In the field of oral medicine, dental implant surgery has become an important means of restoring missing teeth. However, the success of implants largely depends on the patient’s bone quality. For patients with poor bone quality, bone grafting surgery becomes a crucial step in improving the success rate of implants. So, where do the bone graft materials used in dental implants come from? Below, we will provide a detailed introduction from multiple perspectives.
Where Does Cadaver Bone for Dental Implants Come From?
Autogenous Bone
Autogenous bone, as the name suggests, refers to bone tissue derived from the patient’s own body. It is an ideal bone graft material in dental implants because autogenous bone matches the human tissue structure, mechanical properties, and biological characteristics, possessing excellent bone regeneration ability and anti-infective capacity. Autogenous bone can be taken from positions such as the mandibular chin, maxillary tuberosity, and mandibular ramus within the patient’s oral cavity, or collected from exposed bone tissue in the surgical field during the operation. Additionally, the main extracranial bone source is the ilium.
Autogenous bone has good bone-forming and bone-inducing properties, containing calcitonin, sialoprotein, bone calcium protein, and bone sialoprotein, which can participate in and promote new bone maturation. At the same time, autogenous bone also contains an active microvascular system, which can accelerate the revascularization of new bone. Therefore, autogenous bone has the strongest osteogenic ability compared to other bone substitute materials, with the most stable effects.
However, autogenous bone also has some limitations. Firstly, a certain degree of bone resorption occurs after autogenous bone grafting, and it causes greater trauma to the patient. Secondly, for extensive bone defects, the amount of autogenous bone is limited, which may not meet the surgical requirements. Therefore, in dental implant surgery, autogenous bone is usually used in combination with bone substitute products to achieve better results.
Allograft Bone
Allograft bone refers to bone tissue derived from different individuals of the same species. This bone graft material has a natural bone tissue structure, good bone conductivity, and certain bone-inducing potential. Allograft bone can effectively compensate for the shortage of autogenous bone sources, thus having great clinical application prospects.
Allograft bone is usually stored in bone banks, and its sources include cadaver bones and healthy ribs removed from other individuals during surgery. There are three types of allograft bone, including fresh-frozen bone (FFB), freeze-dried bone allograft (FDBA), and demineralized freeze-dried bone allograft (DFDBA). These types of allograft bone undergo different processing techniques and have different biocompatibility and osteogenic capabilities.
For example, FDBA and DFDBA undergo processes such as defatting and demineralization to reduce immunogenicity and increase biocompatibility, while retaining growth factors such as bone morphogenetic protein, thus possessing a certain degree of bone-inducing ability. However, allograft bone loses some mechanical stability during the demineralization process, so it cannot support the filling of larger bone defects on its own. In addition, FFB carries risks of immunogenicity and disease transmission, and although its immunogenicity is significantly reduced after a series of treatments, it still needs to be used with caution.
Xenograft Bone
Xenograft bone refers to bone tissue derived from different species, mainly including mammals, coral, algae, etc. The bone tissue structure, composition, and mechanical properties of these materials are similar to human bone tissue, and their implantation into the body is conducive to the adhesion of osteogenic cells.
In dental implant surgery, commonly used xenograft bone graft materials include bone matrix derived from animals, such as deproteinized bovine bone matrix (DBBM). This material undergoes processes such as heat treatment and chemical extraction to remove organic matter while retaining inorganic components, with its chemical composition and inorganic components being very similar to human cancellous bone. New bone uses the porous structure as a scaffold, effectively promoting bone formation. DBBM has excellent bone conductivity but no bone-inducing effect. Therefore, DBBM is usually mixed with autogenous bone particles or fresh blood and implanted into the bone defect area to promote new bone generation.
In addition, bone matrix extracted from algae and coral is called bone-like matrix. Coral’s hydroxyapatite is a porous hydroxyapatite that can conduct bone cells into its porous scaffold. Although it does not have osteogenic-inducing activity on its own, it can provide a scaffold for bone tissue ingrowth for a sufficient period of time.
Synthetic Bone Materials
Synthetic bone materials refer to artificial substitutes for human bone. These materials have good biocompatibility and do not cause any inflammation or rejection reactions. Synthetic bone materials mainly include polymer synthetic materials, inorganic materials, and other types.
Polymer synthetic materials, such as polymethyl methacrylate and high-density polyethylene, have excellent physical properties and processing properties. Inorganic materials, such as tricalcium phosphate, hydroxyapatite, and alumina bioceramics, are closer to the inorganic components of human bone. Among them, hydroxyapatite (HA) is a calcium phosphate salt mainly composed of calcium and phosphorus, with a chemical composition close to the inorganic component of bone tissue. When used for bone-guided regeneration, HA has bone conductivity and is non-resorbable, which is beneficial for maintaining the stability of the bone regeneration space.
Synthetic bone materials are increasingly being used in dental implant surgery. For example, studies have shown that using hydroxyapatite powder collagen membranes as artificial bone graft materials, placing them on the elevated sinus mucosa after maxillary sinus lifting, and implanting the implant after a healing period results in the formation of a large amount of new bone around the implant with bone integration.
Conclusion
In summary, the sources of bone graft materials in dental implants are diverse, including autogenous bone, allograft bone, xenograft bone, and synthetic bone materials. Each material has its unique advantages and limitations, and the choice in clinical applications needs to be based on the patient’s specific conditions and needs. Although autogenous bone has the best osteogenic ability and biocompatibility, it is limited by bone volume and trauma issues; allograft bone and xenograft bone compensate for the shortcomings of autogenous bone to some extent but carry risks of immunogenicity and disease transmission; synthetic bone materials, with their good biocompatibility and processability, have become a research hotspot in recent years.
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