All-ceramic crowns, including glass-infiltrated alumina and spinel composites, are coming into widespread use because of their superior aesthetics and chemical inertness. This study investigates the residual stresses that are developed in these composites as a result of cooldown from the glass-infiltration temperature to room temperature due to slight mismatch in the coefficients of thermal expansion and its effect on the mechanical behavior of these composites. The residual stresses and strains were measured using neutron diffraction and compared with those estimated using a finite element model. The average residual stresses are found to be tensile in the alumina and spinel matrix and compresive in the infiltrated-glass. The presence of residual stresses can lead to lower crack initiation stresses and degrade the mechanical properties of the composites.
Citation: Journal of Dental Research
Pub Type: Journals
ceramic crowns, glass-infiltrated alumina