Hydroxyapatite and carbon coatings for fixation of unloaded titanium implants

• The aim of this study was to investigate the interaction between bone and pure titanium, titanium coated with hydroxyapatite (HA), and titanium coated with carbon in a rat femur model. In 25 rats, the medullary cavity of both femurs was entered by an awl from the trochanteric area. With steel burrs it was successively reamed to a diameter of 2.0 mm. Nails with a diameter of 2.0 mm and with a length of 34 mm were inserted in a random manner; either a pure titanium nail, a titanium nail entirely plasma-sprayed with a 75-100-microm layer of HA or a titanium nail coated with 2-10-microm carbon. The surface roughness of the pure titanium was characterized by Ra 2.6 microm and Rt 22 microm. Ra of HA was 7.5 microm and Rt 52 microm, and of carbon Ra was 0.4 microm and Rt 4.0 microm. Twelve rats were randomized to a follow up of 8 weeks, and the remaining 13 rats were followed for 16 weeks. At sacrifice both femora were dissected free from soft tissues and then immersed in fixative. A specimen slice of about 5 mm thickness was prepared from the subtrochanteric region with a water-cooled band-saw. Sample preparation for un-decalcified tissue followed the internal guidelines at the laboratories of Biomaterials/Handicap Research. At 8 weeks the median bone bonding contact of the implants was 43% (range 0-74) in the titanium group, 39% (0-75) in the HA group, and 3% (0-59) in the carbon group. At 16 weeks the corresponding figures were 58% (0-78) in the titanium group, 51% (15-75) in the HA group, and 8% (0-79) in the carbon group. In conclusion, we found great variability in bone bonding contact. In general, carbon-coated nails had reduced bone bonding contact both at 8 and at 16 weeks as compared to pure titanium or titanium coated with hydroxyapatite.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Kirurgi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Surgery (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine (hsv//eng)

Nyckelord

Analysis of Variance

Animals

Bone Nails

Carbon/chemistry

Coated Materials

Biocompatible

Disease Models

Animal

Femur/*surgery

Hydroxyapatites/chemistry

Male

Materials Testing

Osseointegration/*physiology

Probability

*Prostheses and Implants

Rats

Rats

Wistar

Sensitivity and Specificity

*Titanium

Medicin

Publikations- och innehållstyp

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