VESTAKEEP® PEEK—Special Grades with High Biocompatibility

With its combination of properties paired with excellent resistance to conventional cleaning and sterilization processes, VESTAKEEP^® PEEK opens up new options for the medical sector. For this market, Evonik offers special grades designated by an M or an I.

As a rule, PEEK is added to medical products to achieve greater benefit: to save weight, enable greater freedom of design and higher functional integration, but also as a less expensive alternative to stainless steel or other materials.

The following are characteristic features of VESTAKEEP^® PEEK for medical applications:

• Because of its biocompatibility, PEEK is suitable for many medical applications. Please bear in mind the relevant approvals.
• Its high chemical resistance toward conventional cleaning agents, among others, enables wide-ranging use.
• VESTAKEEP^® PEEK is also highly suitable for reusable medical products due to its excellent resistance to sterilization by superheated steam. The handles of operating instruments are one example. As compared with the other plastics used today, our high-performance polymer offers better sterilizability and therefore a longer service life. Since it can easily be colored, it allows color coding.
• The high-temperature polymer shows good resistance to high-energy radiation such as gamma or X-rays.
• Good X-ray transparency makes it interesting for use in operating rooms. VESTAKEEP^® PEEK prevents artifacts on the X-ray picture when using fixatives.
• Since VESTAKEEP^® PEEK offers high mechanical strength, wear resistance and impact strength, a further interesting field of application is sports for persons with disabilities, where the high-performance polymer is used in prostheses.
• The good dimensional stability enables its use for high-precision components. Added to this is its good electrical insulation. This combination is often particularly important for medical devices, as shown by the battery-powered screwdriver in orthopedic surgery.
• Finally, VESTAKEEP^® PEEK shows good resistance to hydrolysis toward water, solvents and chemicals.

Although VESTAKEEP^® PEEK has been used only relatively recently in the medical sector, the material's extensive property profile opens up a series of interesting possible applications such as surgical instruments, endoscopes, applications in in-vitro diagnostics, orthopedic surgery, the spinal and dental fields, as well as in analytical devices and metering of medicines.

PEEK polymers have been used in implant applications since the mid-1980s. Since 1999, PEEK has been the most important thermoplastic substitute for titanium implants. One of its advantages over titanium is its high elasticity, which is of the same order as that of bone. This prevents the stress-shielding effect: In contact with the bone, the latter is not entirely shielded from mechanical stress and can therefore retain its strength for many years.