Bone response to three different chemical compositions of fluorcanasite glass-ceramic

The aim of this study was to evaluate the bone response to three fluorcanasite glass-ceramic compositions with different solubilities (K3, K5, and K8) after implantation in a femur rabbit model. Fluorcanasite glass-ceramic rods were implanted bilaterally in the mid-shafts rabbit femurs. Implants were harvested at 8 and 12 weeks and prepared for histological and histomorphometric analyses at the light microscope level. Bioglass 45S5 rods were used as a control material. At 8 weeks, all fluorcanasite glass-ceramics were entirely surrounded by a nonmineralized connective tissue. At 12 weeks, reduced areas of bone tissue were observed in the cortical area in direct contact with the K3 and K5 fluorcanasite glass-ceramics compared to Bioglass 45S5, whereas no bone tissue was observed in direct contact with the K8 surface. Bone-to-implant contact in the cortical area was affected by the material chemical composition and ranked as follows: Bioglass 45S5>K3>K5>K8 (p=0.001). In the bone marrow, a layer of fibrous connective tissue formed in direct contact with the fluorcanasite glass-ceramics and Bioglass 45S5, and only rarely exhibited contact osteogenesis. All the fluorcanasite glass-ceramics appeared to degrade in the biological environment. The solubility ratio did not alter significantly the biological reply of the fluorcanasite glass-ceramics in vivo. Further modifications of the chemical composition of the fluorcanasite glass-ceramic are required to increase the stability of the material in vivo.