The interface of calcium-phosphate and glass-ceramic in bone, a structural analysis.

Bone bonding (BB) glass-ceramics and hydroxyapatite (HA) materials displayed considerable changes in their surface morphology after implantation which seem to be due to leaching, corrosion and active resorption by osteoclasts. Macrophages seem to play a central role in 'cleaning' and conditioning of the implant surface. Projections of the surface of BB glass-ceramics and HA serve as adhesion points for fibrillar structures. Thereafter, mineralization of fibres and interfibrillar spaces mediates and biomechanically stabilizes the interdigitation between surface elevations of implant and organic fibres and provides a tensile strength in the interface. Non-bonding (NB) glass-ceramic lacks considerable changes of surface morphology and displays a prolongated settlement of macrophages on their surfaces.