Hardness Tests on Dental Ceramics
Dental ceramics used as filling material or as restorative material must, in addition to health and visual considerations, satisfy requirements regarding strength, wear and durability.
Visual requirements can be custom-made by replicating the light effects of natural mineral dental enamel, including opalescence, fluorescence, and transparency through layers of color of varying intensity.
Strength properties can, for example, be verified by means of hardness testing. Due to limited reflectivity, the optical hardness testing method to Vickers can only be employed to a limited degree. However the instrumented indentation test, based on measurement of indentation depth, has proven very effective.
Other mechanical characteristics, in addition to hardness, can be derived from the entire test sequence, for example allowing creep or relaxation of the dental material to be measured.