Machinability and properties of zirconia ceramics prepared by gelcasting method

Abstract

The machinability of newly developed zirconia ceramics for CNC milling was investigated. The zirconia blanks were prepared by the gelcasting method and tested in the green and two pre-sintered states. All blanks exhibited uniform sintering shrinkage in all directions. The blanks were investigated from the viewpoint of surface milling roughness, quality of milled edges and sharp tips, and machinability of thin structures. The best milling results were obtained for the blanks pre-sintered at 900 °C/1 h. Mechanical properties of zirconia blanks, such as biaxial flexural strength, microhardness, indentation elastic modulus, and fracture toughness were determined in the green and pre-sintered states (900 °C/1 h and 1100 °C/1 h) and the

Gelcast Zirconia Ceramics With High Strength and Simultaneously High Translucency for Dental Applications

“…The benefit of the gelcasting method can be also demonstrated on the translucency of alumina-doped 3Y-TZP ceramics prepared from standard 3Y-TZP powder (TZ-3YS-E, Tosoh, Japan) in previous study [41]. Even with this alumina-doped powder (0.25 wt% Al 2 O 3 ), the translucency of the sintered ceramics was close to the highly translucent Nacera Pearl 1 and well above the Ceramill ZI.…”

“…Weibull modulus of 9 obtained in the biaxial test, we could estimate Weibull strengths of 1252 and 1036 MPa in 3-point and 4-point bending, respectively. The measured biaxial strength as well as the estimated 3-point and 4-point flexural strengths were at the top of currently available strengths of high-strength conventional 3Y-TZP [26,41] and overcame the strength of dental 3Y-TZP ceramics with improved translucency and even mostly surpassed the dental low translucent high-strength zirconia (i.e. opaque dental zirconia with alumina doping) [12,30,31,33,34,75,76].…”

“…Zirconia powder SZ (SZ-DT-SE3, JiangXi Size Materials, China) stabilised with 3 mol% of Y 2 O 3 was used to prepare machinable zirconia blanks by the gelcasting method [41]. Zirconia powder was dispersed in a premix solution of monomers, using a commercial Dolapix CE 64 dispersant (Zschimmer & Schwarz, Germany).…”

“…The milling parameters were as follows: depth of cut a p = 0.5 mm and width of cut a e = 0.8 mm for initial roughening, and a p = 0.1 mm and a e = 0.8 mm for finishing in the last step. Further details of milling can be found in our previous study [41]. The milled samples were sintered in an air atmosphere at a heating rate of 10 °C min -1 up to 800 °C, followed by a heating rate of 5 °C min -1 up to the final sintering temperature.…”

Evaluation of the Bonding Strength between Various Dental Zirconia Models and Human Teeth for Dental Posts through In Vitro Aging Tests

“…Currently, common methods include sandblasting [10][11][12][13][14][15][16][17][18], acid etching (hydrofluoric acid) [11,19,20], silicon dioxide coating sandblasting [10,[20][21][22][23], Er: YAG laser irradiation [11,13,24], and the application of coatings containing metal [13]. In addition, it is reported in the literature that the surface roughness can be increased with a proper milling strategy before sintering the zirconia or glass-ceramics [25][26][27].…”