Immediate rehabilitation of the edentulous and potential edentulous jaws with implant-supported full-arch prostheses: a retrospective analysis of 225 cases

Abstract

Objective: To evaluate the outcomes of immediate rehabilitation of the edentulous and potential edentulous jaws with implant-supported full-arch prostheses and analyse the risk factors of the complications. Methods: This retrospective study included 273 patients treated with immediate rehabilitation of the edentulous and potential edentulous jaws with implant-supported full-arch prostheses from April 2008 to December 2018 in Department of Implantology, Peking University School and Hospital of Stomatology. The patients' sex, age, place of residence, jaw position, opposing dentition, number of implants, diameter and length of implants, abutment height and abutment angle were recorded. The survival rate of implants and marginal bone loss were calculated and analyzed. Cox proportional hazards ratio model was adopted to analyze the potential risk factors of prosthetic complications. Results: A total of 225 patients (288 jaws) and 1 260 implants were included, with 126 males and 99 females, aged (57.3±11.0) years, with a following time of (5.04±3.08) years. The 1-year cumulative survival rate of implants was 98.0% (1 235/1 260). Forty-eight implants were lost during the follow-up, with 39 implants in the maxillae and 9 implants in the mandible. The risk of implant failure of the maxillae ［7.2% （39/541）］ is significantly higher than that of the mandible ［1.3% （9/719）］ (P<0.01). Average marginal bone loss at 1 and 5 years was (0.7±0.2） mm and （1.1±0.3） mm. One hundred and twenty patients experienced prosthetic complications including screw/abutment loosening (44 cases), screw/abutment fracture (2 cases) and artificial tooth/denture base fracture (99 cases). The possibility of immediate prosthesis fracture within 6-8 months was high but declined over the following years with the final prosthesis delivered. Cox regression analysis showed that the use of 17° abutments in the anterior region was significantly related to the prosthetic complications （hazard ratio=1.797, P=0.002）. Conclusions: Immediate rehabilitation of the edentulous jaws with implant-supported full-arch prostheses can be a predictable technique. The immediate prosthetic mechanical complication prevalence was high. The use of 17° abutments in the anterior region may increase the risk of screw/abutment loosening. It is necessary to review in time.