RESIDUAL STRESS AND PHASE TRANSFORMATION IN ZIRCONIA RESTORATION CERAMICS

摘要

A ceramic based dental restoration's service life is generally limited to a few years until catastrophic fatigue cracking. Materials improvements over the last few years have helped extend performance. With patient life expectancy continuing to increase, and limits on available biocompatible material options, the need for more understanding of existing materials used in crown design continuous to grow. Future generations of multi layer ceramic restorations can benefit from the manufacture process and geometries to better control residual stress at the contact surface and internal interfaces. As an example, having compressive residual stress beneath applied external loads increases damage resistance and delays crack initiation. Measurement techniques interpreting internal stress states are in development. At different locations of the crown, residual stresses as large as ±400 MPa and tetragonal to monoclinic phase transformations on a typical zirconia-porcelain crown was measured using a laboratory micro-diffraction system.