title: Smear layer removal and canal cleanliness using different irrigation systems (EndoActivator, EndoVac, and passive ultrasonic irrigation): field emission scanning electron microscopic evaluation in an in vitro study.
abstract: BACKGROUND
  The purpose of this study was to evaluate the effectiveness of different irrigating methods in removing the smear layer at 1, 3, 5, and 8 mm from the apex of endodontic canals.
  
  
  METHODS
  Sixty-five extracted single-rooted human mandibular premolars were decoronated to a standardized length of 16 mm. Specimens were shaped to ProTaper F4 (Dentsply Maillefer, Ballaigues, Switzerland) and irrigated with 5.25% NaOCl at 37°C. Teeth were divided into 5 groups (2 control groups [n = 10] and 3 test groups [n = 15]) according to the final irrigant activation/delivering technique (ie, sonic irrigation, passive ultrasonic irrigation [PUI], or apical negative pressure). Root canals were then split longitudinally and observed by field emission scanning electron microscopy. The presence of debris and a smear layer at 1, 3, 5, and 8 mm from the apex was evaluated. Scores were analyzed by Kruskal-Wallis and Mann-Whitney U tests.
  
  
  RESULTS
  The EndoActivator System (Dentsply Tulsa Dental Specialties, Tulsa, OK) was significantly more efficient than PUI and the control groups in removing the smear layer at 3, 5, and 8 mm from the apex. The EndoVac System (Discus Dental, Culver City, CA) removed statistically significantly more smear layer than all groups at 1, 3, 5, and 8 mm from the apex. At 5 and 8 mm from the apex, PUI and the EndoVac did not differ statistically significantly, but both performed statistically better than the control groups.
  
  
  CONCLUSIONS
  In our study, none of the activation/delivery systems completely removed the smear layer from the endodontic dentine walls; nevertheless, the EndoActivator and EndoVac showed the best results at 3, 5, and 8 mm (EndoActivator) and 1, 3, 5, and 8 mm (EndoVac) from the apex.
authors.affiliation: Department of Restorative Dentistry and Endodontics, University of Rome "Tor Vergata", Rome, Italy. Electronic address: manuele.mancini@tiscali.it.
authors.forename: Manuele
authors.initials: M
authors.lastname: Mancini
authors.forename: Loredana
authors.initials: L
authors.lastname: Cerroni
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Iorio
authors.forename: Emiliano
authors.initials: E
authors.lastname: Armellin
authors.forename: Gabriele
authors.initials: G
authors.lastname: Conte
authors.forename: Luigi
authors.initials: L
authors.lastname: Cianconi
mesh_terms: D000293:Adolescent; D000328:Adult; D003786:Dental Pulp Cavity / Q000648:ultrastructure*; D003804:Dentin / Q000648:ultrastructure; D004492:Edetic Acid / Q000008:administration & dosage; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D018915:Root Canal Preparation / Q000295:instrumentation; D016369:Smear Layer / Q000473:pathology / Q000628:therapy*; D012973:Sodium Hypochlorite / Q000008:administration & dosage; D013010:Sonication / Q000295:instrumentation; D013696:Temperature; D007507:Therapeutic Irrigation / Q000295:instrumentation*; D019227:Tooth Apex / Q000648:ultrastructure; D014465:Ultrasonics / Q000295:instrumentation; D014618:Vacuum; D055815:Young Adult
chemical_list: D012388:Root Canal Irrigants; D004492:Edetic Acid; D012973:Sodium Hypochlorite
keywords: EndoActivator System; EndoVac System; field emission scanning electron microscopy; irrigant activation; passive ultrasonic irrigation; smear layer