Abstract: Objective: To investigate the clinical results of all-on-4 for edentulous patients caused by severe periodontitis. Methods: Twenty-five patients were performed with all-on-4 at immediate implantation and immediate loading. Plaque index, sulcular bleeding index, and probing depth were measured at 3, 6, and 12 months after permanent restoration. The satisfied degree, masticatory efficiency, and success rate were calculated. Results: Success rate and masticatory efficiency were 99% and 69.97%, respectively at 12 months after permanent restoration. There was no significant difference in plaque index at 3, 6, and 12 months after permanent restoration. Sulcular bleeding index at 12 month was the highest (P＜0.05). Probing depth after 6 months was higher than that after 3 months (P＜0.05). The satisfied degrees for stability and articulation of denture were both 100%, for aesthetics was 92%, for masticatory efficiency was 96%, and for comfortability was 88%. Conclusion: All-on-4 showed good performance in the success rate and masticatory efficiency in short-term.

Key words: Edentulous, Immediate implantation, Immediate loading, All-on-4