Three-dimensional finite element analysis of stress distribution on different complex macro designs in commercially available implants: An in-vitro study

Objective: This study aimed to investigate the effects of different commercially available complex implant macro designs on stress distributions using Finite element analysis. The experiment is done under varying simulated bone conditions to provide reference for clinical application.

Materials and methods: The study employed the Finite Element Analysis (FEA) method to compare four commercially available complex implant macro designs on a Computer-Aided Design (CAD) model of a maxillary bone segment. The three-dimensional geometrical model of the implants was reconstructed from computed tomography (CT)-slices in Digital Imaging and Communications in Medicine (DICOM) format and contact condition between the implant and the bone was considered as 'Bonded', implying perfect osseointegration. All materials used in the models were assumed to be isotropic, homogeneous, and linearly elastic. The Finite element simulations employed load of 400 N under both axial and non-axial conditions Stresses were analysed under different bone conditions.

Results: Average values of von Mises stresses were used for comparing stress levels between implant designs. There was a definite increase in the equivalent stress values from higher density(D1)to lower density (D4) bone conditions for all implants. The percentage of increase ranged from 23.63 to 49.39 on axial loading and 20.39 to 57.19 when subjected to non-axial loading. The equivalent stress values resulted from non-axial loading were 1.78-2.94 times higher than that of axial loading for all implants under all bone densities. Among the complex designs Equinox Myriad Plus implant exhibited the least stress under axial loading (12.749-19.046 MPa) and (37.462-49.217 MPa) for non-axial loading. The stress on the crestal module was higher (1.49-2.99 times) than the overall stress on the implant regardless of the loading direction or bone conditions.

Conclusions: Data from the present study shows Equinox Myriad Plus implant generating the least equivalent stress and this can be taken as indicator in the biomechanical performance of the design.