Porous Titanium Implants with and without Hydroxyapatite Coating: A Biomechanical Study

ABSTRACT Canine cancellous bone titanium porous coated implants with and without hydroxyapatite coating were compared. Samples had cylindrical shape, length was 22 mm, diameter 5 +/- 0.3 mm. Implants bead size was 500-700 micron. Seven samples were coated with Hydroxyapatite (HA) by air plasma spray and equal number of uncoated implants were used as the controls. Samples were press fit in the proximal femoral cancellous bone of 7 dogs. Animals were sacrificed after 12 weeks. No significant differences were observed between the HA coated and uncoated implants in the push-out test results. Significant greater bone apposition to the implant surface was observed in the HA coated samples when compared to the uncoated ones. The histological analysis of the push-out samples shows that the mechanical failure occurred mostly by trabecular fractures in both HA-coated and uncoated samples. In HA-coated samples, detachments and fractures of HA from the metal were also visible.