Polyetheretherketone materials for removable partial denture frameworks: an integrative review

Polyetheretherketone (PEEK) resin is a high-performance thermoplastic polymer that has been introduced as a possible candidate to replace metallic components in dental prostheses. The objective of this integrative review was to compare, through analysis of studies in the literature, the mechanical performance of removable partial denture frameworks and clasps manufactured with PEEK with the performance of cobalt-chromium (Co-Cr) frameworks and clasps. The guiding question was, "Does the use of PEEK as a substitute for Co-Cr alloys for the construction of removable partial denture frameworks result in better mechanical properties?" The PubMed/ MEDLINE, Embase, Web of Science, Scopus, and SciELO databases were searched for articles published through October 2021. The JBI Critical Appraisal Checklist for Quasi-Experimental Studies was used to assess the methodologic quality of the selected in vitro studies. A total of 208 articles were identified. After the exclusion of duplicates and articles that did not meet the inclusion criteria, 7 studies- -4 in vitro and 3 three-dimensional finite element analyses- -published between 2012 and 2021 were included in the integrative review. The appraisal checklist revealed that the reviewed studies had a low risk of bias and high methodologic quality. The results of the review showed that PEEK alloys have adequate mechanical properties for use in clasps and removable partial denture frameworks, but Co-Cr alloys exhibit better mechanical properties and are more suitable in most circumstances.