When Dentronix, a subsidiary of the Swiss Coltene/Whaledent Group, was designing a new “heat-resistant” bite bar, it needed a material that could withstand the high temperatures of a dry heat sterilizer. The company chose PEEK, a high-performance polymer used in a variety of high-end medical applications, because of its good overall performance.

Bite bars are orthodontic tools used to secure braces to teeth. The orthodontist places the braces on the patient’s teeth and then places the bite bar, which allows the metal insert to help the braces slide into the correct position when the patient bites down. Since bite bars mechanically secure braces to teeth, impact strength is important, and PEEK polymer meets the requirements for bite pressure.

A requirement for the new design was that the bite bar had to withstand multiple high-temperature sterilization cycles in a dry heat sterilizer. A dry heat sterilizer can raise the temperature in the sterilization chamber to 190°C (375°F). Inside the sterilization chamber, the temperature can reach as high as 216°C (420°F). PEEK polymer allows the bite bar to withstand at least 50 cycles of dry heat sterilization without any degradation of performance or change in shape or color. In addition to withstanding the high temperatures of the dry heat sterilizer, the bite bar must also withstand autoclave sterilization and solution sterilization (such as glutaraldehyde, peracetic acid and hydrogen peroxide). When designing the new Dentronix bite bar, the company tested a variety of materials, including polyphenylene sulfide (PPS), and found that PEEK polymer had the best overall properties for this application.