Critical loads and standard deviations for onset of contact damage under single-cycle loading in various dental ceramics, including: Dicor, glass, porcelain (Mark II), zirconia (Y-TZP), glass infiltrated alumina (Inceram alumina, A-Infi), Empress I (EI), Empress II (EII), glass infiltrated zirconia (Inceram zirconia, Z-Infi), and alumina. The composition, manufacturer, and material properties of these dental ceramics and glass are summarized in Table 1. Note: O, outer cone cracks; Y, yield.