Handbook of Materials for Medical Devices

Preface

In January 2000, the National Institutes of Health (NIH) estimated that 8 to 10% of Americans, roughly 20 to 25 million people, had some type of medical device implanted in their bodies. This information was presented at the NIH Technology Assessment Conference on Implants, held from January 10-12, 2000, in Bethesda, MD. In the United States alone, the market for orthopedic implants, including total knee and hip replacements, spinal implants, and bone fixation devices, surpasses two billion dollars annually. Globally, this market exceeds $4.3 billion each year. These figures underscore the significant economic impact of the medical device industry, a trend that is expected to continue growing due to advancements in medical and materials science and the aging population, particularly in the United States where some baby boomers are now in their sixties.

For thousands of years, humans have endeavored to restore function to bodies afflicted by trauma or disease. Ancient civilizations such as the Phoenicians, Etruscans, Greeks, Romans, Chinese, and Aztecs utilized gold in dentistry as early as 2700 BC. The Egyptians used linen sutures around 2000 BC. However, it is only in the past century that man-made materials and devices have been sufficiently developed to be extensively used in replacing parts of the human body. These specialized materials, capable of functioning in close contact with living tissue with minimal adverse reactions or rejection by the body, are known as biomaterials. Today, biomaterials are integral in replacing or enhancing the function of every major body system (skeletal, circulatory, nervous, etc.). Common implants include the aforementioned orthopedic devices; cardiac implants such as artificial heart valves and pacemakers; soft tissue implants such as breast implants and injectable collagen for soft tissue augmentation; and dental implants for replacing teeth/root systems and bony tissue in the oral cavity.

Recognizing the increasing significance of biomaterials and bioengineering, ASM International has published numerous reviews over the past 20 years, documenting the properties and failure mechanisms of metallic implant materials. Most of these reviews are available in various volumes of the Metals/ASM Handbook series. Until now, however, there has not been a single, definitive source published by ASM that encompasses the many crucial topics associated with the use of various implant materials, including metals, ceramics, polymers, composites, and coatings. These topics include:

• Implant material selection and applications
• The body/oral environment and its impact on implant material performance
• Basic concepts of biocompatibility
• Tissue attachment mechanisms
• Biophysical and biomechanical requirements of implant materials
• Corrosion and wear behavior, including the degradation of polymeric materials