Early morphofunctional response of contact tissue after intraosal implantation in rabbit jaw of pure synthetic hydroxyapatite (HAp) bioceramic materials and HAp saturated with lidocaine

PURPOSE: The aim of this study was to evaluate early morphofunctional response of contact tissue to pure and saturated with lidocaine porous synthetic HAp ceramic implants inserted in holes of rabbit upper jaw. MATERIALS AND METHODS: Pure and saturated with lidocaine cylinders of porous HAp ceramics produced at Biomaterials R&D Laboratory of Riga Technical University were inserted into edentulous part of the upper jaw of 12 New Zealand male rabbits. After two weeks, blocks of soft tissue and bone were taken out. The sections done with EXACT Grunding system and from paraffin blocks were stained with haematoxylin/eosin and by use of biotin-streptavidin immunohistochemistry for transforming growth factor beta1 (TGFbeta1), fibroblast growth factor receptor 1 (FGFR1), interleukin 10 (IL10). Apoptosis was detected by TUNEL method. RESULTS: TGFbeta1 was equally expressed in the bone around HAp implants saturated with lidocaine and without lidocaine, while control sections did not show any expression of TGFbeta. In contacting bone tissue to pure HAp and HAp saturated with lidocaine as well in controls rich expression of FGFR1 was observed. In soft tissue of experimental samples also rich expression of FGFR1 was observed, although it was weak in control samples. IL10 had rich expression in all samples. The mean number of apoptotic cells was higher in samples with pure HAp, slightly decreased in samples HAp with lidocaine and significantly lower in controls. CONCLUSIONS: The expression of TGF beta1 confirms osteoinductive activity of HAp. Contact soft tissue to HAp showed rich FGFR1 expression, and weak in controls suggesting higher plasticity of connective tissue to implants in comparison with supportive tissue. Slightly lower apoptosis in samples of HAp with lidocaine gives evidence of indistinct influence of saturated with lidocaine HAp implants on development of programmed cell death.