[Aluminum oxide ceramic PORP and TORP prostheses].

The tolerance of bio-inert aluminium oxide ceramic as a PORP or TORP design has been studied histologically and clinically. Thirty-five patients had an aluminium oxide prosthesis implanted into the middle ear. There was a hearing gain of 21 dB in the speech frequencies. Patients were monitored for an average period of 20 months (3/4-2 1/4 years); the shortest period was 9 months, the longest 27. The functional results were satisfactory. The acoustic efficiency between 0-20 dB air-bone gap was not greater than with human ossicles or cartilage, although there was no fixation or resorption and a better structural stability.