| Autor: |
Theocharopoulos, Antonios L., Bushby, Andrew J., P'ng, Ken M. Y., Wilson, Rory M., Tanner, K. Elizabeth, Cattell, Michael J. |
| Předmět: |
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| Zdroj: |
Journal of Advanced Prosthodontics; Dec2016, Vol. 8 Issue 6, p479-488, 10p |
| Abstrakt: |
PURPOSE. The aim of this study was to test the modulus of elasticity (E) across the interfaces of yttria stabilized zirconia (YTZP) / veneer multilayers using nanoindentation. MATERIALS AND METHODS. YTZP core material (KaVo-Everest, Germany) specimens were either coated with a liner (IPS e.max ZirLiner, Ivoclar-Vivadent) (Type- 1) or left as-sintered (Type-2) and subsequently veneered with a pressable glass-ceramic (IPS e.max ZirPress, Ivoclar-Vivadent). A 5 μm (nominal tip diameter) spherical indenter was used with a UMIS CSIRO 2000 (ASI, Canberra, Australia) nanoindenter system to test E across the exposed and polished interfaces of both specimen types. The multiple point load - partial unload method was used for E determination. All materials used were characterized using Scanning Electron Microscopy (SEM) and X - ray powder diffraction (XRD). E mappings of the areas tested were produced from the nanoindentation data. RESULTS. A significantly (P<.05) lower E value between Type-1 and Type-2 specimens at a distance of 40 μm in the veneer material was associated with the liner. XRD and SEM characterization of the zirconia sample showed a fine grained bulk tetragonal phase. IPS e-max ZirPress and IPS e-max ZirLiner materials were characterized as amorphous. CONCLUSION. The liner between the YTZP core and the heat pressed veneer may act as a weak link in this dental multilayer due to its significantly (P<.05) lower E. The present study has shown nanoindentation using spherical indentation and the multiple point load - partial unload method to be reliable predictors of E and useful evaluation tools for layered dental ceramic interfaces. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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