A comparison of femoral and mandibular animal models for the evaluation of HA-coated implants.

The application of hydroxylapatite coatings promises marked improvement in the rapidity and durability of osseointegration for both dental and orthopedic metallic implants. Standard methods for the in vivo assessment of the performance of experimental implants include canine mandibular and femoral transcortical implantations. This study compared the results of the two procedures by use of similar HA-coated titanium implants. The results indicate that the rapidity of osseointegration and the maximum attachment strength for mandibular dental implants approximate those of the femoral transcortical implants, especially at longer post-operative intervals. We conclude that the two models are comparable for the purpose of evaluating the performance of this type of implant and can be used interchangeably by dental and orthopedic implant designers. HA-coating of titanium implants provides extensive osseointegration in both mandibular and long-bone models, with similar mechanical attachment strengths and histologic appearance.