Systematic Review Comparing PEEK to Conventional Removable Prosthodontics

Abstract

Statement of the Problem: A significant research gap exists in the comparative evidence regarding the clinical and laboratory performance of Polyetheretherketone (PEEK) versus Cobalt-Chromium alloys in removable partial dentures. Specifically, current literature lacks robust data concerning fit accuracy, retention, clinical performance, patient-reported outcomes, and associated complications.  Purpose: This systematic review evaluates the clinical and laboratory performance of PEEK as a material for fabricating frameworks and clasps in comparison to cobalt-chromium alloys for removable partial dentures. Materials and Methods: Two independent reviewers systematically searched PubMed, Scopus, and Web of Science databases for English-language articles published between 2020 and 2025 to identify in vitro and clinical studies that directly compared PEEK and cobalt-chromium alloy in fabricating removable partial denture frameworks and clasps.  Results: From 339 studies identified, 15 met inclusion criteria: 11 in vitro and 4 clinical studies. Data were extracted on participant numbers, prosthesis types, arch location, follow-up duration, fit accuracy, retention, and patient-reported outcome measures. Among the 11 in vitro studies, four evaluated fit accuracy, four assessed retention, one examined both outcomes, and two investigated other mechanical properties. PEEK frameworks demonstrated superior fit accuracy compared to cobalt-chromium alloys, while cobalt-chromium showed higher initial retention values however PEEK exhibited better retention stability over time. All four clinical trials reported comparable patient satisfaction and periodontal health outcomes between PEEK and cobalt-chromium frameworks, with no technical failures observed in PEEK groups. Conclusions: Clinical studies and in vitro research comparing removable partial denture frameworks fabricated from PEEK material with those fabricated from cobalt-chromium alloy remain scarce and limited. However, current evidence indicates better fit for PEEK frameworks, with the mean silicone wafer weight recorded at 0.121 g for PEEK frameworks, compared to 0.154 g for conventionally cast cobalt-chromium frameworks and 0.215 g for cobalt-chromium frameworks fabricated via selective laser melting , indicating superior dimensional accuracy for PEEK over both cobalt-chromium fabrication techniques. Furthermore, it was found that the level of retention and patient satisfaction with PEEK frameworks matches their counterparts in cobalt-chromium frameworks.