title: Fracture resistance of manually and CAD/CAM manufactured ceramic onlays.
abstract: OBJECTIVE
  This in vitro study aimed to evaluate fracture resistance in lithium disilicate onlays fabricated with IPS e.max Press and IPS e.max CAD systems and luted with different adhesive cements.
  
  
  METHODS
  Fifty maxillary first molars were prepared using a mesio-occluso-disto-lingual onlay cavity model. Ten onlays from each group were cemented using etch-and-rinse adhesives and high-viscosity composite resin cement, and 10 were cemented with self-adhesive, dual-curing universal resin cement. Fracture resistance was measured.
  
  
  RESULTS
  Significant differences were observed between resin cements (p < 0.05) and between materials (p < 0.05), but the interaction of these variables did not produce a significant difference. The fracture resistance of pressable ceramics was significantly higher than that of CAD/CAM onlays (p < 0.05), and Syntac Variolink was significantly higher than that of Multilink Sprint (p < 0.05).
  
  
  CONCLUSIONS
  All groups showed clinically acceptable fracture strength results. According to the study, both the onlay fabrication system and adhesive cements can be a viable treatment option.
authors.affiliation: Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Marmara University, Istanbul, Turkey.
authors.forename: Coskun
authors.initials: C
authors.lastname: Yildiz
authors.affiliation: Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Marmara University, Istanbul, Turkey.
authors.forename: Burcin Akoglu
authors.initials: BA
authors.lastname: Vanlıoğlu
authors.affiliation: Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Marmara University, Istanbul, Turkey.
authors.forename: Buket
authors.initials: B
authors.lastname: Evren
authors.affiliation: Associate Professor, Private Practice, Ankara, Turkey.
authors.forename: Altay
authors.initials: A
authors.lastname: Uludamar
authors.affiliation: Professor, Department of Prosthodontics, Faculty of Dentistry, Marmara University, Istanbul, Turkey.
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Kulak-Ozkan
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D002484:Cementation / Q000379:methods; D017076:Computer-Aided Design; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D006801:Humans; D007284:Inlays; D008422:Materials Testing; D008963:Molar; D019279:Resin Cements / Q000737:chemistry; D055116:Self-Curing of Dental Resins / Q000379:methods; D013314:Stress, Mechanical; D014783:Viscosity
chemical_list: C520133:IPS e.max CAD LT; C508050:IPS e.max Press; D019279:Resin Cements; C078484:Syntac dentine adhesive; C493120:lithia disilicate; C502351:multilink adhesive system; D003776:Dental Porcelain; C103502:Variolink
keywords: Ceramic onlays; fracture resistance