title: Effect of different irrigation protocols on resin sealer bond strength to dentin.
abstract: BACKGROUND
  The aim of this study was to evaluate the influence of different irrigation protocols on resin-based sealer bond strength to dentin and the associated failure pattern.
  
  
  METHODS
  One hundred eighty single-rooted premolars were used. Roots were divided into 18 groups according to the irrigation protocol used and instrumented using 5.25% NaOCl or 2% chlorhexidine (CHX) gel as chemical auxiliary substances and 17% EDTA or 37% phosphoric acid for smear layer removal. Finally, CHX solution was used as the final irrigant in some groups. Root canals were filled with either gutta-percha and AH Plus (Dentsply, Petropolis, RJ, Brazil) (GP/AH) or Resilon/Real Seal SE (SybronEndo, Orange, CA). Bond strength was measured by the push-out test. Additionally, failure patterns were classified as adhesive, cohesive, and mixed. Data were statistically analyzed by Kruskal-Wallis and Mann-Whitney U tests.
  
  
  RESULTS
  In the GP/AH groups, high bond strength values were obtained when NaOCl was associated with phosphoric acid with (6.9 ± 3.9) and without (7.4 ± 3.8) a final flush with CHX. However, when CHX gel was used, the association with EDTA with (7.5 ± 3.2) and without (6.0 ± 2.3) a final flush with CHX solution showed better results. The GP/AH groups mainly showed a cohesive failure pattern. Evaluation of Resilon/Real Seal SE showed that higher bond strength values were reached when CHX was associated with phosphoric acid with (5.2 ± 3.0) and without (4.2 ± 2.0) a final flush with CHX solution. The failure patterns were mainly adhesive.
  
  
  CONCLUSIONS
  Irrigation protocols influenced the bond strength of resin sealers to dentin.
authors.affiliation: Department of Restorative Dentistry, Endodontics Division, State University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Maíra
authors.initials: M
authors.lastname: Prado
authors.forename: Renata A
authors.initials: RA
authors.lastname: Simão
authors.forename: Brenda P F A
authors.initials: BP
authors.lastname: Gomes
mesh_terms: D000268:Adhesiveness; D001641:Bicuspid / Q000648:ultrastructure; D002710:Chlorhexidine / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003786:Dental Pulp Cavity / Q000648:ultrastructure*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D004492:Edetic Acid / Q000737:chemistry; D004853:Epoxy Resins / Q000737:chemistry; D006171:Gutta-Percha / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D010756:Phosphoric Acids / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012388:Root Canal Irrigants / Q000737:chemistry*; D018915:Root Canal Preparation / Q000295:instrumentation; D016369:Smear Layer; D012973:Sodium Hypochlorite / Q000737:chemistry; D013314:Stress, Mechanical; D007507:Therapeutic Irrigation / Q000379:methods*; D019227:Tooth Apex / Q000648:ultrastructure
chemical_list: D003188:Composite Resins; D004853:Epoxy Resins; D010756:Phosphoric Acids; C511498:Real Seal composite resin; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; C534916:epoxy resin-based root canal sealer; C486892:resilon sealer; D006171:Gutta-Percha; D004492:Edetic Acid; D012973:Sodium Hypochlorite; C030242:phosphoric acid; D002710:Chlorhexidine