CLINICAL AND BIOMECHANICAL COMPARISON OF ALL-ON-4 AND ALL-ON-6 PROTOCOLS FOR COMPLETE EDENTULISM

Abstract

Full-arch implant rehabilitation has become a predictable option for the management of complete edentulism. Among fixed protocols, All-on-4 and All-on-6 are the two most frequently compared concepts. The former was developed to maximize the use of available anterior bone, reduce the need for grafting, and enable immediate loading with a limited number of implants. The latter seeks to increase the anteroposterior spread, improve load distribution, and provide greater biomechanical reserve. This extended abstract critically compares both protocols with regard to implant and prosthesis survival, marginal bone behavior, biological and technical complications, biomechanical rationale, and practical treatment planning. The available evidence indicates that both concepts can provide reliable long-term outcomes when primary stability, prosthetic design, occlusal control, and maintenance are adequate. However, the putative advantages of six implants are demonstrated more consistently in biomechanical and engineering studies than in direct clinical comparisons. Therefore, protocol selection should not be ideological; it should be individualized according to anatomy, bone density, occlusal demand, cantilever control, prosthetic material, maintenance burden, and patient expectations.