title: Effectiveness of several solutions to prevent the formation of precipitate due to the interaction between sodium hypochlorite and chlorhexidine and its effect on bond strength of an epoxy-based sealer.
abstract: OBJECTIVE
  To evaluate the effectiveness of isopropyl alcohol, saline or distilled water to prevent the precipitate formed between sodium hypochlorite (NaOCl) and chlorhexidine (CHX) and its effect on the bond strength of an epoxy-based sealer in radicular dentine.
  
  
  METHODS
  The root canals of 50 extracted human canines (n = 10) were instrumented. In G1, root canals were irrigated with 17% EDTA and 2.5% NaOCl; G2, as G1, except that 2% CHX was used as the final irrigant. In the other groups, intermediate flushes with isopropyl alcohol (G3), saline (G4) or distilled water (G5) were used between NaOCl and CHX. The specimens were submitted to SEM analysis to evaluate the presence of debris and smear layer, in the apical and cervical segments. In sequence, fifty extracted human canines were distributed into five groups (n = 10), similar to the SEM study. After root filling, the roots were sectioned transversally to obtain dentine slices, in the cervical, middle and apical thirds. The root filling was submitted to a push-out bond strength test using an electromechanical testing machine. Statistical analysis was performed using Kruskal-Wallis and Dunn's tests (α = 5%).
  
  
  RESULTS
  All groups had similar amounts of residue precipitated on the canal walls (P > 0.05). The push-out bond strength values were similar for all groups, independently of the root third evaluated (P > 0.05).
  
  
  CONCLUSIONS
  Isopropyl alcohol, saline and distilled water failed to prevent the precipitation of residues on canal walls following the use of NaOCl and CHX. The residues did not interfere with the push-out bond strength of the root filling.
authors: Department of Restorative Dentistry, Araraquara Dental School, UNESP - Univ Estadual Paulista, Araraquara, PS, Brazil.
authors: M G
authors: MG
authors: Magro
authors: M C
authors: MC
authors: Kuga
authors: A J
authors: AJ
authors: Aranda-Garcia
authors: K R
authors: KR
authors: Victorino
authors: G M
authors: GM
authors: Chávez-Andrade
authors: G
authors: G
authors: Faria
authors: K C
authors: KC
authors: Keine
authors: M V R
authors: MV
authors: Só
mesh_terms: D019840:2-Propanol / Q000737:chemistry; D011232:Chemical Precipitation; D002710:Chlorhexidine / Q000737:chemistry*; D003481:Cuspid; D003786:Dental Pulp Cavity; D003799:Dental Stress Analysis; D003804:Dentin / Q000737:chemistry; D004853:Epoxy Resins / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000737:chemistry*; D018915:Root Canal Preparation; D016369:Smear Layer; D012965:Sodium Chloride / Q000737:chemistry; D012973:Sodium Hypochlorite / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004853:Epoxy Resins; D012388:Root Canal Irrigants; D014867:Water; D012965:Sodium Chloride; D012973:Sodium Hypochlorite; D019840:2-Propanol; D002710:Chlorhexidine
keywords: debris; dentine; endodontics; scanning electron microscopy; smear layer