IADR Abstract Archives

Do surface-treated dental zirconia ceramics degrade?

The influence of surface treatments of dental zirconia (ZrO2) on their low-temperature degradation (LTD) behavior is still unclear. Objectives: Therefore, the effect of four surface treatments on LTD of ZrO2 was investigated. Methods: Fully-sintered zirconia specimens from seven commercial dental zirconia suppliers (Aadva, GC; In-CeramYZ, VITA; IPS e.max ZirCAD, Ivoclar-Vivadent; LAVA Frame, LAVA Plus, 3M ESPE; NANOZR, Panasonic; ZirTough, Kuraray Noritake Dental) were provided. The grain size of all as-received specimens was determined from scanning electron microscopy photomicrographs taken from mirror-polished and thermally etched surfaces. Four groups of each three specimens were subjected to different surface treatments: as sintered (asS); as ground (asG); airborne-particle abraded with alumina (Al2O3); and tribochemical silica-coated with CoJet (3M ESPE). The tetragonal-to-monoclinic zirconia transformation was evaluated during LTD tests up to 40 hours in an autoclave (134°C, 2 bars) by X-ray diffraction (XRD). Results: Five yttria-stabilized zirconia materials (Aadva, In-CeramYZ, IPS e.max ZirCAD, LAVA Frame, LAVA Plus) exhibited similar LTD behaviour. After applying the surface treatments, the monoclinic volume fractions of asS, asG, Al2O3 and CoJet were approximately 1%, 3%, 9% and 7%, respectively. During the LTD tests, the asS group degraded faster as compared to the other groups. Surface-treated ceria-stabilized zirconia/alumina composite specimens (NANOZR) contained a higher monoclinic volume fraction compared to yttria-stabilized zirconia, but revealed a strong ageing resistance. On the other hand, the addition of alumina to an yttria-stabilized zirconia matrix (ZirTough) altered the LTD behavior. The asS yttria-stabilized zirconia/alumina composite specimens (ZirTough) exhibited strong ageing resistance, while their surface-treated specimens slowly degraded. Conclusion: Surface treatments improved the ageing resistance of yttria-stabilized zirconia. They did not affect the LTD behavior of ceria-stabilized zirconia/alumina composite, but decreased the ageing resistance of yttria-stabilized zirconia/alumina composite.


Continental European Division Meeting
2013 Continental European Division Meeting (Florence, Italy)
Florence, Italy
2013
11
Scientific Groups
  • Inokoshi, Masanao  ( KU Leuven BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Leuven, , Belgium )
  • Vanmeensel, Kim  ( Department of Materials Engineering, KU Leuven (University of Leuven), Heverlee (Leuven), , Belgium )
  • Zhang, Fei  ( Department of Materials Engineering, KU Leuven (University of Leuven), Heverlee (Leuven), , Belgium )
  • Minakuchi, Shunsuke  ( Tokyo Medical & Dental University, Tokyo, N/A, Japan )
  • De Munck, Jan  ( KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Leuven, N/A, Belgium )
  • Vleugels, Jozef  ( Department of Materials Engineering, KU Leuven (University of Leuven), Heverlee (Leuven), , Belgium )
  • Naert, Ignace  ( KU Leuven BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Leuven, , Belgium )
  • Van Meerbeek, Bart  ( KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Leuven, N/A, Belgium )
    • Oral Session
    Dental Materials I - Zirconia and Ceramics
    09/05/2013