A Three-dimensional Finite Element Analysis of Effect of Abutment Materials on Stress Distribution around Peri-Implant Bone in Immediate and Delayed Loading Conditions

Abstract

Introduction: Osseointegration is important for successful dental implant treatments. Abutment materials affect the load transfer to the implant and surrounding bone thus determining the long term implant survival. Aim: Stress analysis around peri-implant hard tissue with different abutment materials and their comparative evaluation in immediate and delayed loading conditions using finite element analysis. Material and Methods: An in-vitro experimental study was carried out on a root form titanium grade IV Implant, assembled with an abutment Ø4.0-0.5GH and this test model was Threedimensional (3D) scanned, reconstructed on Computer-aided design software CREO. Six abutment groups: Group 1- Zirconia with DL (Delayed Loading), Group 2- Polyether Ether Ketone (PEEK) with DL, Group 3- Titanium grade Extra Low Interstitial (ELI) with DL, Group 4- Zirconia with IL (Immediate Loading), Group 5- PEEK with IL, Group 6- Titanium Grade ELI with IL, were loaded from vertical, horizontal and oblique direction. Von Mises and principal stress analysis was done on the implant and the peri-implant bone using the finite element method and the statistical analysis was done. Results: For delayed loading group, highest stresses were generated in group 1 (462.88 MPa), followed by group 3 (413.72 MPa) and least in group 2 (319.38 MPa). For immediate loading, highest to lowest stresses were in group 4 (694.32 MPa), Group 6 (620.58 MPa) and group 5 (479.07 MPa). The principal stress analysis showed significant difference between all groups in cancellous bone and cortical bone except between titanium and customised zirconia abutment in cortical bone in delayed loading (p=0.0846) and in immediate loading (p=0.1125). Conclusion: Change in abutment materials significantly affects the stress generated in and around the implant thus more studies must be carried out to reach a consensus on the most optimal material encouraging least dissipation in peri-implant hard tissues.