Polymers offer a wide range of choices for medical applications because of their versatility in properties and processing. This article provides an overview of polymeric materials and the characteristics that make them a unique class of materials. It describes the ways to classify polymers, including the polymerization method, how the material deforms, or molecular origin or stability. The article contains tables that list common medical polymers used in medical devices. It describes the medical polymer selection criteria and regulatory aspects of materials selection failure analysis and prevention. Failure analysis and prevention processes to determine the root cause of failures that arise at different stages of the product life cycle are reviewed. The article describes the mechanisms of plastic product failure analysis. It discusses the trends in the use of medical polymers, such as high-performance polymers for implants, tissue engineering, and bioresorbable polymers.

This article discusses the several aspects of biocompatibility of polymers, including selection of a suitable polymer, specific use of a material, contact of polymer on body site, and duration of the contact. It describes factors influencing the biological response to the polymer in a biocompatibility perspective. These include raw materials, manufacturing process, cleaning and sterilization, and biodegradation and biostability. The article reviews the general testing of polymer, such as chemical, mechanical and thermal tests, to ensure that the polymer is stable and has not been adversely altered due to sterilization or processing. It concludes with a description of the guidance, provided by the regulatory authorities, on the biocompatibility testing of polymers and polymer-containing devices that can aid in selecting the right analysis.

Ceramics are used widely in a number of different clinical applications in the human body. This article provides a brief history of the bioceramics field and information on the classification of the different types of bioceramics. These include bioinert ceramics, bioactive ceramics, and bioresorbable ceramics. The article describes the third-generation bioceramics, classified by Hench and Polak, such as silicate-substituted hydroxyapatite and bone morphogenic protein-carrying calcium phosphate coatings. It reviews several examination methods that are used to test the biocompatibility of ceramics, namely, biosafety testing, biofunctionality testing, bioactivity testing, and bioresorbability testing.

This article tabulates materials that are known to have been used in orthopaedic and/or cardiovascular medical devices. The materials are grouped as metals, ceramics and glasses, and synthetic polymers in order. These tables were compiled from the Medical Materials Database which is a product of ASM International and Granta Design available by license online and as an in-house version. The material usage was gleaned from over 24,000 U.S. Food and Drug Administration (USFDA), Center for Devices and Radiological Health, Premarket notifications (510k), and USFDA Premarket Approvals, and other device records that are a part of this database. The database includes other material categories as well. The usage of materials in predicate devices is an efficient tool in the material selection process aiming for regulatory approval.

The biocompatibility of a material relates to its immunological response, toxicity profile, and ability to integrate with surrounding tissue without undesirable local or systemic effects on a patient. This article underscores the transformation of the medical device design ecosystem engaged as an integral part of the device ecosystem. It discusses the various applications of biomaterials, including orthopedic, cardiovascular, ophthalmic, and dental applications. The article describes the four major categories of biomaterials, such as metals, polymers, glass and ceramics, and composites. A discussion on natural materials, nanomaterials, and stem cells is also provided. The article concludes with information on examples of biomaterials applications, including endovascular devices, knee implants, and neurostimulation.

This article outlines some of the selection criteria for choosing an implant material for biomedical devices in orthopedic, dental, soft-tissue, and cardiovascular applications. It details the development of implants based on materials, such as metallic implants, ceramic implants, and polymeric implants. The article discusses the specific problems associated with implant manufacturing processes and the consequent compromises in properties of functionally graded implants. It describes the manufacturing of the functionally-graded hip implant by using the LENS process. It reviews the four different types of tissue responses to the biomaterial. The article discusses the testing of implant failure, such as in vitro and in vivo assessment of tissue compatibility.