Glass ceramic restorations are wide used in dental practice due to their advantages as life-like appearance, excellent biocompatibility, chemical inertness, close abrasion resistance to enamel, but their most common mechanical complications are chipping and catastrophic fracture. The purpose of the study was to evaluate monolithic ceramic posterior crowns with anatomical design, achieved by hot-pressed glass ceramics, without fdler Cergo (Degudent) and leucite reinforced Vita PM9 (Vita) by experimental analyses, in order to study their fracture behavior under compressive load. The modes of fracture will be correlated with the type of material, fracture load and displacement magnitude. For the experiments complete crown preparation were made on a first upper molar. The specimens were subjected to failure testing. Digital images of the fractured crowns fragments were used to verify the pieces in all situations. The failure occurred by cracks, splitting into two or more parts, with or without fracture of the die. The correlation of the displacement depending on the load highlights the peaks, which can be correlated with cracks produced in time. Within the limitations of this study, the tested hot-pressed monolithic ceramic crowns show similar fracture strength and fracture behavior.
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