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@Article{RamosCaLaMaBoCeMe:2016:MiChSC,
               author = "Ramos, Nath{\'a}lia de Carvalho and Campos, Tiago Moreira Bastos 
                         and La Paz, Igor Siqueira de and Machado, Jo{\~a}o Paulo Barros 
                         and Bottino, Marco Antonio and Cesar, Paulo Francisco and Melo, 
                         Renata Marques de",
          affiliation = "{Universidade Estadual Paulista (UNESP)} and {Instituto 
                         Tecnol{\'o}gico de Aeron{\'a}utica (ITA)} and {Universidade 
                         Estadual Paulista (UNESP)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)} and {Universidade Estadual Paulista (UNESP)} and 
                         {Universidade de S{\~a}o Paulo (USP)} and {Universidade Estadual 
                         Paulista (UNESP)}",
                title = "Microstructure characterization and SCG of newly engineered dental 
                         ceramics",
              journal = "Dental Materials",
                 year = "2016",
               volume = "32",
               number = "7",
                pages = "870--878",
                month = "July",
             keywords = "Ceramics, Dental porcelain, Glass ceramics, Subcritical crack 
                         growth, Stress corrosion, Computer-aided design, Flexural 
                         strength, Young's modulus, Spectroscopy.",
             abstract = "Objectives. The aim of this study was to characterize the 
                         microstructure of four dental CAD-CAM ceramics and evaluate their 
                         susceptibility to stress corrosion. Methods. SEM and EDS were 
                         performed for microstructural characterization. For evaluation of 
                         the pattern of crystallization of the ceramics and the molecular 
                         composition, XRD and FTIR, respectively, were used. Elastic 
                         modulus, Poisson's ratio, density and fracture toughness were also 
                         measured. The specimens were subjected to biaxial flexure under 
                         five stress rates (0.006, 0.06, 0.6, 6 and 60 MPa/s) to determine 
                         the subcritical crack growth parameters (n and D). Twenty-five 
                         specimens were further tested in mineral oil for determination of 
                         Weibull parameters. Two hundred forty ceramic discs (12 mm 
                         diameter and 1.2 mm thick) were made from four ceramics: 
                         feldspathic ceramic FEL (Vita Mark II, Vita Zahnfabrik), 
                         ceramic-infiltrated polymer PIC (Vita Enamic, Vita Zahnfabrik), 
                         lithium disilicate LD (IPS e.max CAD, Ivoclar Vivadent) and 
                         zirconia-reinforced lithium silicate LS (Vita Suprinity, Vita 
                         Zahnfabrik). Results. PIC discs presented organic and inorganic 
                         phases (n = 29.1 +/- 7.7) and Weibull modulus (m) of 8.96. The FEL 
                         discs showed n = 36.6 +/- 6.8 and m = 8.02. The LD discs showed a 
                         structure with needle-like disilicate grains in a glassy matrix 
                         and had the lowest value of n (8.4 +/- 0.8) and m = 6.19. The ZLS 
                         discs showed similar rod-like grains, n =11.2 +/- 1.4 and m = 
                         9.98. Significance. The FEL and PIC discs showed the lowest 
                         susceptibility to slow crack growth (SCG), whereas the LD and ZLS 
                         discs presented the highest. PIC presented the lowest elastic 
                         modulus and no crystals in its composition, while ZLS presented 
                         tetragonal zirconia. The overall strength and SCG of the new 
                         materials did not benefit from the additional phase or 
                         microconstituents present in them.",
                  doi = "10.1016/j.dental.2016.03.018",
                  url = "http://dx.doi.org/10.1016/j.dental.2016.03.018",
                 issn = "0109-5641 and 1879-0097",
             language = "en",
           targetfile = "ramos_microsctructure.pdf",
        urlaccessdate = "27 nov. 2020"
}


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