Polyetheretherketone-a suitable material for fixed dental prostheses?

Abstract

Objectives: To study the surface properties of polyetheretherketone (PEEK) and its bond strength with two veneering resins after different conditioning methods as well as fracture load of PEEK three-unit fixed dental prostheses (FDPs).

Methods: Two hundred and twenty five PEEK specimens were fabricated and divided into five groups: no treatment (A), etching with 98% sulfuric acid for 1 min (B), air-abrasion for 10 s with either 50 or 110 μm alumina (C and D, respectively), and silica coating using the Rocatec System (E). On 15 specimens of each conditioning method, contact angle and surface roughness were determined. The remaining 150 specimens of each conditioning method were divided into two groups for the veneering procedure with the composites Gradia (GC Europe) and Sinfony (3M ESPE). Shear bond strength (SBS) was measured and failure types were assessed. In addition, 15 FDPs were milled and the fracture load was tested. Data were analyzed using descriptive statistics, one-way ANOVA (Scheffé test), two sample Student's t-test, and Weibull statistics (p < 0.05).

Results: Silica-coated PEEK surfaces showed the highest wettability. The highest roughness and lowest contact angles were observed for 110 μm air-abraded and silica-coated PEEK surfaces. The highest SBS values were, however, achieved in the acid-etched group. PEEK three-unit FDPs showed a mean fracture load of 1383 N with a plastic deformation starting approximately at 1200 N.

Conclusions: Acid etching should be applied when PEEK is used as substructure material and composite veneering material is applied. In this combination, PEEK might be a suitable material for FDPs, especially in load-bearing areas.

Keywords: PEEK; bond strength; conditioning; contact angles; fracture load; polyetheretherketone; roughness.