title: Irrigant flow within a prepared root canal using various flow rates: a Computational Fluid Dynamics study.
abstract: OBJECTIVE
  To study using computer simulation the effect of irrigant flow rate on the flow pattern within a prepared root canal, during final irrigation with a syringe and needle.
  
  
  METHODS
  Geometrical characteristics of a side-vented endodontic needle and clinically realistic flow rate values were obtained from previous and preliminary studies. A Computational Fluid Dynamics (CFD) model was created using FLUENT 6.2 software. Calculations were carried out for five selected flow rates (0.02-0.79 mL sec(-1)) and velocity and turbulence quantities along the domain were evaluated.
  
  
  RESULTS
  Irrigant replacement was limited to 1-1.5 mm apical to the needle tip for all flow rates tested. Low-Reynolds number turbulent flow was detected near the needle outlet. Irrigant flow rate affected significantly the flow pattern within the root canal.
  
  
  CONCLUSIONS
  Irrigation needles should be placed to within 1 mm from working length to ensure fluid exchange. Turbulent flow of irrigant leads to more efficient irrigant replacement. CFD represents a powerful tool for the study of irrigation.
authors.affiliation: Department of Endodontology, Dental School, Aristotle University of Thessaloniki, Thessaloniki, Greece. chb@dent.auth.gr
authors.forename: C
authors.initials: C
authors.lastname: Boutsioukis
authors.forename: T
authors.initials: T
authors.lastname: Lambrianidis
authors.forename: E
authors.initials: E
authors.lastname: Kastrinakis
mesh_terms: D003198:Computer Simulation; D003786:Dental Pulp Cavity / Q000473:pathology*; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008956:Models, Chemical; D009339:Needles; D012212:Rheology; D012388:Root Canal Irrigants / Q000737:chemistry*; D018915:Root Canal Preparation / Q000295:instrumentation; D012984:Software; D013499:Surface Properties; D013594:Syringes; D007507:Therapeutic Irrigation / Q000295:instrumentation; D019227:Tooth Apex / Q000473:pathology
chemical_list: D012388:Root Canal Irrigants