title: Use of injectable calcium-phosphate cement for the fixation of titanium implants: an experimental study in goats.
abstract: This in vivo study evaluated the fixation of two types of titanium implants with the use of an injectable calcium-phosphate (CaP) cement. The cement was either used to create a cement mantle (Type A implant) or as an additive to press-fit placed titanium plasma sprayed implants (Type B implant). The implants were placed in trabecular bone of the medial femoral condyle of goats and left in place for 2 and 10 weeks. Mechanical evaluation of the implant fixation was done by torque testing. This showed that for the Type A implants the calcium-phosphate cement's performance was significantly inferior (P < 0.05) to that of polymethylmethacrylate cement fixation. For the two-week Type B implants a significant increase (P < 0.05) in failure load was found for calcium-phosphate cemented implants compared with just press-fitted Type B implants. Histological evaluation revealed that for Type A implants, failure during torque testing occurred at the implant-cement interface. In contrast, for Type B implants, failure occurred in the bone-implant interface for press-fit-placed devices and in the cement layer for CaP-cemented devices. Further, the CaP cement was found to be overgrown with new formed bone already after 2 weeks of implantation. The cement showed resorption due to regular bone remodeling. On the basis of these observations, it was concluded that the use of injectable CaP cement might facilitate earlier loading of press-fit inserted titanium implants. Nevertheless, the results have to be confirmed in dynamical mechanical as well as loaded in vivo studies.
authors.affiliation: Department of Biomaterials, College of Dental Science, University Medical Center Nijmegen, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: E M
authors.initials: EM
authors.lastname: Ooms
authors.forename: J G C
authors.initials: JG
authors.lastname: Wolke
authors.forename: J P C M
authors.initials: JP
authors.lastname: van der Waerden
authors.forename: J A
authors.initials: JA
authors.lastname: Jansen
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001843:Bone Cements; D002130:Calcium Phosphates / Q000008:administration & dosage; D005260:Female; D006041:Goats; D007267:Injections; D008422:Materials Testing; D016348:Osseointegration; D019904:Polymethyl Methacrylate; D019736:Prostheses and Implants; D013997:Time Factors; D014025:Titanium
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; D019904:Polymethyl Methacrylate; C020243:calcium phosphate; D014025:Titanium; C485829:calcium phosphate, dibasic, anhydrous