The Effects of using PEEK Coping and Different Restorative Materials on the Stress Distribution in Tooth and Implant- supported Prostheses under Static Loading: 3D FEA.

Abstract

This study was designed to evaluate the influence of utilizing Polyetheretherketone (PEEK) coping and three different dental restorative materials in the success of tooth and implant-supported fixed partial dentures (TISFPD) in the maxillary posterior region, under static loading by 3-Dimensional Finite Element Analysis (3D FEA). Six 3D FEA models were designed assuming the extraction of maxillary first and second molars. Bone, implant, abutment, PEEK coping, second premolar, periodontal ligament (PDL) and six 3-unit TISFPD with different restorative materials [Porcelain-Fused-to-Metal (PFM), PEEK-Composite (PC), Monolithic Zirconia (MZ)] were modeled. Then, PEEK copings were modeled to be cemented onto the implants as a double-crown system for the first three groups (PFMPEEK, PCPEEK and MZPEEK) whereas, the next three groups (PFM, PC, MZ) excluded a PEEK coping in their designs. The prostheses were loaded twice, vertically and obliquely. From the determined points, 250 N for vertical loading (0o to the long axis) and 200 N for the oblique loading (30o to the long axis) were applied. Von Mises tension, maximum and minimum principal tension value criterias were analyzed. Regardless of the material used for suprastructure, the maximum average stress was reduced by using PEEK coping. Considering the maximum stress distribution, PC appeared to have the highest stresses on the cortical bone, implant and screw. Additionally, the von Mises stresses formed in the PDL for each model were lower when PEEK coping was included in the design of the TISFPD, reducing the risk of intrusion. The stress distribution was positively affected by the PEEK coping in TISFPD design, reducing bone resorption and failure. This elastic material used generated lower stresses in the bone and implant, while no significant effect was found on stresses around natural teeth.