title: Polyetheretherketone-a suitable material for fixed dental prostheses?
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Prosthodontics, Munich Dental School, Munich, Germany.
authors.forename: Bogna
authors.initials: B
authors.lastname: Stawarczyk
authors.forename: Florian
authors.initials: F
authors.lastname: Beuer
authors.forename: Timea
authors.initials: T
authors.lastname: Wimmer
authors.forename: Dirk
authors.initials: D
authors.lastname: Jahn
authors.forename: Beatrice
authors.initials: B
authors.lastname: Sener
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Roos
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Schmidlin
mesh_terms: D001577:Benzophenones; D001672:Biocompatible Materials / Q000737:chemistry*; D003801:Dental Veneers; D007659:Ketones / Q000737:chemistry*; D008422:Materials Testing; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers; D013314:Stress, Mechanical
chemical_list: D001577:Benzophenones; D001672:Biocompatible Materials; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols
keywords: PEEK; bond strength; conditioning; contact angles; fracture load; polyetheretherketone; roughness