title: Chemical analysis of the flocculate formed by the association of sodium hypochlorite and chlorhexidine.
abstract: OBJECTIVE
  The association of chlorhexidine (CHX) and sodium hypochlorite (NaOCl) to enhance their chemical properties during root canal biomechanical preparation can lead to a brown flocculate being formed. Therefore, this study evaluated the metals present in their association by atomic absorption spectrophotometry, and evaluated a possible reagent that could dissolve the flocculate, allowing its clinical use.
  
  
  METHODS
  Five concentrations of CHX and NaOCl were mixed (2.5% NaOCl + 0.2% CHX, 2% CHX + 0.5% NaOCl, 2% CHX + 5% NaOCl, 0.2% CHX + 0.5% NaOCl, and 0.2% CHX + 5% NaOCl). Methanol and hexane, acetic acid, and vinegar were evaluated to dissolve the flocculate.
  
  
  RESULTS
  A flocculate was formed with all proportions and concentrations. Spectrophotometry analysis showed the presence of Ca, Fe, and Mg.
  
  
  CONCLUSIONS
  It can be concluded that the association proposed led to the formation of brown flocculate regardless of concentration and proportion.
authors.affiliation: Department of Dentistry, Endodontic Department, University of Ribeirão Preto, Sao Paulo, Brazil.
authors.forename: Melissa Andréia
authors.initials: MA
authors.lastname: Marchesan
authors.forename: Braulio
authors.initials: B
authors.lastname: Pasternak Júnior
authors.forename: Márcia Maisa de Freitas
authors.initials: MM
authors.lastname: Afonso
authors.forename: Manoel Damião
authors.initials: MD
authors.lastname: Sousa-Neto
authors.forename: Cristina
authors.initials: C
authors.lastname: Paschoalato
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D002118:Calcium / Q000032:analysis; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000737:chemistry; D004338:Drug Combinations; D005427:Flocculation; D007202:Indicators and Reagents / Q000737:chemistry; D007501:Iron / Q000032:analysis; D008274:Magnesium / Q000032:analysis; D012388:Root Canal Irrigants / Q000737:chemistry*; D018915:Root Canal Preparation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013054:Spectrophotometry, Atomic
chemical_list: D004338:Drug Combinations; D007202:Indicators and Reagents; D012388:Root Canal Irrigants; D012997:Solvents; D012973:Sodium Hypochlorite; D007501:Iron; D008274:Magnesium; C010882:chlorhexidine gluconate; D019342:Acetic Acid; D002710:Chlorhexidine; D002118:Calcium