title: Effect of passive ultrasonic irrigation and manual dynamic irrigation on smear layer removal from root canals in a closed apex in vitro model.
abstract: OBJECTIVE
  To compare the effect of passive ultrasonic irrigation with manual dynamic irrigation on smear layer removal from root canals using a closed apex in vitro model.
  
  
  METHODS
  The root canals of 45 freshly-extracted human single-rooted mandibular premolar teeth were prepared by the Pro-Taper rotary system to an apical preparation of F4 size. Prepared teeth were randomly divided into three groups; two experimental groups and one control group (n = 15) on the basis of the type of activation of final irrigation as follows: (a) Group A, 3% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA), no activation received; (b) Group B, 3% NaOCl and 17% EDTA, ultrasonic activation with a small file; and (c) Group C, 3% NaOCl and 17% EDTA, manual activation with a master gutta-percha point. The prepared teeth were decoronated and split into two halves longitudinally, and observed under a scanning electron microscope to assess the removal of the smear layer.
  
  
  RESULTS
  In the apical-third region, the mean smear scores for groups B and C were significantly less than those of Group A (control group) (P < 0.05).
  
  
  CONCLUSIONS
  Both activation techniques are important adjuncts in removing the smear layer, with manual dynamic activation being a simpler, safer, and more cost-effective technique.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Dr Ziauddin Ahmad Dental College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
authors.forename: Syed Mukhtar-Un-Nisar
authors.initials: SM
authors.lastname: Andrabi
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
authors.forename: Afaf
authors.initials: A
authors.lastname: Zia
authors.forename: Huma
authors.initials: H
authors.lastname: Iftekhar
authors.forename: Sharique
authors.initials: S
authors.lastname: Alam
authors.forename: Shiraz
authors.initials: S
authors.lastname: Siddiqui
mesh_terms: D003786:Dental Pulp Cavity / Q000187:drug effects / Q000648:ultrastructure*; D004492:Edetic Acid / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D008855:Microscopy, Electron, Scanning; D009339:Needles; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D016369:Smear Layer / Q000648:ultrastructure*; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000627:therapeutic use; D007507:Therapeutic Irrigation / Q000295:instrumentation / Q000379:methods*; D019227:Tooth Apex / Q000187:drug effects / Q000648:ultrastructure; D014465:Ultrasonics / Q000295:instrumentation
chemical_list: D012388:Root Canal Irrigants; D004492:Edetic Acid; D012973:Sodium Hypochlorite
keywords: ethylenediaminetetraacetic acid; irrigant activation; manual dynamic irrigation; passive ultrasonic irrigation; smear layer