title: Apically extruded debris with reciprocating single-file and full-sequence rotary instrumentation systems.
abstract: BACKGROUND
  The purpose of this in vitro study was to assess the amount of apically extruded debris using rotary and reciprocating nickel-titanium instrumentation systems.
  
  
  METHODS
  Eighty human mandibular central incisors were randomly assigned to 4 groups (n = 20 teeth per group). The root canals were instrumented according to the manufacturers' instructions using the 2 reciprocating single-file systems Reciproc (VDW, Munich, Germany) and WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) and the 2 full-sequence rotary Mtwo (VDW, Munich, Germany) and ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) instruments. Bidistilled water was used as irrigant. The apically extruded debris was collected in preweighted glass vials using the Myers and Montgomery method. After drying, the mean weight of debris was assessed with a microbalance and statistically analyzed using analysis of variance and the post hoc Student-Newman-Keuls test. The time required to prepare the canals with the different instruments was also recorded.
  
  
  RESULTS
  The reciprocating files produced significantly more debris compared with both rotary systems (P < .05). Although no statistically significant difference was obtained between the 2 rotary instruments (P > .05), the reciprocating single-file system Reciproc produced significantly more debris compared with all other instruments (P < .05). Instrumentation was significantly faster using Reciproc than with all other instrument (P < .05).
  
  
  CONCLUSIONS
  Under the condition of this study, all systems caused apical debris extrusion. Full-sequence rotary instrumentation was associated with less debris extrusion compared with the use of reciprocating single-file systems.
authors.affiliation: Central Interdisciplinary Ambulance in the School of Dentistry, University of Münster, Münster, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bürklein
authors.forename: Edgar
authors.initials: E
authors.lastname: Schäfer
mesh_terms: D000704:Analysis of Variance; D003762:Dental Instruments; D006801:Humans; D007180:Incisor; D018915:Root Canal Preparation / Q000295:instrumentation*; D016369:Smear Layer; D018709:Statistics, Nonparametric; D019227:Tooth Apex