eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2017-03-25 10 1 51 58 10.13005/bpj/1080 13998 article Fariborz Vafaee 1 Farnaz Firooz 1 Bijan Heidari 1 Masoumeh khoshhal 2 Farnoush Fotovat 2 Hanif Allahbakhshi 2 Department of Prosthodontics, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. Department of Prosthodontics, Faculty of Dentistry, Kashan University of Medical Sciences, Kashan, Iran. The aim of this study was to compare flexural strength and fatigue resistance of 2 nanoceramic composite resin CAD/CAM blocks and a glass ceramic material. In this experimental study, resin nanoceramic blocks, Lava Ultimate, Vita Enamic and a lithium disilicate glass ceramic, IPS e.max CAD prepared on the basis of ISO 6872:2008. For 3 point bending test, 30 rectangular specimens prepared and loaded on a 10 mm span with crosshead speed of 1 mm/min. In fatigue resistance test, full crowns for mandibular second premolar were prepared for chewing cycle dynamic loading (250000cycles, 2 Hz, 100 N). Specimens survived from fatigue cycles, were loaded to fracture with a cross head speed of 1 mm/min. Failures in terms of fracture, crack formation and chipping were macroscopically recorded. The results were analyzed with one way ANOVA followed by multiple comparison Tukey HSD test. Also we used Chi Square for quantitative comparison after fracture of the specimens.The mean flexural strength was 139.921.2MPa for Lava Ultimate, 273.856.03MPa for IPS e.max CAD and 127.711.9 MPa for Vita Enamic. Significant differences were found between the groups (P<0.001).Mean fracture load after static loading was 1009.392.1 N for Lava Ultimate, 1698.5237.5 N for IPS e.max CAD and 733.2261.5 for Vita Enamic,which showed significant differences between the groups (p<0/001). Regarding to the macroscopically results after fracture load, there were no significant differences between the groups (p>0/05).The application of these nanoceramic resin composite materials for tooth-implant supported crowns seems promising. https://biomedpharmajournal.org/vol10no1/a-comparative-study-of-flexural-strength-and-fatigue-resistance-of-2-nanoceramic-composite-resin-cadcam-blocks-lava-ultimate-and-vita-enamic-and-a-lithium-disilicate-glass-ceramic-ips-e-max-cad/ Ceramics Computer-Aided Design Fatigue  Composite resins