title: Biomechanical evaluation and surface characterization of a nano-modified surface on PEEK implants: a study in the rabbit tibia.
abstract: Polyether ether ketone (PEEK) is today frequently used as a biomaterial in different medical operations due to its excellent mechanical and chemical properties. However, the untreated surface of PEEK is bioinert and hydrophobic, and it does not osseointegrate in its pure form. The aim of this study was to evaluate a unique nano-modified surface of PEEK with respect to osseointegration. Forty-eight threaded, non-cutting PEEK implants were inserted bilaterally in the tibia of 24 rabbits. Half of the implants (n=24) were coated with nanocrystalline hydroxyapatite (test) and the remaining implants (n=24) were left uncoated (control). Half of the animals (n=12) were euthanized after 3 weeks of healing and the remaining (n=12) after 12 weeks. The implant retention was measured with a removal torque apparatus. Surface analysis was performed with interferometry, scanning electron microscopy, and X-ray photon spectroscopy to relate the removal torque to the applied surface. The test implants revealed a significantly higher retention after 3 weeks (P=0.05) and 12 weeks (P=0.028) compared to controls. The result of the present study proves that the addition of nanocrystalline hydroxyapatite coating to PEEK surfaces significantly increases its removal torque and biocompatibility.
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Pär
authors.initials: P
authors.lastname: Johansson
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
authors.affiliation: Promimic AB, Göteborg, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Kjellin
authors.affiliation: Promimic AB, Göteborg, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Currie
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Bruno Ramos
authors.initials: BR
authors.lastname: Chrcanovic
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
mesh_terms: D000818:Animals; D001577:Benzophenones; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D017886:Durapatite / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D007659:Ketones / Q000737:chemistry / Q000494:pharmacology*; D008297:Male; D049329:Nanostructures / Q000737:chemistry*; D016348:Osseointegration / Q000187:drug effects*; D011092:Polyethylene Glycols / Q000737:chemistry / Q000494:pharmacology*; D011108:Polymers; D011817:Rabbits; D013499:Surface Properties; D013977:Tibia / Q000601:surgery*; D019415:Torque
chemical_list: D001577:Benzophenones; D001672:Biocompatible Materials; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols; D017886:Durapatite
keywords: hydroxyapatite; nanotopography; polyether ether ketone; removal torque