Evaluation Methods of Bone Graft Materials

Abstract

Bone graft substitute materials play an important role in oral rehabilitation and understanding the biological effects of these materials is important for an optimum use. Many bone graft substitutes have been approved for clinical use but this large variability make it hard to select a graft materials. The present study aimed to evaluate the methods that we can today use to assess the degree of osseointegration of the synthetic bone augmentation materials.For this study we made three study groups, each of them consisting of six laboratory rats. On the maxilla of this animals 3-mm diameter experimental cavities were carried out. For the first study group the cavities were augmented with the collagen fleece Alveoprotect, for the second group with the synthetic bone graft Ossceram nano, and in the third group the experimental cavities were left unaugmented. The obtained samples were subjected to three examination methods: clinical and radiological examination, Optical Coherence Tomography (OCT), and a histological study.The evaluation methods of bone graft materials may be divided in two categories: in vivo and in vitro methods. In vivo methods include clinical evaluation and imagistic such as radiological or computer tomography (CT) evaluation. Even a minimal but careful direct clinical observation allows observing the appearance of the bone defect healing at its different stages. CBCT scan is the imaging method of choice in the graft materials repairment of the osseous defects because provides 3D volumetric measurements of newly formed hard tissues.Optical Coherence Tomography (OCT) is a constantly growing imaging method characterized by high spatial resolution and noninvasive subsurface detection. The OCT allowed us to evaluate the surface and subsurface of the ongoing healing bone defects in a non-destructive manner.For the in vitro methods histological methods represents the classical evaluation of the bone graft materials biological integration. On the histological samples we generally noticed the experimental defects filling with connective tissuewith various bone ingrowths from the surrounding bone tissue.However new emerging methods give new opportunities to a more accurate research of this materials. The microcomputed tomography analysis may determine the relationships and differences in three-dimensional bone mineral density and microtrabecular structures between bone grafts and their adjacent native boneTo design and produce an efficient bone graft, the researchers and clinicians should have sufficient knowledge of the characteristics of grafts such as osteogenesis, osteoinductivity, and osteoconductivity, and their other advantages and disadvantages.