Effect of surface chemistry on the rate of osseointegration of sintered porous-surfaced Ti-6Al-4V implants.
OBJECTIVE
The effect of adding a thin sol-gel-formed calcium phosphate (CaP) coating to sintered porous-surfaced titanium alloy (Ti-6Al-4V) implants on rates of initial bone ingrowth was investigated.


METHODS
Control implants (as manufactured) and similar implants with sol-gel CaP coatings were randomly placed in distal femoral rabbit condyles (1 implant/leg). After healing for 6, 9, 12, and 16 days, 8 of 10 rabbits in each time group were assessed for maximum implant pullout force (N) and interface stiffness (N/mm). Selected extracted implants also were examined by secondary electron imaging to characterize affected surfaces. The implants of the remaining 2 rabbits in each group were examined by backscattered scanning electron microscopy (BSEM).


RESULTS
Significantly greater pullout forces and interface stiffness were found for CaP-coated implants at 6 and 9 days. At 6 days, BSEM revealed bone ingrowth on CaP-coated implants but not on control implants. Secondary electron imaging and BSEM observations also suggested greater bone ingrowth with CaP-coated porous implants at 9, 12, and 16 days.


CONCLUSIONS
Sol-gel-formed CaP surface films significantly enhance rates of bone ingrowth into sintered porous-surfaced implants.


CONCLUSIONS
This surface treatment may have a number of clinical benefits, including shortening the period prior to functional loading of such implants and improving treatment outcomes in situations of poor bone quality and/or quantity. (More than 50 references).
Institute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario, Canada.
Alex
A
Taché
Lu
L
Gan
Douglas
D
Deporter
Robert M
RM
Pilliar
D000497:Alloys; D000818:Animals; D002130:Calcium Phosphates / Q000737:chemistry; D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; D015921:Dental Implants; D017267:Dental Prosthesis Design; D005269:Femur; D005782:Gels; D020007:Implants, Experimental; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D016062:Porosity; D011817:Rabbits; D018709:Statistics, Nonparametric; D013499:Surface Properties; D014025:Titanium
D000497:Alloys; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; D015921:Dental Implants; D005782:Gels; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C031462:titanium alloy (TiAl6V4); C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; D014025:Titanium; C485829:calcium phosphate, dibasic, anhydrous