title: Comparison of 2 flushing methods used during passive ultrasonic irrigation of the root canal.
abstract: OBJECTIVE
  To determine the effect of irrigation time on the removal of dentin debris from root canals irrigated with passive ultrasonic irrigation comparing 2 flushing methods.
  
  
  METHODS
  Root canals with a standardized groove in 1 canal wall, which was filled with dentin debris, were irrigated ultrasonically or with syringe irrigation. The quantity of dentin debris after irrigation was determined. In groups 1 to 4, the irrigant was activated by an ultrasonically activated file. In groups 1 and 2 (n = 20), the canals were flushed 3 or 1.5 minutes using a continuous flow of irrigant. In groups 3 and 4 (n = 20), the irrigation time was 1 or 3 minutes, and the canals were flushed 3 times by syringe irrigation (intermittent flushing method). In group 5 (n = 20), the root canals were flushed 3 times using syringe irrigation.
  
  
  RESULTS
  Significantly more dentin debris was removed when the irrigant was activated by ultrasound (P = .000). Significantly less dentin debris was removed when the root canals were irrigated with a continuous flow of irrigant for 1.5 minutes (P = .005).
  
  
  CONCLUSIONS
  Three minutes of ultrasonic irrigation with the intermittent flush technique or a continuous flow is as effective as 1 minute with the intermittent flush technique. The efficiency of the ultrasonic irrigation with a continuous flow is time dependent, 1.5 minutes being less efficient than 3 minutes.
authors.affiliation: Department of Cariology, Endodontology, and Pedodontology, Academic Centre for Dentistry Amsterdam, Amsterdam, The Netherlands. l.vd.sluis@acta.nl
authors.forename: Lucas
authors.initials: L
authors.lastname: van der Sluis
authors.forename: Min-Kai
authors.initials: MK
authors.lastname: Wu
authors.forename: Paul
authors.initials: P
authors.lastname: Wesselink
mesh_terms: D003481:Cuspid / Q000473:pathology; D003786:Dental Pulp Cavity / Q000473:pathology; D003804:Dentin / Q000473:pathology; D006801:Humans; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D018915:Root Canal Preparation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000008:administration & dosage; D013594:Syringes; D007507:Therapeutic Irrigation / Q000295:instrumentation / Q000379:methods; D013997:Time Factors; D014465:Ultrasonics / Q000295:instrumentation; D014732:Vibration
chemical_list: D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite