Hydroxyapatite-Based Materials: Synthesis and Characterization

The use of foreign materials to be used as implants within or outside the human body is not new. There are reports of more than 2000 years old which indicate the replacement of bone material in order to repair seriously damaged tissues. In the mid-nineteenth century it was attempted to repair human body parts using the materials available according to the technological advance of the time, unfortunately, these materials were mainly based on copper or bronze, suffering severe corrosion within the human organism's environment, and causing infections that also endangered the lives of patients. For this reason the prostheses used were basically external. Over the years (the late nineteenth and early twentieth century) were made several attempts to use different materials such as gold, glass and new alloys with better results. Advances in polymer chemistry and the development of new alloys in modern metallurgy during the second half of the twentieth century gave rise to a variety of materials for reconstruction and replacement of some tissues inside and outside the human body. In the case of ceramic materials, the development of modern technologies has led to new materials with chemical, physical and mechanical properties that make them an excellent choice for applications in dental and orthopedic implants. There are many ways to define a biomaterial, which has not been easy given the breadth of the term. In the European Society for Biomaterials Consensus Conference in 1986, was given the following definition: “Biomaterial is a material or substance, whether used alone or in making a medical device designed to interact with human tissues to monitor body functions or to treat pathological conditions of the same” (Mattox, 1992; Ravaglioli & Krajewski, 1992). A synonym for this is "biomedical material". All definitions include the word "material", which usually indicates a solid consistency substance used to manufacture an object, which may consist of living or nonliving materials. If the material is alive, then is called "graft" and those non-living, placed inside the body, are called "implants". With a more limited meaning, the so-called "prostheses" can be considered as "endoprostheses", if they are contained entirely within the body, or "exo-prosthesis"(or "external prosthesis") if they are completely out. In other hand, the "biocompatibility" of a biomaterial is defined as their ability to successfully fulfill a specific application, with an appropriate response of the host. That is, the biocompatibility means more than the fact that a material is not harmful in the body; it