Sintered feldspathic and leucite reinforced ceramic are used for the fabrication of metal-free restorations

New ceramic materials, like hot-pressed glass ceramics can be used to achieve monolithic full anatomic all-ceramic dental restorations even in the molar areas. Due to the fact that these materials are brittle and susceptible to fracture, the aim of the study was to reveal the fracture behaviour of hot-pressed glass ceramic molar crowns under different loading methods. For the experimental analyses anatomically first upper molar crowns were fabricated. The specimens were submitted to cyclic fatigue loading and fracture resistance testing. The mode of failure depends on the loading mode. Static loading, wide used in literature, can give an information regarding the values of fracture resistance, but are not illustrative for the long-term success of the restorations, like fatigue behaviour. The most accurate way to simulate the clinical behaviour is the cyclic loading in order to simulate a defined period of oral service. In vitro testing is important before the clinical application. Keywords— fracture, hot-pressed ceramics, loading modes, molar crowns.