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  • Article
    Citation - WoS: 12
    Citation - Scopus: 11
    Enhanced Bioactivity and Low Temperature Degradation Resistance of Yttria Stabilized Zirconia/Clay Composites for Dental Applications
    (Elsevier Sci Ltd, 2022) Tufan, Yigithan; Park, Jongee; Ozturk, Abdullah; Ercan, Batur
    Yttria stabilized zirconia (YSZ)/clay composites were produced to improve osseointegration and undesired tetragonal-to-monoclinic phase transformation (low temperature degradation, LTD) of YSZ ceramics so that long-term clinical success of YSZ implants is achieved. Various amounts (0.5,1,2, and 4 wt%) of clay was incorporated to YSZ. Predetermined amounts of clay and YSZ were mixed and pressed uniaxially at 15 MPa into compacts that were subsequently pressureless sintered at 1450 degrees C. Density, compressive strength, hardness and indentation crack resistance of 4 wt% clay incorporated YSZ/clay composite were 5.77 +/- 0.01 g/cm3, 1188 +/- 121 MPa, 1223 +/- 9 HV, and 4.4 +/- 0.1 MPa root m, respectively. Additionally, biological properties of YSZ/clay composites were assessed in vitro using bone cells. Incorporation of 4 wt% clay significantly enhanced bone cell prolifer-ation, spreading, and functions. Moreover, a significant increase in the LTD resistance of YSZ was achieved upon 4 wt% clay incorporation. The findings collectively suggest that YSZ/clay composites have a potential to be used as an alternative material for dental applications.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 14
    Tribological Behavior of Alumina-Added Apatite-Wollastonite Glass-Ceramics in Simulated Body Fluid
    (Elsevier Science Sa, 2010) Park, Jongee; You, Sang-Hee; Shin, Dong-Woo; Ozturk, Abdullah
    Tribological properties of an alumina-added apatite-wollastonite glass-ceramic produced by controlled heat treatment of a glass in the system MgO-CaO-SiO(2)-P(2)O(5)-Al(2)O(3) have been evaluated and compared with those of selected commercial dental ceramics, Duceragold and IPS Empress. Tribological tests were performed in dry condition and in simulated body fluid (SBF) using a pin-on-disk apparatus. The friction coefficient and specific wear rate of the tested materials were measured in dry and in artificial saliva (simulated body fluid: SBF) in order to elucidate the appropriateness of the alumina-added apatite-wollastonite (A-W) glass-ceramic for dental applications. Wear rate of the materials investigated varied from 0.96 x 10(-4) mm(3) N(-1) m to 41.37 x 10(-4) mm(3) N(-1) m depending on the bioenvironmental test conditions. The results of this study revealed that the alumina-added A-W glass-ceramic becomes more wear resistant as sintering temperature is increased and exhibits tribological properties similar to those of the commercial dental materials investigated. (C) 2010 Elsevier B.V. All rights reserved.