title: Effect of Tooth-Colored Restorative Materials on Reliability of Heat-Pressed Lithium Disilicate.
abstract: OBJECTIVE
  Restorative material selection in complete mouth rehabilitation is an important factor in long-term management of potential technical complications. The aim of this study was to evaluate in vitro the reliability (fracture resistance) of lithium disilicate fatigued with different restorative materials.
  
  
  METHODS
  A step-stress accelerated life-testing model was used. Seventy disc specimens were heat-pressed. Five groups of different indenter materials fatigued the lithium-disilicate specimens: group WC (tungsten carbide served as a control), group PR (interpenetrating polymer network [IPN] resin-based denture tooth), group POM (heat-pressed leucite glass-ceramic), group LD (heat-pressed lithium disilicate), and group ZR (zirconium dioxide). Lithium-disilicate specimens were randomly divided into four groups (n = 14). Specimens were fatigued to failure according to three step-stress profiles: light, moderate, and aggressive. Use level probability Weibull plots were generated, and each group's reliability, failure rate, and mean life to failure were calculated.
  
  
  RESULTS
  The IPN resin-based denture tooth group had the highest reliability and mean life to failure, and lowest failure rate as compared to lithium disilicate and zirconium dioxide. No significant difference existed between the reliability of the tungsten carbide and leucite glass-ceramic groups and the IPN resin-based denture tooth group.
  
  
  CONCLUSIONS
  Lithium-disilicate specimens fatigued with IPN resin-based denture teeth exhibited higher reliability than specimens fatigued with lithium disilicate and zirconium dioxide. There was a difference in fracture characteristics in lithium-disilicate specimens fatigued with tungsten carbide, lithium disilicate, and zirconium dioxide, versus those fatigued with IPN resin-based denture teeth and leucite glass-ceramic material.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.
authors.forename: Tijana
authors.initials: T
authors.lastname: Stijacic
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.
authors.forename: Kwok-Hung
authors.initials: KH
authors.lastname: Chung
authors.affiliation: Department of Materials Science and Engineering, University of Washington, Seattle, WA.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Flinn
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.
authors.forename: Ariel J
authors.initials: AJ
authors.lastname: Raigrodski
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry; D003116:Color; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis / Q000379:methods; D003778:Dentures; D006358:Hot Temperature; D006801:Humans; D019279:Resin Cements / Q000737:chemistry; D017973:Tungsten Compounds / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D003764:Dental Materials; D019279:Resin Cements; D017973:Tungsten Compounds; C493120:lithia disilicate; C002802:tungsten carbide; D003776:Dental Porcelain; C078519:leucite; C023506:Glass ceramics; D015040:Zirconium; C028541:zirconium oxide
keywords: Lithium disilicate; denture teeth; heat-pressed ceramics; leucite glass-ceramics; zirconium dioxide