title: Apical extrusion of debris and irrigant using novel preparation systems.
abstract: OBJECTIVE
  The aim of this in vitro study was to assess the amount of apically extruded debris and irrigant using Reciproc vs self-adjusting fle (SAF) and to investigate the effect, if any, of gravitational force via mandibular and maxillary positioning of the teeth.
  
  
  METHODS
  Forty human mandibular premolars were randomly assigned to four groups of 10 teeth each. The root canals were instrumented according to the manufacturers' instructions using the Reciproc and SAF. Sodium hypochlorite was used as the irrigant. The apically extruded debris was collected in pre-weighted glass vials using the Myers and Montgomery method, and teeth were placed in vials both in downward and upward positions. After drying, the mean weight of debris was assessed with a microbalance and statistically analyzed using two-way ANOVA with Bonferroni correction.
  
  
  RESULTS
  All instrumentation techniques and positions caused measurable apical extrusion of debris. A significant difference was observed according to position and instrument used (p < 0.05). The Reciproc extruded significantly more debris than SAF and vial downward position extruded significantly more debris than upward position (p < 0.05).
  
  
  CONCLUSIONS
  Under the conditions of this study, all systems caused apical debris extrusion, especially in the downward position.
  
  
  CONCLUSIONS
  According to results of this study, the SAF was associated with less debris extrusion compared to the Reciproc in both mandibular and maxillary positions.
authors.affiliation: Research Assistant, Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey, e-mail: emel_dt@hotmail.com.
authors.forename: Emel
authors.initials: E
authors.lastname: Uzunoglu
authors.affiliation: Professor, Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
authors.forename: Melahat
authors.initials: M
authors.lastname: Görduysus
mesh_terms: D004867:Equipment Design; D005547:Foreign Bodies / Q000209:etiology*; D006801:Humans; D008422:Materials Testing; D010486:Periapical Tissue / Q000473:pathology*; D011897:Random Allocation; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D019227:Tooth Apex / Q000473:pathology*; D014732:Vibration
chemical_list: D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite