caa a22 4500 388022337 CHVBK 20180307124928.0 cr unu---uuuuu 161130e199808 xx s 000 0 eng 10.1557/JMR.1998.0312 doi S0884291400045489 pii (NATIONALLICENCE)cambridge-10.1557/JMR.1998.0312 Effect of microstructure on damage tolerance in grinding dental glass-ceramics [Elektronische Daten] This study investigated the modes of grinding-induced subsurface damage in dental glass-ceramics and the influence of microstructure on strength degradation. A series of micaceous glass-ceramics crystallized from the same glass composition were tested. The diameter of the mica platelets in these glass-ceramics was varied via heat treatment. Grinding was performed using three diamond wheels (with diamond particle size of 40, 100, and 180 µm, respectively) at depth of cut ranging from 5 µm to 100 µm. A bonded- interface technique was employed to examine the machining- induced subsurface damage. Relatively large median and lateral cracks were found in the glass-ceramic with the smallest mica platelets. In contrast, no cracks were found in the material containing large mica platelets. The ground specimens were fractured in four-point flexure to measure strength as a function of grinding conditions and mica platelet sizes. The strength of the ground specimens was reduced to approximately 30% of the strength of the polished specimens for the glass- ceramic containing the smallest mica platelets; that of the glass-ceramic with the intermediate mica platelet size was reduced to 60%. In contrast, virtually no strength loss occurred with the glass-ceramic containing large mica platelets. Microstructure was shown to determine the mode and degree of strength-controlling damage in the machining of these dental glass-ceramics. Polishing after grinding removes subsurface damage and recovers strength for the glass-ceramics containing fine mica crystals. Copyright © Materials Research Society 1998 Xu Hockin H. K. Paffenbarger Research Center, American Dental Association Health Foundation, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 Jahanmir Said Ceramics Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 Journal of Materials Research Cambridge University Press 13/8(1998-08), 2231-2236 0884-2914 13:8<2231 1998 13 JMR https://doi.org/10.1557/JMR.1998.0312 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1557/JMR.1998.0312 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Xu Hockin H. K. Paffenbarger Research Center, American Dental Association Health Foundation, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 NATIONALLICENCE 700 1- Jahanmir Said Ceramics Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 NATIONALLICENCE 773 0- Journal of Materials Research Cambridge University Press 13/8(1998-08), 2231-2236 0884-2914 13:8<2231 1998 13 JMR CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge