title: Effect of endodontic irrigants on microtensile bond strength to dentin after thermocycling and long-term water storage.
abstract: OBJECTIVE
  The bond strength of adhesives in irrigated dentin behaves differently over time. The aim of this study was to evaluate the influence of long-term water storage and thermocycling on the microtensile bond strength of adhesive systems to dentin irrigated with endodontic solutions.
  
  
  METHODS
  Sixty human molars were used after removal of the occlusal portion and exposure of the dentin by grinding. The specimens were irrigated with 2.5% NaOCl for 30 minutes and then 17% EDTA for 5 minutes and assigned to six groups according to the adhesive system (n=10): G1 and G2-Clearfil SE Bond; G3 and G4-Single Bond 2; and G5 and G6-XP Bond. The teeth were restored with composite and were subjected to water storage for different time periods. G1, G3 and G5 were stored for 24 h; G2, G4 and G6 were stored for 6 months and were subjected to thermocycling (12,000 cycles, 5°C to 55°C, 500 cycles per week for 6 months). After storage, the tooth/restoration assembly was sectioned to obtain four sticks of approximately 1 mm(2), for microtensile bond strength testing. The results were analyzed by two-way ANOVA and Tukey's test.
  
  
  RESULTS
  Significant differences were observed among the adhesives (p<0.01). No significant differences were observed in the microtensile bond strength between samples after 24 hours of storage without thermocycling and after 6-month storage with 12,000 cycles (p<0.05).
  
  
  CONCLUSIONS
  The bond strengths of G5 and G6 after irrigation with 2.5% NaOCl and 17% EDTA were significantly different from those of other groups. Long-term water storage/thermocycling had no effect on bond strength to dentin.
authors.affiliation: Department of Operative Dentistry, RibeirãoPreto School of Dentistry, University of São Paulo, RibeirãoPreto, Brazil.
authors.forename: Daniel
authors.initials: D
authors.lastname: Galafassi
authors.affiliation: Department of Operative Dentistry, RibeirãoPreto School of Dentistry, University of São Paulo, RibeirãoPreto, Brazil.
authors.forename: Vivian
authors.initials: V
authors.lastname: Colucci
authors.affiliation: Assistant Professor, Department of Endodontics, University of Passo Fundo, Passo Fundo, Brazil.
authors.forename: Doglas
authors.initials: D
authors.lastname: Cecchin
authors.affiliation: Department of Pediatric dentistry, RibeirãoPreto School of Dentistry, University of São Paulo, RibeirãoPreto, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Scatena
authors.affiliation: Associated Professor, Department of Operative Dentistry, RibeirãoPreto School of Dentistry, University of São Paulo, RibeirãoPreto, Brazil.
authors.forename: Telma N
authors.initials: TN
authors.lastname: Nascimento
authors.affiliation: Associated Professor, Department of Operative Dentistry, RibeirãoPreto School of Dentistry, University of São Paulo, RibeirãoPreto, Brazil.
authors.forename: Silmara A M
authors.initials: SA
authors.lastname: Corona
keywords: EDTA; Microtensile Bond Strength; NaOCl; Self-etch; Total-etch