Short-term bone response to titanium implants coated with thin radiofrequent magnetron-sputtered hydroxyapatite in rabbits.
BACKGROUND
It has been suggested that calcium phosphate (CaP) coatings initiate faster bone growth around implants. A major concern about the viable use of these coatings has been their biologic performance related to the coating characteristics.


OBJECTIVE
The purpose of this study was to investigate the early bone response to micron- and submicron-thick hydroxyapatite (HA) coatings in cortical and trabecular bone.


METHODS
CaP coatings were manufactured by magnetron sputtering. Heat treatment was subsequently used to increase the crystallinity of the coatings. Coatings were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES), and stylus profilometry. Four types of CaP-coated implants were used (0.1 microm and 2.0 microm amorphous; 0.1 microm and 2.0 microm crystalline); uncoated machined commercially pure titanium implants served as controls. Four hundred eighty implants were randomly placed in 60 rabbits. Ten animals were followed up for 1 week, 10 for 3 weeks, and 40 for 6 weeks. The bone response was histomorphometrically evaluated.


RESULTS
Coatings with a CaP ratio very close to that of HA were produced. Crystalline coatings significantly improved the early bone-implant contact whereas the amorphous-coated implants behaved similarly to uncoated titanium.


CONCLUSIONS
Crystalline CaP coatings 100 nm thick on titanium implants elicited an improved early bone response compared with that of uncoated titanium implants. No further improvement in the bone response was observed with 2 microm coatings.
Mohammadi
Shams
S
Department of Biomaterials, Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden.
Esposito
Marco
M
Hall
Jan
J
Emanuelsson
Lena
L
Krozer
Anatol
A
Thomsen
Peter
P
D000818:Animals; D020099:Coated Materials, Biocompatible; D018360:Crystallography, X-Ray; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017886:Durapatite; D005260:Female; D005269:Femur; D020007:Implants, Experimental; D016348:Osseointegration; D011817:Rabbits; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013977:Tibia; D014025:Titanium
D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D017886:Durapatite; D014025:Titanium