Cortical stress around all-on-six implants: A finite element analysis

Abstract

Rehabilitation of the atrophic edentulous maxilla remains biomechanically challenging, particularly regarding optimal posterior implant configuration. Therefore, it is of interest to compare the two All-on-six configurations using 2D and 3D models reconstructed from CBCT data: tilted posterior implants with distal cantilever (M6T) and posterior short implants without cantilever (M6S). Under full-mouth, anterior, lateral and unilateral posterior loading, M6S consistently produced lower stress and displacement than M6T. Maximum cortical bone stress during full-mouth loading was substantially lower with M6S than M6T (29.72 vs. 161.12 MPa), with similarly reduced implant and framework stresses. Thus, posterior short implants provided more favorable biomechanical load distribution and structural stability, supporting their consideration as an alternative to tilted implants with distal cantilever in atrophic maxillary rehabilitation.