title: Aging resistance of surface-treated dental zirconia.
abstract: The influence of surface treatment on the low-temperature degradation (LTD) of tetragonal zirconia polycrystalline (TZP) is still unclear.
  
  
  OBJECTIVE
  The effect of surface treatments on the LTD behavior of zirconia was investigated.
  
  
  METHODS
  Fully-sintered specimens of seven commercial dental zirconia (Aadva, GC; In-CeramYZ, VITA; IPS e.max ZirCAD, Ivoclar Vivadent; LAVA Frame and LAVA Plus, 3M ESPE; NANOZR, Panasonic; ZirTough, Kuraray Noritake) were provided by the manufacturers with specimen dimensions of approximately 10mm×5mm×3mm. For each zirconia grade, samples were kept 'as sintered' (untreated) or were subjected to one of the three surface treatments: rough polished, sandblasted with Al2O3, tribochemical silica sandblasted (n=3/group). The tetragonal to monoclinic transformation was evaluated by X-ray diffraction at several intervals during LTD testing up to 40h in steam in an autoclave (134°C, 2bar).
  
  
  RESULTS
  The five yttria-stabilized TZP (Y-TZP: Aadva, In-CeramYZ, IPS e.max ZirCAD, LAVA Frame, LAVA Plus) zirconia showed a similar trend in LTD behavior. The Al2O3 sandblasted zirconia showed the highest monoclinic volume fraction. The as sintered (untreated) zirconia degraded faster than the surface-treated zirconia. Although the surface-treated ceria-stabilized TZP/alumina (Ce-TZP/Al2O3: NANOZR) zirconia had a higher initial monoclinic volume fraction compared to the Y-TZP zirconia, it showed a stronger aging resistance. The as sintered (untreated) Y-TZP/alumina (Y-TZP/Al2O3: ZirTough) zirconia showed a strong aging resistance, whereas the surface-treated Y-TZP/Al2O3 zirconia degraded slightly.
  
  
  CONCLUSIONS
  Surface treatment improved the aging resistance of Y-TZP zirconia. Surface treatment did not affect the LTD behavior of Ce-TZP/Al2O3 zirconia, while surface treatment decreased the aging resistance of Y-TZP/Al2O3 zirconia.
authors.affiliation: KU Leuven BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Kapucijnenvoer 7, blok a bus 7001, B-3000 Leuven, Belgium.
authors.forename: Masanao
authors.initials: M
authors.lastname: Inokoshi
authors.affiliation: Department of Materials Engineering, KU Leuven (University of Leuven), Kasteelpark Arenberg 44, B-3001 Heverlee, Belgium.
authors.forename: Kim
authors.initials: K
authors.lastname: Vanmeensel
authors.affiliation: Department of Materials Engineering, KU Leuven (University of Leuven), Kasteelpark Arenberg 44, B-3001 Heverlee, Belgium.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhang
authors.affiliation: KU Leuven BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Kapucijnenvoer 7, blok a bus 7001, B-3000 Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: De Munck
authors.affiliation: Department of Biomaterials, University of Athens, 2 Thivon Str., Goudi, 115 27 Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Eliades
authors.affiliation: Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8549, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Minakuchi
authors.affiliation: KU Leuven BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Kapucijnenvoer 7, blok a bus 7001, B-3000 Leuven, Belgium.
authors.forename: Ignace
authors.initials: I
authors.lastname: Naert
authors.affiliation: KU Leuven BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Kapucijnenvoer 7, blok a bus 7001, B-3000 Leuven, Belgium. Electronic address: bart.vanmeerbeek@med.kuleuven.be.
authors.forename: Bart
authors.initials: B
authors.lastname: Van Meerbeek
authors.affiliation: Department of Materials Engineering, KU Leuven (University of Leuven), Kasteelpark Arenberg 44, B-3001 Heverlee, Belgium.
authors.forename: Jozef
authors.initials: J
authors.lastname: Vleugels
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D045662:Dental Etching / Q000379:methods; D003776:Dental Porcelain / Q000737:chemistry*; D008422:Materials Testing; D011140:Polyurethanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D003188:Composite Resins; C520133:IPS e.max CAD LT; C485633:In-Ceram Zirconia; D011140:Polyurethanes; C058234:Vita Hi Ceram; C513703:Vivadent; D003776:Dental Porcelain; D015019:Yttrium; D012822:Silicon Dioxide; D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide; C091417:yttria
keywords: Aging; Alumina sandblasting; Low-temperature degradation; Rough polishing; Tribochemical silica sandblasting; Zirconia