Bone Surface Contact on a Thin-Film IBADHA Surface Modified Implant

Thin-film bioceramic (calcium- and phosphate-based) have been regarded as potential substitutes for surface modifications currently available due to the highly engineered microstructure and reduced thickness, which may enable controlled dissolution/absorption in-vivo enabling direct bone anchorage to the metallic substrate.Objective: to investigate the bone surface contact amount on an Ion Beam Assisted Deposited Hydroxyapatite (IBADHA) titanium alloy implant versus a non-surface-modified titanium alloy implant in a canine model. Methods: 64 implants were surgically placed in the animals’ tibiae and the model provided specimens that remained 2 and 4 weeks in vivo. The limbs were retrieved by sharp dissection and provided four blocks of bone each containing one implant. 32 non-decalcified blocks were subsequently reduced to thin sections with the implant in place and percent bone apposition was determined by length in length stereological measurements along the implant surface, under the assumption that the thin section is representative of the area and volume fraction of bone at the entire implant surface. The other 32 specimens were mounted and pulled out in a universal testing machine. Results: Analysis of variance revealed that time in-vivo did not have a significant effect on the percent bone apposition and that the control group had higher bone contact at the implant surface. The biomechanical pullout values were not significant between groups. Conclusions: results indicated that complete thin-film dissolution/absorption have not occurred at this times in-vivo, and that no weak link existed between coating and implant. The results also indicated enhanced mechanical properties of the bone around the IBADHA modified implants.