title: Removal of intracanal smear by doxycycline in vitro.
abstract: Cleansing and shaping result in a smear layer on the instrumented canal wall surfaces. The smear layer may inhibit close contact between sealers and dentin, and inhibits diffusion of medicaments.
  
  
  OBJECTIVE
  This study assessed the effect of doxycycline hydrochloride (DH) on smear layer on intracanal walls.
  
  
  METHODS
  Scanning electron microscopy was used to evaluate the remaining smear layer using different concentrations of DH. Single-canal palatal roots of extracted maxillary molars were irrigated with saline-15% EDTA; saline-25 mg/ml DH; saline-50 mg/ml DH; saline-100 mg/ml DH; NaOCl-15% EDTA; NaOCl-25 mg/ml DH; NaOCl-50 mg/ml DH; and NaOCl-100 mg/ml DH. The roots were fractured into halves and the amount of smear layer assessed in the middle and apical third.
  
  
  RESULTS
  Doxycycline-HCl of 100 mg/ml was the most effective in removing smear layer. In the saline group, 100 mg/ml of DH was more effective than EDTA. In the hypochlorite group, 50 mg/ml and 100 mg/ml of DH were more effective than EDTA (p < 0.05).
  
  
  CONCLUSIONS
  Doxycycline solution may be an effective irrigant.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of California, San Francisco, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Barkhordar
authors.forename: L G
authors.initials: LG
authors.lastname: Watanabe
authors.forename: G W
authors.initials: GW
authors.lastname: Marshall
authors.forename: M Z
authors.initials: MZ
authors.lastname: Hussain
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D003786:Dental Pulp Cavity / Q000187:drug effects / Q000648:ultrastructure*; D003804:Dentin / Q000187:drug effects / Q000648:ultrastructure*; D004318:Doxycycline / Q000627:therapeutic use*; D004492:Edetic Acid / Q000627:therapeutic use; D006801:Humans; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000379:methods*; D016037:Single-Blind Method; D016369:Smear Layer; D012965:Sodium Chloride; D012973:Sodium Hypochlorite / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D012388:Root Canal Irrigants; D012965:Sodium Chloride; D004492:Edetic Acid; D012973:Sodium Hypochlorite; D004318:Doxycycline