Validierung der Beständigkeit von ZrO2‐Minikugeln gegenüber Heißdampfsterilisation

Validation of the Resistance of ZrO₂‐Mini Balls against Hot Vapour Sterilisation Mini‐balls are used in bearings of dental drills. As the bearings as well as the drills are hot vapour sterilised, the bearings are operated under non‐lubricated conditions. In the present study, Raman scattering experiments show that hot vapour sterilisations of Y₂O₃ stabilised ZrO₂‐Mini‐balls lead to a phase transition from tetragonal to monoclinic ZrO₂. This phase transition finally causes the failure of ZrO₂‐Mini‐balls under the tribological conditions typical for dental drills. If, however, the ZrO₂‐Mini‐balls are stabilised using CeO₂, such hot vapour sterilisation induced phase transitions could not be observed. Subsequent tribological experiments prove that CeO₂ stabilised ZrO₂‐Mini‐balls, produced in a Sol‐Gel process, are resistant to slip‐rolling conditions, if large pores can be avoided.