Effect of Implant Diameter, Implant Length, and Prosthesis Splinting on Stress Distribution in Posterior Maxillary Implant-Supported Restorations: A Three-Dimensional Finite Element Analysis

Abstract

Purpose:To evaluate and compare the influence of implant diameter, implant length, and prosthetic splinting on stress distribution in posterior maxillary implant-supported restorations using three-dimensional finite element analysis.
Materials and Methods:Ten three-dimensional finite element models of the posterior maxilla with simulated D3 bone quality were developed using SolidWorks software and analysed in ANSYS R17. Five models represented splinted implant-supported restorations, whereas five represented non-splinted restorations. Implants of varying diameters (3.75, 4.2, 5.0, and 6.0 mm) and lengths (10 and 6.25 mm) were evaluated. All models were subjected to nonlinear loading conditions consisting of a 400 N axial load and a 200 N oblique load. Maximum von Mises stresses were analysed in cortical bone, cancellous bone, implant, and prosthetic superstructure.
Results:Cortical bone demonstrated the highest stress concentration in all models, whereas cancellous bone exhibited comparatively lower stress values. Increasing implant diameter progressively reduced cortical bone stress in both splinted and non-splinted restorations. Shortening implant length resulted in only a modest increase in stress concentration. Splinted restorations demonstrated a more uniform distribution of stresses throughout the implant–prosthesis–bone complex than non-splinted restorations. The lowest cortical bone stress was observed in the non-splinted model with a 6-mm-diameter, 6.25-mm-long implant, whereas the highest stress occurred in the splinted model with a 3.75-mm-diameter, 10-mm-long implant.
Conclusion:Implant diameter and prosthetic splinting exerted a greater influence on stress distribution than implant length. Increasing implant diameter significantly reduced cortical bone stress and partially compensated for reduced implant length. Splinted restorations promoted a more favourable biomechanical stress distribution than non-splinted restorations, suggesting that wider implants and splinted prosthetic designs may represent biomechanically advantageous treatment options for posterior maxillary rehabilitation.