Disadvantages Of Biomaterials

Moreover in general, the biomaterials can be further categorized into: polymers, metals, ceramics, and composites.

1. Polymers: A great variety of polymers are used as biomaterials in medicine. Their applications vary from facial prostheses to tracheal tubes, from dentures to hip and knee joints and from kidney and liver parts to heart components. Polymeric materials are also used for medical adhesives and sealants and are also used for coatings that perform a range of functions.

2. Metals: As a choice of materials, metals are most commonly used for load-bearing implants. For example, in some of the most common orthopedic surgeries implantation of metallic implants is involved. They vary from simple wires and screws to fracture fixation plates and total joint prostheses (artificial hip joints) for knees, hips, shoulders, ankles, spines, etc. In addition to orthopedics, metallic implants are also used in maxillofacial surgery, cardiovascular surgery, and in dental surgery [Davis, J.R.. Overview of Biomaterials and Their Use in Medical Devices. : ASM International, Dec 2003].

Composites: The most successful composite biomaterials are used as healing materials or as dental cements in the field of dentistry. Though carbon-hydrogen and carbon- carbon strengthened polymer composites are of greater interest for repairing bone and for replacement of joints because of their low elastic modulus levels, but, till now these materials have not showed a combination of biological and mechanical properties suitable for these applications. However, composite materials are broadly used for prosthetic limbs, where their blend of low density/weight and high strength make them suitable materials for such applications. The two most common composites are BIS-GMA-quartz-silica filler and PMMA glass filler. [ D. Williams, An Introduction to Medical and Dental Materials, Concise Encyclopedia of Medical and Dental Materials, D. Williams, Ed., Pergamon Press and The MIT Press, 1990,