title: Polymerization stress, flow and dentine bond strength of two resin-based root canal sealers.
abstract: OBJECTIVE
  To compare two resin-based root canal sealers (AH Plus and dual cure Epiphany) in terms of flow, polymerization stress and bond strength to dentine.
  
  
  METHODS
  Flow was evaluated by measuring the diameter of uncured discs of sealer (0.5 mL) after 7 min compression (20N) between two glass plates (n = 5). Polymerization stress was monitored for 60 min in 1-mm thick discs bonded to two glass rods (Ø = 5 mm) attached to a universal testing machine (n = 3). Bond strength was analyzed through micropush-out test (n = 10) and failure mode was examined with scanning electron microscope (100x and 2500x). Data were statistically analyzed using the Student's t-test (alpha = 0.05).
  
  
  RESULTS
  Polymerization stress was 0.32 +/- 0.07 MPa for Epiphany self-cure, 0.65 +/- 0.08 MPa for Epiphany light-cure and zero for AH Plus (P < 0.05). Flow data and bond strength values were 30.9 +/- 1.1, 28.6 +/- 0.7 mm and 6.3 +/- 5.3, 17.8 +/- 7.5 MPa for Epiphany and AH Plus, respectively (P < 0.001). Failure mode was predominantly cohesive in the sealer for both materials.
  
  
  CONCLUSIONS
  Epiphany had higher flow and polymerization stress and lower bond strength values to dentine than AH Plus. In view of these findings it can be implied that AH Plus would provide a better seal.
authors.affiliation: School of Dentistry, Federal University of Maranhão, São Luiz, MA 65085-580, Brazil. sosocarvalho@usp.br
authors.forename: S F C
authors.initials: SF
authors.lastname: Souza
authors.forename: A C
authors.initials: AC
authors.lastname: Bombana
authors.forename: C
authors.initials: C
authors.lastname: Francci
authors.forename: F
authors.initials: F
authors.lastname: Gonçalves
authors.forename: C
authors.initials: C
authors.lastname: Castellan
authors.forename: R R
authors.initials: RR
authors.lastname: Braga
mesh_terms: D001840:Dental Bonding; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D004853:Epoxy Resins / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D012212:Rheology; D012387:Root Canal Filling Materials / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D004853:Epoxy Resins; D008689:Methacrylates; D011108:Polymers; D019279:Resin Cements; D012387:Root Canal Filling Materials; C486893:epiphany sealer; C534916:epoxy resin-based root canal sealer