimed to assess the influence of freehand (FH) and fully guided (FG) surgical techniques on the precision of implant placement near critical structures like the inferior alveolar nerve (IAN). Cone-beam computed tomography (CBCT) and intraoral scans from six individuals with prior mandibular implants were utilized. Ideal implant positioning was digitally planned, and FG surgical guides were produced for each case. Three-dimensional resin models were printed, and implants were inserted using both FH and FG methods on corresponding models. The study measured angular deviation and the distance between the implant apex and the IAN. FH placement showed mean deviations of 1.10 mm coronally, 1.88 mm apically, and up to 6.3° angular deviation, whereas FG surgery demonstrated deviations of 0.35 mm coronally, 0.43 mm apically, and 0.78° angularly. The furthest distance between the implant apex and the IAN was 2.55 mm for FH and 0.63 mm for FG. Within its experimental limitations, this bench-top study indicated both FH and FG techniques can achieve acceptable surgical accuracy for implant placement near the IAN if a 3 mm safety margin is maintained. However, FG surgery—particularly using the R2 Gate® system—showed superior control and lower angular error.
