title: Effect of different surface pre-treatments and luting materials on shear bond strength to PEEK.
abstract: OBJECTIVE
  To assess the bonding potential of a universal composite resin cement and an adhesive/composite system to differently pre-treated PEEK surfaces.
  
  
  METHODS
  One hundred and fifty PEEK disks were embedded in epoxy resin, polished (P4000 grit) and treated as follows (n=30/group): (A) no treatment, (B) acid etching with sulfuric acid (98%) for 1 min, (C) sandblasting for 10s with 50 microm alumina, (D) sandblasting for 10s with 110 microm alumina and (E) silica coating using the Rocatec system (3M ESPE). Polished and sandblasted (50 microm alumina) cp titanium (grade 4) served as a control. Acrylic hollow cylinders were either luted with a universal composite resin cement (RelyX Unicem) or an unfilled resin (Heliobond) and a hybrid composite (Tetric) to the specimens. Bond strength was measured in a shear test and failure modes were assessed. Statistic analysis was performed with one-way ANOVA followed by a post hoc Scheffé test and unpaired t-tests.
  
  
  RESULTS
  With the universal composite resin cement, no bond could be established on any PEEK surfaces, except specimens etched with sulfuric acid (19.0+/-3.4MPa). Shear bond strength to titanium was significantly lower (8.7+/-2.8MPa, p<0.05). Applying the adhesive/composite system, shear bond strength values on pre-treated PEEK ranged from 11.5+/-3.2MPa (silica coating) to 18.2+/-5.4MPa (acid etched) with no statistically significant differences (p>0.05). No bond was obtained on the polished surface.
  
  
  CONCLUSIONS
  Bonding to PEEK is possible when using a bonding system. No adherence can be achieved with the tested universal composite resin cement except on an etched surface. The results strongly encourage further research in PEEK application in dentistry.
authors.affiliation: Clinic for Preventive Dentistry, Periodontology and Cariology, University of Zurich, Center for Dental and Oral Medicine, Plattenstrasse 11, Zurich, Switzerland. patrick.schmidlin@zzmk.uzh.ch
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Schmidlin
authors.forename: Bogna
authors.initials: B
authors.lastname: Stawarczyk
authors.forename: Marco
authors.initials: M
authors.lastname: Wieland
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
authors.forename: Christoph H F
authors.initials: CH
authors.lastname: Hämmerle
authors.forename: Jens
authors.initials: J
authors.lastname: Fischer
mesh_terms: D000134:Acid Etching, Dental; D000179:Acrylates / Q000737:chemistry; D000180:Acrylic Resins / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry; D001577:Benzophenones; D001672:Biocompatible Materials / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D045662:Dental Etching; D003775:Dental Polishing / Q000379:methods; D006801:Humans; D007659:Ketones / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013464:Sulfuric Acids / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry
chemical_list: D000179:Acrylates; D000180:Acrylic Resins; D001577:Benzophenones; D001672:Biocompatible Materials; D003188:Composite Resins; D003738:Dental Cements; D007659:Ketones; D011108:Polymers; C483701:Rely X Unicem; D019279:Resin Cements; C076811:Rocatec; D013464:Sulfuric Acids; C090969:Tetric; C063834:polyetheretherketone; D011092:Polyethylene Glycols; D012822:Silicon Dioxide; C040415:heliobond; D014025:Titanium; D000537:Aluminum Oxide; C033158:sulfuric acid