title: Enhancing the bond of a resin-based sealer to root dentine.
abstract: OBJECTIVE
  To evaluate whether application of a total-etch/separate adhesive layer can enhance the bond of a UDMA-based sealer to dentine.
  
  
  METHODS
  The root canals of 20 decoronated maxillary premolar teeth with two canals were prepared to size 35-45, 0.04 taper using rotary NiTi instruments. The canals of each tooth were treated with application of either a total-etch/separate adhesive or the manufacturer-recommended primer, before root filling with sealer plus matching master cone using warm vertical compaction. After setting, roots were sectioned perpendicular to the long axis to obtain 1-mm-thick slices, and the root filling was subjected to the push-out test using a plunger closely matched to canal diameter. The roots of another 15 single-rooted premolars were sectioned in a bucco-lingual direction, and the cut surfaces were ground flat for microshear bond strength testing. One-half of the specimens were coated with a separate total-etch/adhesive layer, and then, a cylinder of sealer cement 1 mm diameter × 1.5 mm high was bonded to the prepared surface of all specimens. Microshear bond strength was measured in a universal testing machine after 48 h. Data were analysed using anova and paired t-tests, with significance set at P < 0.05.
  
  
  RESULTS
  Use of a separate total-etch/adhesive markedly increased both microshear bond strength and push-out strengths compared with standard primer (P < 0.001).
  
  
  CONCLUSIONS
  Application of a separate adhesive layer significantly increases bond strength of UDMA-based sealers to root dentine.
authors: Melbourne Dental School, The University of Melbourne, Melbourne VIC Australia.
authors: M
authors: M
authors: Rahimi
authors: A
authors: A
authors: Jainaen
authors: P
authors: P
authors: Parashos
authors: J
authors: J
authors: Palamara
authors: H H
authors: HH
authors: Messer
mesh_terms: D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D045662:Dental Etching / Q000379:methods*; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates; D011140:Polyurethanes; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation; D033081:Shear Strength
chemical_list: D003738:Dental Cements; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D011140:Polyurethanes; D012387:Root Canal Filling Materials; C486892:resilon sealer; C029824:urethane dimethacrylate luting resin