Fracture Resistance and Finite Element Analysis of Single-piece PEEK Implant Restorative System Versus Titanium Single-piece Implant Restorative System: In-vitro Study

Abstract

Aim: To compare the fracture resistance and stress distribution of titanium one-piece implant restorative system with one-piece PEEK implant restorative system. Materials and Methods: 16 implants were divided into into two groups (n=8): titanium implants (Group Ti) and PEEK implants (Group P). All the samples received PEEK crowns simulating a lower premolar. Prefabricated one-piece titanium implants were scanned to be replicated into PEEK implants. Implants were imbedded in epoxy resin bases; the abutments were scanned, and the PEEK crowns were designed using a biogeneric copy on ExoCAD software. Crowns were pressed and cemented to their respective abutments. Fracture resistance test was assessed using a universal testing machine with a 5kN static load at crosshead speed of 1 mm/min. Finite Element Analysis (FEA) was conducted to evaluate stress distribution under various loading scenarios simulating oral conditions. Results: Group Ti showed significantly higher fracture resistance compared to the Group P (P < 0.001, Effect size = 2.519). Significant difference was found in failure modes between the groups (P < 0.001, Effect size = 1); Group P demonstrated higher prevalence of catastrophic failures in fixtures. FEA revealed higher Von Mises stresses in PEEK than in titanium under various loading conditions. Conclusion: Titanium showed superior fracture resistance when compared to PEEK. Titanium distributed stresses to supporting structures in a more favorable manner than PEEK. These findings highlight the limitations of PEEK as an implant material. Titanium remains a more suitable choice in terms of fracture resistance and stress distribution.