Accuracy of Navigation-Guided Dental Implant Placement with Screw Versus Hand Template Fixation in the Edentulous Mandible

Preoperative planning of the implant position as part of a coordinated prosthetic and surgical concept is becoming increasingly important regarding function and esthetics. The aim of this study was to investigate the transmission accuracy of template fixation during surgery in edentulous arches with hand fixation in comparison to intermediary screw fixation.Preoperatively, 10 implant positions were planned using computed tomography (CT) with the system med3D for implant placement in four mandible models of the Goettingen study model, using a prosthetic diagnostic template. A total of 40 implant insertions were created. For every 20 insertions, the template was temporarily fixed with three screws and compared with the insertion using a hand-fixed template. The precision of the transmission was evaluated with and without screw fixation by re-evaluating the preimplant planning with additional CT scanning of the respective models.Compared with the hand-fixed procedure (HFG) in the model situation, there were no significant differences between the deviations of planned and final implant position in the screw-fixed group (FG). According to the study results, the fixed procedure leads to less depth deviation and lateral error of the implant base in relation to the HFG. Within both groups, there were significant differences between the radial deviation tendencies from the implant base to the implant apex (P = .033 for FG and P = .001 for HFG).The use of CT-based implant planning succeeds in fixed and hand-fixed surgical procedures with high precision in the atrophic, edentulous mandible model. According to the results of this study, in cases demanding high depth precision, screw-fixation of the template can be helpful.