title: The suitability of packable resin-based composites for posterior restorations.
abstract: BACKGROUND
  Packable composites, promoted for the restoration of stress-bearing posterior teeth, have captured clinicians' interest.
  
  
  METHODS
  The authors tested three packable composites (Alert, Jeneric/Pentron; Solitaire, Heraeus Kulzer, Wehrheim, Germany; SureFil, Dentsply De Trey, Konstanz, Germany); a new packable organically modified ceramic, or ormocer (Definite, Degussa AG, Hanau, Germany); a hybrid composite (Tetric Ceram, Ivoclar Vivadent, Schaan, Liechtenstein) and an ion-releasing composite (Ariston pHc, Ivoclar Vivadent, Schaan, Liechtenstein). They determined modulus of elasticity according to EN 24049:1993 of the European Committee for Standardization. They measured Vickers hardness using a 200-gram load for 40 seconds. To determine the materials' depth of cure, they used both a scraping method (International Standards Organization standard CD 4049:1997) and a hardness profiling method.
  
  
  RESULTS
  The authors calculated means and standard deviations from 10 replications of each test and used one-way analysis of variance and post hoc Tukey tests (alpha = .05). The materials had significant differences (P < .001) in all characteristics. Solitaire had the significantly lowest elastic modulus and microhardness; Alert had the highest values for these characteristics. Ariston pHc exhibited the significantly lowest depth of cure. There was a significant correlation between the two methods of measuring depth of cure (r2 = 0.9945; P = .021).
  
  
  CONCLUSIONS
  The material group of packable composites is rather inhomogeneous in terms of mechanical and physical data. Our data suggest that bulk curing of packable composites in deep cavities still is not recommendable.
  
  
  CONCLUSIONS
  The clinician needs to select packable composites carefully, as it seems that not all of these materials quality for stress-loaded posterior restorations.
authors.affiliation: Department of Restorative Dentistry, Dental School of the Ludwig Maximilians University, Goethestrasse 70, D-80336, Munich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Manhart
authors.forename: H Y
authors.initials: HY
authors.lastname: Chen
authors.forename: R
authors.initials: R
authors.lastname: Hickel
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D002516:Ceramics / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003188:Composite Resins / Q000737:chemistry; D003793:Dental Restoration, Permanent / Q000379:methods; D004548:Elasticity; D006244:Hardness; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D008963:Molar; D012833:Siloxanes / Q000737:chemistry; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013729:Terpenes / Q000737:chemistry
chemical_list: C406265:Alert composite resin; C409382:Ariston pHc; D003188:Composite Resins; C421785:Definite composite resin; D008689:Methacrylates; D012833:Siloxanes; C113049:Solitaire composite resin; C403464:SureFil packable composite; D013729:Terpenes; C121818:Tetric ceram