title: The removal of Al2O3 particles from grit-blasted titanium implant surfaces: effects on biocompatibility, osseointegration and interface strength in vivo.
abstract: For the improvement of surface roughness and mechanical interlocking with bone, titanium prostheses are grit-blasted with Al(2)O(3) particles during manufacturing. Dislocated Al(2)O(3) particles are a leading cause of third-body abrasive wear in the articulation of endoprosthetic implants, resulting in inflammation, pain and ultimately aseptic loosening and implant failure. In the present study, a new treatment for the removal of residual Al(2)O(3) particles from grit-blasted, cementless titanium endoprosthetic devices was investigated in a rabbit model. The cleansing process reduces residual Al(2)O(3) particles on titanium surfaces by up to 96%. The biocompatibility of the implants secondary to treatment was examined histologically, the bone-implant contact area was quantified histomorphometrically, and interface strength was evaluated with a biomechanical push-out test. Conventional grit-blasted implants served as control. In histological and SEM analysis, the Al(2)O(3)-free implant surfaces demonstrated uncompromised biocompatibility. Histomorphometrically, Al(2)O(3)-free implants exhibited a significantly increased bone-implant contact area (p=0.016) over conventional implants between both evaluation points. In push-out testing, treated Al(2)O(3)-free implants yielded less shear resistance than conventional implants at both evaluation points (p=0.018). In conclusion, the new surface treatment effectively removes Al(2)O(3) from implant surfaces. The treated implants demonstrated uncompromised biocompatibility and bone apposition in vivo. Clinically, Al(2)O(3)-free titanium prostheses could lead to less mechanical wear of the articulating surfaces and ultimately result in less aseptic loosening and longer implant life.
authors.affiliation: Endogap-Joint Replacement Institute, Klinikum Garmisch-Partenkirchen, Garmisch-Partenkirchen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Rüger
authors.forename: Tobias J
authors.initials: TJ
authors.lastname: Gensior
authors.forename: Christian
authors.initials: C
authors.lastname: Herren
authors.forename: Matthias
authors.initials: M
authors.lastname: von Walter
authors.forename: Christina
authors.initials: C
authors.lastname: Ocklenburg
authors.forename: Rudolf
authors.initials: R
authors.lastname: Marx
authors.forename: Hans-Josef
authors.initials: HJ
authors.lastname: Erli
mesh_terms: D000537:Aluminum Oxide / Q000302:isolation & purification*; D000818:Animals; D001672:Biocompatible Materials; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D011817:Rabbits; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D014025:Titanium; D000537:Aluminum Oxide