title: Fracture Resistance of Molar Crowns Fabricated with Monolithic All-Ceramic CAD/CAM Materials Cemented on Titanium Abutments: An In Vitro Study.
abstract: OBJECTIVE
  To assess the fracture resistance of single-tooth implant-supported crown restorations made with different CAD/CAM blocks.
  
  
  METHODS
  Thirty-six titanium abutments were put on dental implant analogs (Mis Implant). For each of three test groups (n = 12/group), implant-supported, cement-retained mandibular molar single crowns were produced. Crowns were made of lithium disilicate glass (LD) IPS e.max CAD, feldspathic glass ceramic (FEL) Vita Mark II, and resin nano-ceramic (RNC) Lava Ultimate. The crowns were cemented with self-adhesive resin cement RelyX Unicem 2. After chewing cycling, crowns were tested to failure in a universal testing machine. Fracture values were calculated as initial (F-initial) and maximum fracture (F-max).
  
  
  RESULTS
  The study groups were ranked, in order of having highest value, (LD > FEL) > RNC for F-initial load value and (LD > RNC) > FEL for F-max load value. This demonstrated that there was no parallel change in the F-initial and F-max values presenting the fracture resistance of specimens.
  
  
  CONCLUSIONS
  There was no accordance between the F-initial and F-max values of the LD, RNC, and FEL after chewing simulation with thermocycling resembling 5 years of clinical functional use. LD had the highest fracture resistance during the fracture test. RNC had low fracture resistance; however, it had considerably high fracture resistance during the fracture test. FEL had considerably low fracture resistance values.
authors.affiliation: Department of Prosthodontics, Cumhuriyet University Faculty of Dentistry, Sivas, Turkey.
authors.forename: Derya Ozdemir
authors.initials: DO
authors.lastname: Dogan
authors.affiliation: Department of Prosthodontics, Cumhuriyet University Faculty of Dentistry, Sivas, Turkey.
authors.forename: Oguzhan
authors.initials: O
authors.lastname: Gorler
authors.affiliation: Sultanbeyli Oral Health Center, Istanbul, Turkey.
authors.forename: Burcu
authors.initials: B
authors.lastname: Mutaf
authors.affiliation: University of Zurich, Head of Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Zurich, Switzerland.
authors.forename: Mutlu
authors.initials: M
authors.lastname: Ozcan
authors.affiliation: Department of Restorative Dentistry, Karadeniz Technical University Faculty of Dentistry, Trabzon, Turkey.
authors.forename: Gunes Bulut
authors.initials: GB
authors.lastname: Eyuboglu
authors.affiliation: Department of Prosthodontics, Cumhuriyet University Faculty of Dentistry, Sivas, Turkey.
authors.forename: Melih
authors.initials: M
authors.lastname: Ulgey
mesh_terms: D002516:Ceramics; D003188:Composite Resins; D017076:Computer-Aided Design; D003442:Crowns; D000044:Dental Abutments; D003776:Dental Porcelain; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D014025:Titanium
chemical_list: D003188:Composite Resins; C520133:IPS e.max CAD LT; D003776:Dental Porcelain; C023506:Glass ceramics; D014025:Titanium
keywords: CAD/CAM blocks; Dental implant; chewing simulation; feldspathic ceramic; fracture resistance; lithium disilicate ceramic; resin nano ceramic material