The active lives of the urban people, increasing traffic accidents, and extended lifespan lead to various defects in the body, such as fractures and non-functioning organs. Use of different materials available in the environment to treat the damages is not new; they were applied even in the old ages. Today, with the developments in science and engineering, it became possible to manufacture devices in our laboratories that are fully biocompatible and able to substitute for damaged organs and tissues in performing their functions quite satisfactorily. In general, novel metal and ceramic products are used in the treatment of damaged hard tissues such as hip prostheses or dental implants. Polymers are mostly used in softer tissues and organs or in modern tissue engineering applications as scaffolds or in the delivery of bioactive agents. Hydrogels, which can hold large amounts of water and mimic the extracellular matrix of the tissues, can be successfully used in 3D bioprinting biomaterials carrying cells. Today, studies are intensely focused on the production of various tissues such as bone, cartilage, nerve, skin, etc., are tools of the new field of research called “Tissue Engineering” and are used in what we now call “Regenerative Medicine.”