Evaluation of the osteoconductive properties of scaffold containing platete-enriched-fibrin (PRF) with three calcium phosphate (TCP) in the alveolar socket repair after tooth extraction: An animal study

Bone regeneration can be accomplished through osteogenesis, osteoinduction, and osteoconduction mechanisms. This study aimed to investigate the properties of the PRF scaffold with tricalcium phosphate nanoparticles in socket preservation in an animal model. Fabrication of PRF performed. In this experimental study, 18 rats were divided into three negative control, PRF, and PRF/TCP groups. The mechanical and chemical tests including swelling rate, degradation time, and MTT tests were applied to the scaffolds. In each animal, the first maxillary right molar was extracted, and extraction sites of test groups were filled with a resorbable biocompatible biomaterial in situ hardening bone substitute. After 2 and 4 weeks all animals were sacrificed and examined histopathologically and with qRT-PCR. Histological results showed TCP in combination with PRF accelerates bone regeneration with the highest amount of lamellar bone and collagen formation compared to the control and PRF alone. Mechanical and chemical tests on the scaffolds showed the addition of TCP to the PRF scaffold decreases the swelling rate and increases the degradation time. qRT-PCR showed expression of osteogenic genes increased significantly (p < 0.05) in PRF/TCP and PRF, respectively. In conclusion, the gelatin hydrogel containing PRF/TCP scaffold led to more bone formation after tooth extraction. Therefore, the injectable PRF\TCP hydrogel is a promising candidate for bone repair and regeneration.

An Overview of Bone Replacement Materials – Biological Mechanisms and Translational Research

Bone defects might develop as a result of various pathological entities. Bone grafting is a widely used procedure that involves replacement of the missing tissue with natural or artificial substitute. The idea for artificial replacement of the missing bone tissue has been known for centuries and the evidence for these treatments has been found ever since prehistoric period. Bone grafting has been practiced for centuries with various non-osseous natural materials. The skeletal system plays a crucial role in the structural support, body movement and physical protection of the inner organs. Regeneration of bone defects is crucial for reestablishing of the form and function of the skeletal system,. While most bone defects can heal spontaneously under suitable conditions, bone grafts or substitute biomaterials are commonly used therapeutic strategies for reconstruction of large bone segments or moderate bone defect. An ideal bone grafting material should provide mechanical strength, be both osteoinductive and osteoconductive and should provide space for vascularization. In order to overcome limitations associated with the standard treatment of bone grafts, there is an increasing interest in studying substitute biomaterials, made of naturally derived or synthetic materials. Bone substitutes can be derived from biological products or from synthetic materials. Prior to testing in human subjects, the bone substitute materials should be tested in vitro and in vivo using animal models. Establishing of a suitable animal model is an essential step in the investigation and evaluation of the bone graft materials.