Preclinical and Clinical Evaluation of Collagen-Based Biomaterials for Guided Bone Regeneration

Abstract Body: Bone augmentation procedures are frequently performed in order to reestablish bone alveolar bone arquitecture when we find bone defects caused by infection, trauma or tumor. In this regard, the election technique to solve most of the defects is the use of a barrier membrane and a bone replacement graft. In the market, we have available a wide variety of membranes; however, collagen-based membranes are the most commonly used. Two techniques are employed to obtain collagen membranes: i) the first involves the extraction, purification, and polymerization of native collagen to form a functional biomaterial, and ii) the other technique involves decellularizing native tissues such as bovine or porcine small intestinal submucosa, pericardium, and dermis; these are the so-called extracellular matrix membranes (ECM). Additionally, they can also be subjected to the process of cross-linking in order to increase their degradation time resulting in slower degradation when the degree of cross-linking is increased. All these modifications and characteristics may influence the properties of the membrane, resulting in variations on the mechanical properties; degradation times; resistance to hydrolytic, enzyme or bacterial degradation; or biomineralization pattern, among others. On the other hand, biphasic collagenated bone substitutes are also gaining relevance in this area. They have shown to improve, among others, the neovascularization and cell recruitment. The use of a thermosensitive gel to ease their handling and their clinical use have also been implemented. However, the clinical performance of this bone replacement graft is still being performed.