title: A new silica-infiltrated Y-TZP obtained by the sol-gel method.
abstract: OBJECTIVE
  The aim of this study was to evaluate silica infiltration into dental zirconia (VITA In-Ceram 2000 YZ, Vita Zahnfabrik) and its effects on zirconia's surface characteristics, structural homogeneity and bonding to a resin cement.
  
  
  METHODS
  Infiltration was performed by immersion of the pre-sintered zirconia specimens in silica sols for five days (ZIn). Negative (pure zirconia specimens, ZCon-) and positive controls (specimens kept in water for 5 days, ZCon+) were also performed. After sintering, the groups were evaluated by X-ray diffraction (XRD), grazing angle X-ray diffraction (DRXR), scanning electron microscopy (SEM), contact angle measurements, optical profilometry, biaxial flexural test and shear bonding test. Weibull analysis was used to determine the Weibull modulus (m) and characteristic strength (σ0) of all groups.
  
  
  RESULTS
  There were no major changes in strength for the infiltrated group, and homogeneity (m) was also increased. A layer of ZrSiO4 was formed on the surface. The bond strength to resin cement was improved after zirconia infiltration, acid conditioning and the use of an MDP primer.
  
  
  CONCLUSIONS
  The sol-gel method is an efficient and simple method to increase the homogeneity of zirconia. Infiltration also improved bonding to resin cement.
  
  
  CONCLUSIONS
  The performance of a zirconia infiltrated by silica gel improved in at least two ways: structural homogeneity and bonding to resin cement. The infiltration is simple to perform and can be easily managed in a prosthesis laboratory.
authors.affiliation: Instituto Tecnologico de Aeronautica (ITA), Praça Marechal Eduardo Gomes 50, 12228-900 São José dos Campos, SP, Brazil.
authors.forename: T M B
authors.initials: TM
authors.lastname: Campos
authors.affiliation: Univ. Estadual Paulista (UNESP), Institute of Science and Technology at São José dos Campos, Department of Dental Materials and Prosthodontics, Eng. Francisco José Longo Avenue 777, 12245-000 São José dos Campos, SP, Brazil.
authors.forename: N C
authors.initials: NC
authors.lastname: Ramos
authors.affiliation: National Institute for Space Research, Associated Laboratory of Sensors and Materials, Astronautas Avenue 1758, 12217-010 São José dos Campos, SP, Brazil.
authors.forename: J P B
authors.initials: JP
authors.lastname: Machado
authors.affiliation: Univ. Estadual Paulista (UNESP), Institute of Science and Technology at São José dos Campos, Department of Dental Materials and Prosthodontics, Eng. Francisco José Longo Avenue 777, 12245-000 São José dos Campos, SP, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Bottino
authors.affiliation: Federal University of Rio Grande do Norte (UFRN), Dentistry Department, 1787 Salgado Filho Avenue, 59056-000 Natal, RN, Brazil.
authors.forename: R O A
authors.initials: RO
authors.lastname: Souza
authors.affiliation: Univ. Estadual Paulista (UNESP), Institute of Science and Technology at São José dos Campos, Department of Dental Materials and Prosthodontics, Eng. Francisco José Longo Avenue 777, 12245-000 São José dos Campos, SP, Brazil. Electronic address: renata.marinho@ict.unesp.br.
authors.forename: R M
authors.initials: RM
authors.lastname: Melo
mesh_terms: D000537:Aluminum Oxide; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D008855:Microscopy, Electron, Scanning; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction; D015040:Zirconium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D003188:Composite Resins; D003764:Dental Materials; D019279:Resin Cements; D014867:Water; D003776:Dental Porcelain; C070870:In-Ceram; D012822:Silicon Dioxide; D019904:Polymethyl Methacrylate; D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide
keywords: Bond strength; Flexural strength; Silica; Sol-gel; Weibull; Zirconia