Computer-Guided Flapless Immediate Function Dental Implants for Full-Arch Rehabilitations Using the All-on-4 Concept: A 12-Year Clinical and 10-Year Radiographic Retrospective Study

Background/Objectives: Implant-supported rehabilitations using the All-on-4 concept represent a viable treatment option for completely edentulous patients. The guided surgery software allows for the performance of a flapless computer-guided surgery with similar results to those achieved through a flap surgery. This study aimed to evaluate the long-term outcomes of complete edentulous implant-supported rehabilitations using an All-on-4 arrangement, following a computer-guided protocol. Methods: A total of 111 patients (68 females, 43 males) with an average age of 60.9 years ± 9.67 years were treated. The primary outcome measures were implant and prosthetic survival. Secondary outcome measures were marginal bone loss (MBL) and the incidence of mechanical and biological complications. Results: Thirty-nine patients were lost to follow-up. Thirty-seven implants and five prostheses failed, rendering a 92.5% implant cumulative survival rate and a 96.2% prosthetic survival rate at 12 years. The average MBL per implant was 1.19 ± 1.16 mm, with 1.26 ± 1.33 mm for axial implants and 1.12 ± 0.95 mm for tilted implants at 10 years. The incidence rate of mechanical complications at the patient level was 90.1% for provisional prostheses and 55.9% for definitive prostheses. The rate of biological complications was 14.3% at the implant level. Conclusions: Full-arch rehabilitations following an All-on-4 implant arrangement and assisted by a computer-guided protocol may be a viable alternative for patients with edentulism/hopeless teeth in the long term.