Tricalcium Phosphate Granules Research Articles

Behaviour of tricalcium phosphate and hydroxyapatite granules in sheep bone defects

Granules of hydroxyapatite (HA) and tricalcium phosphate (TCP) were implanted in separate holes drilled in mandibular bone of sheep to check the bone growth and in vivo behaviour of the materials. The experiment was performed in three sheep, killed respectively at 4, 8,12 month. Samples of bone with the materials were explanted, microradiographed and sectioned to evaluate the interface under optical and electron scanning electron microscope. The hole, left empty as a reference, showed no full repair; whereas 4 month after implantation the TCP granules induce total repair of the hole. HA granules crumbled and no new bone induction was seen even 12 month after implantation.

Bone Formation in Tricalcium Phosphate‐Filled Periodontal Intrabony Lesions. Histological Observations in Humans

The capacity of a tricalcium phosphate (TCP) ceramic to promote bone formation after grafting in intrabony defects was studied in humans. Five biopsies were collected from 4 patients during reentry surgery 16 to 40 months after implantation. They were processed without demineralization for histological examination. In the less mature samples, the grafted material was surrounded by a highly fibrous, highly cellular, and poorly vascularized connective tissue. Howship's lacuna-like cavities were clearly visible at the surface of the material. They contained resorbing mononuclear phagocytes. At a more mature stage, TCP granules were embedded in an acellular fibrous material which underwent mineralization from the medullary spaces towards the granules. The bone formed was subsequently remodeled. The implanted material itself was progressively modified. It first acquired the staining appearance of bone. After its structure became loose and vacuolated, it was invaded by cells and vessels. The present data indicate that TCP has osteogenic potential and is subject to degradation. Unlike in experimental wounds, these processes are of long duration in human defects.

Enhanced Stabilization of Porous-coated Metal Implants with Tricalcium Phosphate Granules

Tricalcium phosphate (TCP) granules were tested as a possible alternative to bone graft as an interposition material to stabilize porous-coated metal implants in overreamed femoral intramedullary canals in dogs in vitro and in vivo. TCP granules provided as much stability as bone graft or a press fit in the in vitro testing. At six weeks in the in vivo system, the TCP stabilized specimens had an increased average resistance to tensile testing, but the increase was not significant. At six months, however, TCP-stabilized specimens exhibited a significant increase in resistance to pull-out force (p less than 0.05). Histologic examination revealed incorporation of the TCP granules in bone bridging from the endosteal cortex to the porous surfaces. TCP granules might be useful as a synthetic interposition material for stabilization of porous-coated metal components. TCP granules exhibited osteoconductive properties.