Abstract: Objective：To evaluate the applicability, accuracy and clinical outcome of the computer assisted design and computer assisted manufacture (CAD & CAM) tooth-supported implant surgical guide in the mandibular free-end partially edentulous patients with insufficient vertical bone height. Methods: According to the inclusion criteria, 3 patients (2 women, and 1 man) with the mean age of 45 years (from 44 to 46 years) with 10 implant sites were involved in this study. With the help of computer-assisted-design software to plan and simulate the surgical strategies, the implant surgical guides were fabricated via the rapid prototyping technique, then the guided implant placement was implemented, finally the post-surgical evaluations were accomplished by the clinical and radiographic examinations. Results: Ten implants were placed in 3 mandibles via the surgical guides, and the implant supported non-split restorations were in place. All the implant restorations revealed good clinical function until the last review. No inferior alveolar nerve injury was detected by the clinical neurosensory test. The immediate post surgical CBCT was performed to confirm a safe distance of 1.5 to 3.0 mm between the implant apical and the nerve canal. The deviations between the planed and the actually placed implant were: coronal deviation (0.84±0.30) mm (0.31-1.24 mm); apical deviation (1.42±0.52) mm (0.52-2.36 mm); angular deviation 7.65°±1.84° (4.43°-9.81°). Conclusion: In case of distal free-end partially edentulous with insufficient vertical bone height in the posterior mandibular region, computer assisted surgical design and guided surgery can offer a treatment option with minimal invasiveness and a shorter treatment period, and avoid the complicated bone augmentation procedure and the high risk of nerve transposition. This technique is clinically and technically feasible, but the cases using this technique should be strictly selected according to the indication.

Key words: Computer-aided design, Dental prosthesis, implant-supported, Bone resorption, Jaw, edentulous, Mandible