Stress distribution in bone around an implant‑supported three‑unit fixed dental prosthesis using two different computer‑aided designing/ computer‑aided milling provisional crown materials: Milled polymethylmethacrylate and milled polyetheretherketone – A

Abstract

Background: Occlusal loading of osseointegrated implants is believed to be an essential
determining factor in the long‑term success of an implant treatment. Numerous studies have
been conducted on the evaluation of stress distribution by definitive restoration materials for
Implant‑supported fixed prosthesis, but very few have evaluated provisional restoration materials
for the same. This study aims to evaluate the influence of provisional restoration material – Milled
Polymethylmethacrylate (PMMA) and Milled Polyetheretherketone (PEEK), over stress distribution
on the peri‑implant bone around an implant‑supported three‑unit, fixed dental prosthesis using
finite element analysis method.
Materials and Methods: Three‑dimensional models of a pair of bone‑level implant system and
titanium base abutments were created using the standard tessellation language data of original implant
components. A bone block representing the mandibular posterior area was created, and the implants
were placed in the bone block with 100% osseointegration in the 2nd premolar to 2nd molar region.
A superstructure of an implant‑supported 3‑unit bridge was modeled on top of the abutments, each
crown to be 8 mm in height and with an outer diameter of 6 mm in 2nd premolar region and 10 mm
in 1st molar and 2nd molar region. Two different models were created according to combinations of
provisional restoration materials, namely, Milled PMMA and Milled PEEK based on. In each model,
the implants were loaded vertically (300 N) and obliquely (150 N at 30°). The stress distribution in
the cortical bone, cancellous bone, and implant was evaluated through the von Mises stress analysis.
Results: The results showed no difference in stress distribution due to the different provisional
restorations – Milled PMMA and Milled PEEK. In addition, the vertical load resulted in higher stress
values in the implant components, cortical bone, and cancellous bone in both PEEK and PMMA
models as compared to oblique loading.
Conclusion: The new polymer, PEEK was seen to provide comparable stress generation in the
current study without exceeding the physiological limits of peri‑implant bone. Thus, it can be 

considered as a good alternative to PMMA resin as a provisional crown material since it provides
certain additional benefits.
Key Words: Finite element analysis, implant dentistry, polyetheretherketone, poly methyl methacrylate, provisionalization