Biomechanical Performance of PEEK and Graphene-Modified PMMA as Telescopic Removable Partial Denture Materials: A Nonlinear 3D Finite Element Analysis

Purpose: To assess stress and deformation in telescopic removable partial denture (RPD) frameworks manufactured with polyether ether ketone (PEEK) or graphene-modified polymethyl methacrylate (PMMA), as well as the stress of the underlying mucosa, via nonlinear 3D finite element analysis. Materials and Methods: The 3D model of a full mandible was merged with a 3D-scanned Kennedy Class I model with bilaterally missing molars. The tissues, the telescopic crowns, and the RPD framework were designed and created using dental CAD software. The model was duplicated, and two materials -PEEK and graphene-modified PMMA-were assigned to the telescopic crowns and their frameworks. A force of 200 N was applied perpendicularly to the molars, and constraints were placed in the mandibular ramus and the inferior border. The generated von Mises stress and deformation of the frameworks, as well as the stresses of the telescopic crowns and mucosa, were also assessed. Statistical analysis of the differences between the tested materials was conducted via an independent samples t test at (a = .05). Results: The von Mises stresses of the telescopic crowns and their frameworks in the graphene-modified PMMA model were significantly higher than in the PEEK model. In contrast, the deformation of the telescopic RPD framework of the PEEK model was significantly higher than the graphene-modified PMMA model. The stresses of the mucosa in both models showed an insignificant difference. Conclusion: PEEK material showed better biomechanical performance than the graphene-modified PMMA in telescopic RPDs.