Recently, an increasing amount of research has focused on the biological and mechanical behavior of highly porous structures of metallic biomaterials, as implant materials for dental implants. Particularly, pure titanium and its alloys are typically used due to their outstanding mechanical and biological properties. However, these materials have high stiffness (Young’s modulus) in comparison to that of the host bone, which necessitates careful implant design to ensure appropriate distribution of stresses to the adjoining bone, to avoid stress-shielding or overloading, both of which lead to bone resorption. Additionally, many coating and roughening techniques are used to improve cell and bone-bonding to the implant surface. To date, several studies have revealed that porous geometry may be a promising alternative to bulk structures for dental implant applications. This review aims to summarize the evidence in the literature for the importance of porosity in the integration of dental implants with bone tissue and the different fabrication methods currently being investigated. In particular, additive manufacturing shows promise as a technique to control pore size and shape for optimum biological properties.
23 January 2018 in Journal of Biomedical Materials Research Part A
Bone healing remains a critical clinical orthopedic problem. Bone, which is a greatly vascularized tissue, depends on the tight temporal and spatial link between blood vessels and bone cells. Thus, angiogenesis is crucial for skeletal growth and bone fracture healing. The purpose of this study was to evaluate the efficacy of the local application of osteogenic and angiogenic factors such as bone morphogenetic protein 9 (BMP9) and angiopoietin 1 (Ang1), respectively, and their combination as an osteoinducer in the process of bone healing. Forty-eight male albino rats, weighing 300-400 g and aged 6-8 months, were utilized in this study. The animals underwent surgery on the medial side of the tibia bone. In the control group, an absorbable hemostatic sponge was locally applied to the bone defect, while experimental groups were separated into three groups. In Group I, 1 mg BMP9 was locally applied, Group II was treated with 1 mg Ang1, and Group III was treated with local application of a combination (0.5 mg BMP9 and 0.5 mg Ang1). All experimental groups were fixed with an absorbable hemostatic sponge. The rats were sacrificed on days 14 and 28 after surgery. Local application of BMP9 alone, Ang1 alone, and their combination to a tibia defect caused osteoid tissue formation and significantly increased the number of bone cells. A gradual decrease in the number of trabecular bone, an increase in trabecular area, and no significant difference in the bone marrow area were noted. The combination of BMP9 and Ang1 has therapeutic potential in promoting the healing process of bone defects. Osteogenesis and angiogenesis are regulated by BMP9 and Ang1. These factors act together to accelerate bone regeneration more efficiently than either factor alone.