High strength and toughness in chromatic polymer-infiltrated zirconia ceramics

ObjectiveTo evaluate the microstructure and mechanical behavior of polymer-infiltrated zirconia ceramics as a function of Fe2O3 concentration (0-0.3 mol%).MethodsPolymer-infiltrated zirconia ceramics with different concentrations of Fe2O3 were prepared by infiltration and polymerization. XRD was employed to determine phase structure. The microstructure and fracture mechanism was observed by SEM. Flexural strength and fracture toughness were measured by three-point bending method and single-edge-notched beam method, respectively. Data were analyzed by Weibull distribution. A nanoindentation system was employed to determine elastic modulus and hardness.ResultsWith increasing content of Fe2O3, the flexural strength, fracture toughness, elastic modulus and hardness are all greatly enhanced and the chromatic behavior also improves significantly. As a tradeoff made between strength and elastic modulus, specimen containing 0.2 mol% Fe2O3 is found to be the better one, with flexural strength and fracture toughness values being 336.8 MPa and 3.91 MPa m1/2, respectively. Moreover, it maintains a relatively low elastic modulus of 88.2 GPa and a moderate hardness of 4.8 GPa, close to those of natural enamel.SignificanceThis polymer-infiltrated zirconia ceramic material is a dental material of biomimetic chromatic and mechanical properties.