Aluminium release as a new factor in the estimation of alumina bioceramic implants

Aluminium release from an alumina bioceramic was investigated parallel to standardized biocompatibility testing in an animal experiment. Alumina implants were introduced into both femurs of male rats and into the mandible of male guinea-pigs. After a period of 6 or 8 months animals were sacrificed. The bone surrounding the implant was examined by utilizing standard histological procedure. The material was well tolerated both in the rat and in the guinea-pig. The surface of the removed implants was examined in the SEM. No changes were observed. In both femurs of the 10 experimental and six control rats the aluminium content was determined by utilizing the atomic absorption spectroscopy method (AAS). It was found that the level of aluminium was essentially higher in the bones of the experimental animals. Therefore the safety of alumina introduction into human organisms for a long period becomes open to doubt, in spite of the favourable results of the short-term biocompatibility tests.