BONE-MARROW INDUCED OSTEOGENESIS IN HYDROXYAPATITE AND CALCIUM-CARBONATE IMPLANTS

In this experimental study, blocks of natural coral (calcium carbonate ) and its structurally similar derivate in the form of hydroxyapatite (calcium phosphate) were implanted in rat latissimus dorsi muscle with autogenous bone marrow to compare their bone-forming capability. A bl ock without marrow placed in the opposite latissimus muscle served as a control. The animals were killed at 3, 6 and 12 weeks and, in the hy droxyapatite group, also at 24 weeks. The sections were analysed histo logically and histomorphometrically. Bone was found only in implants c ontaining bone marrow. Bone formation was significantly (p < 0.05) hig her in coral than in hydroxyapatite implants at 3 weeks (10.8% versus 4.8%) and at 12 weeks (13.7% versus 6.3%, bone/total original block ar ea). At 12 weeks all the coral implants had lost their original struct ure, and the cross-sectional area of the block had diminished to 40% o f the original area. (C) 1996 Elsevier Science Limited.