Tissue reactions to particles of bone‐substitute materials in intraosseous and heterotopic sites in rats: discrimination of osteoinduction, osteocompatibility, and inflammation

Abstract

Two rat models were used to characterize tissue-specific reactions to particles of bone-substitute materials: one for osteocompatibility in a healing tibial wound and the other in a heterotopic, subcutaneous site. Small, unicortical tibial wounds in rats healed spontaneously, beginning with the rapid proliferation of intramedullary woven bone. That temporary bone was resorbed by osteoclasts and finally, the cortical wound was healed with lamcllar bone and the medullary space was repopulated with marrow. When various particulate materials were implanted into fresh wounds, three types of reactions were observed. (1) Demineralized bone powder (DBP) and non-resorbable calcium phosphate (nrCP) were incorporated into the reactive medullary and cortical bone.(2) Polymethylmethacrylate (PMMA) particles were surrounded with a fibrous layer, but did not impair bone healing. (3) Polyethylene (PE) shards and resorbable calcium phosphates (rCPs) were inflammatory and inhibited osseous repair.Subcutaneous sites showed osteoinductive, fibrotic, or inflammatory responses to these materials. Only DBP induced endochondral osteogenesis subcutaneously. The nrCP evoked a fibrous reaction. In contrast, rCPs, PMMA, and PE shards generated inflammatory reactions with each particle being surrounded by fibrous tissue and large multinucleated giant cells.In conclusion, only DBP showed osteoinductive as well as osteocompatible properties. The nrCP was osteocompatible. The rCPs stimulated various degrees of inflammatory responses. PMMA was osteocompatible and did not interfere with the bone healing process. PE was not osteocompatible and generated foreign body reactions in both sites. Use of the two sites distinguishes osteoinductive, osteocompatible, and inflammatory properties of particles of bonc-substitute materials. 0

The effect of Emdogain® and platelet-derived growth factor on the osteoinductive potential of hydroxyapatite tricalcium phosphate

“…In the present study, specimens from all three experimental groups failed to demonstrate the presence of osteoinduction, and this is in agreement with a number of other studies which reported a lack of osteoinduction following implantation of HA-TCP into experimental animals [23,27,28].…”

Effect of coating Straumann® Bone Ceramic with Emdogain on mesenchymal stromal cell hard tissue formation

“…Although the uncoated Straumann® Bone Ceramic material was not osteoconductive, another HA/TCP preparation, Zimmer, demonstrated an osteoconductive capacity similar to previously described [17]. Similar findings of heterogeneity amongst HA-TCP preparations have been reported [55,56].…”

Results of high tibial osteotomy: review of the literature

“…Bone graft is generally considered to be the most successful bone filling material because of its osteoconductive, osteoinductive and osteogenic properties [14,21,23,31,41]. Nevertheless, autograft harvesting involves increased operative time and the donor site morbidity, while allograft has lower osteoinductive properties and carries disease transmission risk.…”