title: Comparison of Apical Extrusion of Debris by Using Single-File, Full-Sequence Rotary and Reciprocating Systems.
abstract: OBJECTIVE
  During root canal preparation, apical extrusion of debris can cause inflammation, flare-ups, and delayed healing. Therefore, instrumentation techniques that cause the least extrusion of debris are desirable. This study aimed to compare apical extrusion of debris by five single-file, full-sequence rotary and reciprocating systems.
  
  
  METHODS
  One hundred twenty human mandibular premolars with similar root lengths, apical diameters, and canal curvatures were selected and randomly assigned to six groups (n=20): Reciproc R25 (25, 0.08), WaveOne Primary (25, 0.08), OneShape (25, 0.06), F360 (25, 0.04), Neoniti A1 (25, 0.08), and ProTaper Universal. Instrumentation of the root canals was performed in accordance with the manufacturers' instructions. Each tooth's debris was collected in a pre-weighed vial. After drying the debris in an incubator, the mass was measured three times consecutively; the mean was then calculated. The preparation time by each system was also measured. For data analysis, one-way ANOVA and Games-Howell post hoc test were used.
  
  
  RESULTS
  The mean masses (±standard deviation) of the apical debris were as follows: 2.071±1.38mg (ProTaper Universal), 1.702±1.306mg (Neoniti A1), 1.295±0.839mg (OneShape), 1.109±0.676mg (WaveOne), 0.976±0.478mg (Reciproc) and 0.797±0.531mg (F360). Compared to ProTaper Universal, F360 generated significantly less debris (P=0.02). The ProTaper system required the longest preparation time (mean=88.6 seconds); the Reciproc (P=0.008), OneShape (P=0.006), and F360 (P=0.001) required significantly less time (P<0.05).
  
  
  CONCLUSIONS
  All instruments caused extrusion of debris through the apex. The F360 produced significantly less debris than did the ProTaper Universal.
authors.affiliation: Associate Professor, Department of Endodontics, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran; Dental Materials Research Center, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Ehsani
authors.affiliation: Assistant Professor, Department of Endodontics, Faculty of Dentistry, Ardabil University of Medical Sciences, Ardabil, Iran.
authors.forename: Robab
authors.initials: R
authors.lastname: Farhang
authors.affiliation: Assistant Professor, Dental Materials Research Center, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran; Department of Endodontics, Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Harandi
authors.affiliation: Postgraduate Student, Department of Oral and Maxillofacial Surgery, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Saeid
authors.initials: S
authors.lastname: Tavanafar
authors.affiliation: Associate Professor, Department of Endodontics, Faculty of Dentistry, Endodontolgy Research Center, Kerman University of Medical Sciences, Kerman, Iran; Laboratory of Molecular Neuroscience, Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Raoof
authors.affiliation: Assistant Professor, Department of Endodontics, Faculty of Dentistry, Ardabil University of Medical Sciences, Ardabil, Iran.
authors.forename: Saeedeh
authors.initials: S
authors.lastname: Galledar
keywords: Dentistry; Endodontics; Instrumentation; Root Canal Preparation