title: Osseointegration of alumina with a bioactive coating under load-bearing and unloaded conditions.
abstract: The aim of the study was to evaluate the osseointegration of Al(2)O(3) coated with a bioactive glass ceramic (BioveritI), in a load-bearing implant model in sheep in comparison to uncoated Al(2)O(3) and to a minimally loaded situation. Both types of implants were inserted into the proximal tibia (load-bearing model) and in a drill hole defect into the tibia diaphysis (minimally loaded model). Under load-bearing conditions, the coating resulted in significantly higher interfacial shear strength and a high amount of mineralized bone in direct contact to the implant surface. In contrast, the uncoated Al(2)O(3) was surrounded by a thick connective tissue layer corresponding to low interfacial shear strength. In the minimally loaded model, however, there was rather a tendency of lower interfacial shear strength in the case of the coated implants. This finding corresponds to the histological results, which showed mineralized bone in the interface of uncoated Al(2)O(3), whereas in the case of the coated implants a thin layer of osteoid was observed. It was suggested that the osseointegration of Al(2)O(3) could be improved by the coating under load-bearing conditions, under which uncoated Al(2)O(3) ceramics cannot directly bind to bone.
authors.affiliation: Institute of Orthopaedic Research and Biomechanics, University of Ulm, Helmholtzstrasse 14, 89081 Ulm, Germany. anita.ignatius@medizin.uni-ulm.de
authors.forename: Anita
authors.initials: A
authors.lastname: Ignatius
authors.forename: Manfred
authors.initials: M
authors.lastname: Peraus
authors.forename: Sandra
authors.initials: S
authors.lastname: Schorlemmer
authors.forename: Peter
authors.initials: P
authors.lastname: Augat
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Burger
authors.forename: Stefan
authors.initials: S
authors.lastname: Leyen
authors.forename: Lutz
authors.initials: L
authors.lastname: Claes
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D005260:Female; D020007:Implants, Experimental; D008422:Materials Testing; D010012:Osteogenesis; D033081:Shear Strength; D012756:Sheep; D013978:Tibial Fractures / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome; D016474:Weight-Bearing
chemical_list: C067324:Bioverit; D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D000537:Aluminum Oxide