HISTOLOGICAL EVALUATION OF THE BIOCOMPATIBILITY AND BIOCONDUCTION OF A HYDROXYAPATITE-LIGNIN COMPOUND INSERTED IN RABBITS' SHINBONES

Objective. To evaluate the bio-compatibility and bone-conductivity properties of a hydroxyapatite-lignin compound implanted in rabbit's shinbone. Material and methods. 20 rabbits ( New Zealand race) were used for the experiments. In each animal, the left tibia was treated experimentally whereas the right tibia was used as experimental control. Using a manual drill, we bore a hole approximately 4mm diameter that reached the medullar canal. Each of these was subsequently treated with two tablets of the hydroxyapatite-lignin compound equivalent to 400 mg which were used to fill up the bone damage. The same surgical procedure was performed in the group of control, without using the compound. The histological evaluations were conducted at 8, 30, 60, 90 and 120 days post surgery based on four animals each time. Results. Comparison between experimental and control groups evidenced that at 30, 60, 90 and 120 days post-surgery there was an accelerated bone formation and extensive bone healing in the treated group. Conclusions. The hydroxyapatite-lignin compound allowed the growth of bone tissue from the edges to the center of the bone damage at a higher and more organized rate than in the control group. We also found the hydroxyapatite-lignin compound integrate well into the bone tissue, which - in addition to the observations presented above - allowed us to recommend it as a biocompatible and oseoconductor substitute in the case of bone damage.