Poly-Ether-Ether-Ketone (PEEK) Removable Partial Dentures: A Scoping Review

This scoping review aims to comprehensively assess the existing evidence from both clinical and in vitro studies concerning removable partial dentures (RPD) made from poly-ether-ether-ketone (PEEK) to identify current research gaps and enhance the understanding of PEEK’s viability as a material for RPD. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews was applied. A search was made using PubMed, Web of Science, Elsevier’s Scopus, ProQuest and Springer Link databases for articles in the English language up to November 2023, focusing on case reports, clinical, and in vitro studies. A total of 33 studies were included in the analysis, which consisted of 4 case reports, 6 clinical studies, and 23 in vitro studies. Clinical studies predominantly examined patient satisfaction post-PEEK RPD insertion, framework accuracy, dimensional changes in residual ridges, and fungal/bacterial adhesion to PEEK. In vitro studies emphasised retentive force clasps (12 studies), accuracy and fitness (5 studies), material staining effects (3 studies), and diverse surface treatments (3 studies). The current body of evidence reveals a scarcity of clinical studies investigating PEEK as an RPD framework. In vitro studies primarily focused on assessing material retentive forces, with limited attention given to accuracy, surface treatment, and staining of denture base materials. Future research should address these gaps, exploring aspects such as adhesion and biofilm formation (e.g. Candida albicans) on RPD surfaces. Rigorous, well-designed clinical trials and expanded in vitro investigations are essential to establish PEEK RPD as definitive prostheses for partially edentulous patients.