title: Degradation of dental ZrO2-based materials after hydrothermal fatigue. Part I: XRD, XRF, and FESEM analyses.
abstract: The aim was to investigate the effect of simulated low-temperature degradation (s-LTD) and hydrothermal fatigue on the degradation of three ZrO(2)-based dental materials. Lava, IPS, and NanoZr discs were randomly assigned to (1) Control-Storage in distilled water at 37°C; (2) Aging at 134°C for 5 h (s-LTD); (3) Thermocycling in saliva for 30,000 cycles (TF). XRD revealed that ZrO(2) m phase was identified in all groups but TF increased the m phase only for Lava. Under the FESEM, Lava showed no alterations under s-LTD, but displayed corrosion areas up to 60 µm wide after TF. We conclude that TF accelerated the degradation of Lava through an increase in the m phase and grain pull-out from the material surface.
authors.affiliation: Department of Restorative Sciences, University of Minnesota, Minneapolis, MN, USA. perdi001@umn.edu
authors.forename: Jorge
authors.initials: J
authors.lastname: Perdigão
authors.forename: Ana M
authors.initials: AM
authors.lastname: Pinto
authors.forename: Regina C C
authors.initials: RC
authors.lastname: Monteiro
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Braz Fernandes
authors.forename: Pedro
authors.initials: P
authors.lastname: Laranjeira
authors.forename: João P
authors.initials: JP
authors.lastname: Veiga
mesh_terms: D002563:Cerium / Q000032:analysis; D003343:Corrosion; D003776:Dental Porcelain / Q000737:chemistry*; D003799:Dental Stress Analysis; D006358:Hot Temperature; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning / Q000379:methods; D053758:Nanoparticles; D044367:Phase Transition; D012464:Saliva, Artificial; D013052:Spectrometry, X-Ray Emission; D014961:X-Ray Diffraction; D015019:Yttrium / Q000032:analysis / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D012464:Saliva, Artificial; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D002563:Cerium; D015019:Yttrium; D015040:Zirconium; C028541:zirconium oxide