Comparison of three block bone substitutes for bone regeneration: long-term observation in the beagle dog

Abstract

This study aimed to evaluate the impact of three types of block bone substitute material on bone formation and graft resorption in vivo. Standardized bone defects (n = 4 defects/animal) were created in the calvaria of nine dogs. Block bone substitutes made of deproteinized bovine bone mineral (DBBM), beta-tricalcium phosphate (β-TCP) and a mixture alpha-TCP and hydroxyapatite (α-TCP/HA) were inserted into the bone defects. A fourth defect was left untreated (empty). All sites were covered with a collagenous membrane. Block biopsies were harvested at 3, 6 and 12 months post-implantation and analyzed by micro-CT and histology. Biomaterial absorption was minimal and incorporation within the defect margin was good for all biomaterials. However, β-TCP demonstrated a relatively greater volume of new bone formation and less residual material volume when compared with DBBM and α-TCP/HA. Conversely, α-TCP/HA showed higher osteoconductive potential and a greater new bone area compared with the other two biomaterials. The block bone substitutes used in the present in vivo study showed advantageous in terms of maintenance of their original form in bony defect. However, the positive impact of all biomaterials on new bone formation and replacement of bone was minor even at 12 months. These findings indicate that block bone substitutes are not well suited to vertical bone augmentation. Further investigations are required to improve the insufficient new bone volume for promising clinical results.

Demineralized bone matrix and calcium-phosphate cement in bone regeneration in rats

“…A demineralized bone matrix has been shown to be inert from the immunologic point of view, stimulates osteogenesis, is incorporated into the body and replaced with new bone from the hostage 6,7 . In this study, the matrix proved to be biocompatible, because even though there was an inflammatory reaction and the presence of giant cells at 4 weeks of evaluation, at 8 weeks this reaction was mild and there were no giant cells at all.…”

“…The reason for this impaired defect healing seems to be related to the fast ingrowth of soft tissue, thus blocking bone formation at the edges of the defect and thereby preventing bone healing 4 . Currently, autogenous bone grafts are the preferred material for craniofacial reconstruction 5,6 . Despite being highly effective, there are several problems associated with their use.…”

“…Recently, to minimize these problems, interest has been shown in the use of allogenic and alloplastic bone substitutes. The ideal graft should be osteoinductive to stimulate osteogenesis and osteoconductive to provide a scaffold for establishing optimal conditions for ingrowth of blood vessels and cells with osteogenic potential 5,6,8 . The demineralized allograft may be used as a matrix, especially since it is immunologically harmless, stimulates osteogenesis and is incorporated into the new bone formed 6 .…”

“…The ideal graft should be osteoinductive to stimulate osteogenesis and osteoconductive to provide a scaffold for establishing optimal conditions for ingrowth of blood vessels and cells with osteogenic potential 5,6,8 . The demineralized allograft may be used as a matrix, especially since it is immunologically harmless, stimulates osteogenesis and is incorporated into the new bone formed 6 . Calcium phosphate cement has been used as a bone substitute for reconstruction of bone loss 8 .…”

In vitro and in vivo biocompatibility of calcium‐phosphate scaffolds three‐dimensional printed by stereolithography for bone regeneration

“…As an alternative, different types of blocks scaffolds made of bovine hydroxyapatite (HA), allograft, or synthetic CaP were suggested; however, most of them require to be shaped by hand, at the dimensions of the defect, which may be challenging in a daily practice (Carrel, Wiskott, Scherrer, & Durual, 2016;Giuliani et al, 2016;Sawada et al, 2018). In case of non-containing or large defects, these granulated biomaterials lack in three-dimensional (3D) stability and require a titanium reinforced membrane or autogenous bone plates in order to hold up the regeneration chamber.…”