title: Comparison of apical debris extrusion of two rotary systems and one reciprocating system.
abstract: BACKGROUND
  Postoperative inflammation and endodontic failure occur due to apical extrusion of debris.
  
  
  OBJECTIVE
  To evaluate the amount of apically extruded debris after preparation of straight root canals in extracted human teeth using three rotary systems.
  
  
  METHODS
  Sixty single-rooted human teeth with single root canal and apical foramen were selected and randomly divided into three experimental groups (n = 20) according to the rotary system used: Group 1 - ProTaper, Group 2 - Revo-S, Group 3 - WaveOne. Apical enlargement was done up to size 40/0.06 for Groups 1 and 2 and 40/0.08 for Group 3. For debris collection, each tooth was held in a preweighed Eppendorf tube fixed inside a glass vial through rubber plug. After instrumentation, each tooth was separated from the Eppendorf tube and the debris adhering to the root surface was collected by washing the root with 1 mL of bi-distilled water and incubated at 70°C for 5 days. The dry weight of extruded debris was weighed in an electronic balance.
  
  
  METHODS
  The mean weights of extruded debris were statistically analyzed using GraphPad prism version 6 and the intergroup comparison was done using unpaired t-test.
  
  
  RESULTS
  There was a statistically significant difference in the mean debris score among all the three groups - ProTaper (0.00065 g), Revo-S (0.00045 g) and WaveOne (0.00089 g).
  
  
  CONCLUSIONS
  Revo-S system was associated with significantly less debris extrusion compared with ProTaper or WaveOne.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Sree Balaji Dental College and Hospital, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, India.
authors.forename: Paramasivam
authors.initials: P
authors.lastname: Vivekanandhan
authors.affiliation: Department of Conservative Dentistry and Endodontics, Sree Balaji Dental College and Hospital, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, India.
authors.forename: Arunajatesan
authors.initials: A
authors.lastname: Subbiya
authors.affiliation: Department of Conservative Dentistry and Endodontics, Sree Balaji Dental College and Hospital, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, India.
authors.forename: Suresh
authors.initials: S
authors.lastname: Mitthra
authors.affiliation: Department of Conservative Dentistry and Endodontics, Sree Balaji Dental College and Hospital, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, India.
authors.forename: Arumugam
authors.initials: A
authors.lastname: Karthick
keywords: Apical extrusion; ProTaper; Revo-S; WaveOne; debris