ULTRASTRUCTURAL-STUDY OF THE OSTEOINTEGRATION OF BIOCERAMICS (WHITLOCKITE AND COMPOSITE BETA-TCP PLUS COLLAGEN) IN RABBIT BONE

Study examines the osteointegration of two porous ceramic implants, be ta-tricalcium phosphate (beta-TCP) and a composite (beta TCP-collagen) , in femur and tibias of 20 New Zealand white rabbits, which were sacr ificed 1 week and 1, 4, and 12 months postimplant so that radiological , optical microscopic, and ultrastructural studies could be carried ou t. The results show a progressive degradation and resorption of both i mplant materials by means of a macrophagic reaction, which is at its m ost intense 1 month postimplant. The materials are substituted by newl y formed bone tissue starting at the host bone-implant interface, the substitution being almost total by the end of the study, although less completely and earlier than in the case of the composite. Both materi als can be considered as potential substitutes for bone tissue since t hey are biocompatible, bioreabsorbable, and osteogenic.