title: The relationship between milling a new silica-doped zirconia and its resistance to low-temperature degradation (LTD): a pilot study.
abstract: The aim of this study was to determine the machinability of new silica-doped Y-TZP by CAD/CAM and the resistance to low temperature degradation of the milled sample by comparing with a commercial HIP type Y-TZP material. The copings could be milled from silica-doped Y-TZP blocks without chipping, and there was no significant difference between the two types of Y-TZP materials in either the marginal or the inner gap between the abutment and the coping. After aging, the monoclinic content in the commercial Y-TZP copings increased from 25% before testing to 65%, while that of silica-doped Y-TZP copings slightly increased from 23% to 30%. The silica-doped Y-TZP copings did not have any significant difference in fracture load in a comparison between the control group and the aging group, while the commercial Y-TZP copings had a significantly lower fracture load for the aging group than for the control group.
authors.affiliation: Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan. tnakamur@dent.osaka-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Usami
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohnishi
authors.forename: Hisataka
authors.initials: H
authors.lastname: Nishida
authors.forename: Xuehua
authors.initials: X
authors.lastname: Tang
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Wakabayashi
authors.forename: Tohru
authors.initials: T
authors.lastname: Sekino
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yatani
mesh_terms: D002516:Ceramics / Q000737:chemistry*; D017076:Computer-Aided Design; D003442:Crowns; D003461:Crystallography; D000044:Dental Abutments; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis / Q000295:instrumentation; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D010865:Pilot Projects; D012822:Silicon Dioxide / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; C499362:yttria stabilized tetragonal zirconia; D014867:Water; D003776:Dental Porcelain; D015019:Yttrium; D012822:Silicon Dioxide; D015040:Zirconium; D014025:Titanium