Macro-porous calcium phosphate scaffold with collagen and growth factors for periodontal bone regeneration in dogs

The periodontal bone regeneration has always been considered as a major challenge in maxillofacial clinic. Unfortunately, current treatments cannot achieve optimal therapeutic effect. Self-setting calcium phosphate bone cement (CPC) is regarded as promising material to solve periodontal problem due to its good biocompatibility, mineral similarity to the natural bone’s composition. Moreover, it can be arbitrarily shaped, form bio-resorbable hydroxyapatite (HA) in situ to fill complex periodontal bone cavities perfectly. So far, there are lots of related in-vitro investigations; however, in-vivo experiments which could precisely show the real effects of CPC’s internal performances are rarely reported. Therefore, in this study, CPC were implanted into bilateral mandible defect of 8 beagles to evaluate its degradation ability and osteogenesis through Micro-CT scan and histological morphology analysis at determined time. Because of the intrinsic drawbacks of raw CPC, reinforced ingredients including collagen and growth factors were selected to synthesis different modified-CPC systems. The results illustrated that the samples’ degradation ability could be largely increased by nearly 60% with the help of macro-porous structure and collagen. In addition, by using the same ingredients, the osteogenisis of those samples could be promoted by 12%. What’s more, growth factors were proved to be the most important factor to increase the CPC’s new bone formation ability (22% more new bone could be obtained after using growth factors after 6 months implantation). The data obtained from histological analysis has presented the similar changing trend. Overall, these results illustrated macro-porous structure; collagen and growth factors could both effectively promote the CPC’s degradation ability and osteogenesis in vivo, which suggested the macro-porous CPC with collagen and growth factors would be promising as bioactive materials for periodontal bone tissue regeneration.