Bone reaction to nano hydroxyapatite modified titanium implants placed in a gap-healing model
Journal article, 2008

Nanohydroxyapatite materials show similar chemistry to the bone apatite and depending on the underlying topography and the method of preparation, the nanohydroxyapatite may simulate the specific arrangement of the crystals in bone. Hydroxyapatite (HA) and other CaP materials have been indicated in cases in which the optimal surgical fit is not achievable during surgery, and the HA surface properties may enhance bone filling of the defect area. In this study, very smooth electropolished titanium implants were used as substrata for nano-HA surface modification and as control. One of each implant (control and nano HA) was placed in the rabbit tibia in a surgical site 0.7 mm wider than the implant diameter, resulting in a gap of 0.35 mm on each implant side. Implant stability was ensured by a fixating plate fastened with two side screws. Topographical evaluation performed with an optical interferometer revealed the absence of microstructures on both implants and higher resolution evaluation with AFM showed similar nanoroughness parameters. Surface pores detected on the AFM measurements had similar diameter, depth, and surface porosity (%). Histological evaluation demonstrated similar bone formation for the nano HA and electropolished implants after 4 weeks of healing. These results do not support that nano-HA chemistry and nanotopography will enhance bone formation when placed in a gap-healing model. The very smooth surface may have prevented optimal activity of the material and future studies may evaluate the synergic effects of the surface chemistry, micro, and nanotopography, establishing the optimal parameters for each of them.




bone defect

in vivo test



Luiz Meirelles

University of Gothenburg

Tomas Albrektsson

University of Gothenburg

Per Kjellin

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Anna Arvidsson

University of Gothenburg

Victoria Franke Stenport

University of Gothenburg

Martin Andersson

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Fredrik Currie

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Ann Wennerberg

University of Gothenburg

Journal of Biomedical Materials Research - Part A

1549-3296 (ISSN)

Vol. 87 3 624-631

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