In vitro wear performance of Proplast TMJ disc implants.

This study investigates the in vitro wear performance of Proplast-Teflon Interpositional Implants (PTIPI; Vitek, Inc, Houston, TX), employing a mechanical TMJ simulator. Predictions of in vivo service life of PTIPIs are presented based on the in vitro wear testing data. Commonly employed laboratory testing methodologies are discussed in the development of alloplastic TMJ devices. Penetrative wear rates of the PTIPI at a 20-lb (9.1 kg) load were calculated to be 2.29 mm/100,000 cycles, yielding a predicted in vivo service life of PTIPIs of approximately 3 years. These results combined with reported clinical fate of this implant indicate that the intermediate- and long-term survival of this implant are uncertain.