“…The fabrication of dental restorations has been simulated in research laboratories for in vitro studies with standardized specimens (bars and discs) to study the quality of the material as provided by the manufacturer; to expose the specimens to conditions similar to the oral environment (low-temperature degradation 7 ) and dental laboratory (finishing, polishing, and sandblasting); and to determine the mechanical properties (failure load, 8 flexural strengths, [9][10][11][12] fracture toughness, 13 wear, 14 and fatigue). 15 Fractography of broken and/or worn specimen parts (crowns, [16][17][18][19][20][21] bars, 22,23 discs 10,11,24 ) provides a means to determine where a fracture originates, whether from flaws originating from the original manufacturing process or from dental laboratory surface treatments, thereby improving the quality control of future restorations. These flaws vary in size, shape, distribution, and orientation and are the result of bulk fabrication processes (sintering or pressing pores, 25 contaminants such as Al 2 O 3 or CaO, excessive grain growth, 2nd phase grains, and/or inclusions) or surface treatments (performed by the technician and/or dentist), such as grinding damage, sandblasting damage, milling scratches or grooves, and poor handling.…”