Effectiveness of PEEK versus zirconia frameworks in fixed dental prostheses: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Zirconia has been widely used for frameworks of fixed dental prostheses (FDPs). Polyetheretherketone (PEEK) is a relatively new high-performance polymer. Currently, laboratory data comparing their performance are sparse and limited.

PURPOSE: The purpose of this systematic review was to compare the in vitro mechanical and interfacial performance of PEEK versus zirconia FDP frameworks.

MATERIAL AND

METHODS

The PubMed, ScienceDirect, Scopus, Cochrane Library and Google Scholar databases were searched up until March 2025. Studies were included if they were in vitro studies directly comparing PEEK and zirconia FDP frameworks. Outcomes reported by studies included fracture strength, marginal gap, and shear bond strength. Risk of bias assessments were completed using the Quality Assessment Tool for In Vitro Studies (QUIN). Meta-analyses (RevMan 5.4) were performed using random-effects models (α=.05). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework was used to determine certainty of evidence.

RESULTS

Fourteen studies were included in the review. Significantly greater fracture strength values were reported for zirconia than PEEK (pooled effect size -1.77; 95% CI -2.52 to -1.02; P<.001; I²=95%). A lower marginal gap was also shown for zirconia compared with PEEK, although PEEK had higher shear bond strength than zirconia. High methodological heterogeneity was seen among studies and the certainty of evidence was low.

CONCLUSIONS

Zirconia FDP frameworks exhibited higher fracture resistance while PEEK had more favorable bonding behavior in vitro. Results for marginal fit were varied. Since these were in vitro observations of material characteristics, these results should be viewed as hypothesis generating and not as predictors of clinical performance. Clinical research is necessary to validate these results.