title: Fracture resistances of cast metal and ceramic dowel and core restorations: a pilot study.
abstract: OBJECTIVE
  The purpose of this study was to compare fracture strengths of teeth restored with cast metal and ceramic dowel and cores supporting all-ceramic crowns.
  
  
  METHODS
  Eighteen recently extracted teeth were randomly divided into 3 equal groups. Metal dowel and cores (MDC) were fabricated for 1 group using a base metal alloy, and served as the control. The other groups received In-Ceram Spinell (ICS) and IPS Empress 2 (IPS) dowel and cores. IPS Empress 1 crowns were fabricated for all samples. Each tooth was subjected to a shear force at a crosshead speed of 2 mm/min on a universal testing machine until failure occurred.
  
  
  RESULTS
  The mean fracture strengths and standard deviations of MDC, ICS, and IPS restorations were 1101 N (361), 832 N (288), and 1137 N (367), respectively. The differences between groups were insignificant (p < 0.05). Fractures of the all-ceramic crowns were observed in the MDC group, whereas the failure of ceramic dowel and core restorations was associated with root fracture at the cervical region.
  
  
  CONCLUSIONS
  Due to improved mechanical properties, In-Ceram Spinell and IPS Empress 2 ceramic dowel and cores may be candidates for the restoration of endodontically treated anterior teeth.
authors: Department of Prosthodontics, Faculty of Dentistry, Hacettepe University, 06100 Sihhiye, Ankara, Turkey.
authors: Emine
authors: E
authors: Yalçin
authors: Murat C
authors: MC
authors: Cehreli
authors: Senay
authors: S
authors: Canay
mesh_terms: D000537:Aluminum Oxide; D000538:Aluminum Silicates; D000704:Analysis of Variance; D001732:Bite Force; D002516:Ceramics; D002858:Chromium Alloys; D003442:Crowns; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D006801:Humans; D008277:Magnesium Oxide; D008422:Materials Testing; D010865:Pilot Projects; D018583:Pliability; D011176:Post and Core Technique; D011897:Random Allocation; D033081:Shear Strength; D018709:Statistics, Nonparametric; D013718:Tensile Strength
chemical_list: D000538:Aluminum Silicates; D002858:Chromium Alloys; C075815:IPS-Empress ceramic; C111130:spinell; D003776:Dental Porcelain; D008277:Magnesium Oxide; D000537:Aluminum Oxide