Histologic study of incorporation and resorption of a bone cement–collagen composite: an in vivo study in the minipig

Objective Calcium phosphates are clinically established as bone defect fillers. They have the capability of osseoconduction and are characterized by a slow resorption process. The present study evaluated the suitability of a newly developed calcium phosphate cement modified with collagen type I. Study design The modified cement paste was inserted in differently designed defects of 10 minipigs. Further, an alveolar ridge augmentation was performed, applying the cement paste. The cement hardened in situ during the operation, forming a hydroxyapatite collagen composite. Animals were sacrificed after 1, 3, 6, 12, and 18 months. The tissue integration and resorption process was then evaluated using nondecalcified microsections. All animals were evaluated for histology. Results The implanted material showed osseoconductive characteristics. Resorption started from the edge of the defect zone, and bone substitution followed rapidly. Twelve months after placement of the cement, complete remodeling was observed. Conclusion It can be concluded that the applied hydroxyapatite-collagen cement composite shows good resorption and bone integration.