title: In vitro fracture resistance of teeth with dentin-bonded ceramic crowns and core build-ups.
abstract: OBJECTIVE
  To assess the fracture strength of dentin-bonded crowns placed on cores of amalgam, resin composite and viscous glass-ionomer.
  
  
  METHODS
  40 sound maxillary premolar teeth were selected. These were mounted in acrylic resin in stainless steel molds. The palatal cusp of each tooth was removed in a standardized manner to simulate a core build-up preparation. Teeth were randomly divided into four groups, and each group was allocated a core material. For Group A, the core was pin-retained amalgam, for Group B the core was bonded amalgam, for Group C the core material was resin composite and for Group D the core material was high-viscosity glass-ionomer material. Cores were then constructed to the original tooth dimensions. A standardized crown preparation was made, impressions taken and an all-ceramic crown constructed in feldspathic porcelain. The crowns were luted in position using a dentin-bonding agent/dual cure resin-composite cement and the completed specimens subjected to compressive loading in a Universal Testing machine at 1 mm/minute.
  
  
  RESULTS
  The mean forces to produce fracture of the crowns were 1.58 kN (+/- 0.41), 1.35 kN (+/- 0.44), 1.25 kN (+/- 0.24), and 1.12 kN (+/- 0.25) respectively for groups A, B, C and D. Statistical analysis by ANOVA indicated that the pinned amalgam group performed significantly better than the glass-ionomer group (P > 0.05).
authors.affiliation: Glasgow Dental School, Scotland.
authors.forename: Mark
authors.initials: M
authors.lastname: Lang
authors.forename: Siobhan
authors.initials: S
authors.lastname: McHugh
authors.forename: F J Trevor
authors.initials: FJ
authors.lastname: Burke
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D000704:Analysis of Variance; D002516:Ceramics / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D019245:Compressive Strength; D003442:Crowns; D003723:Dental Amalgam / Q000737:chemistry; D001840:Dental Bonding; D003772:Dental Pins; D003776:Dental Porcelain / Q000737:chemistry; D017267:Dental Prosthesis Design; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique; D017680:Potassium Compounds / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D014082:Tooth Fractures / Q000503:physiopathology*; D019246:Tooth Preparation / Q000379:methods
chemical_list: D000538:Aluminum Silicates; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D017680:Potassium Compounds; D019279:Resin Cements; D003776:Dental Porcelain; C016447:feldspar; D003723:Dental Amalgam