title: Apical Extrusion of Intracanal Bacteria following use of Two Engine-driven Instrumentation Techniques: An in vitro Study.
abstract: OBJECTIVE
  The aim of the present study was to compare in vitro the amount of debris extruded apically from extracted teeth, using Twisted files and ProTaper rotary during two different instrumentation systems.
  
  
  METHODS
  Forty-five human single-rooted mandibular premolar teeth were randomly divided into three groups and contaminated with Enterococcus faecalis. The teeth in experimental groups were instrumented until reaching the working length with ProTaper rotary instruments and Twisted files with XSmart and XSmart Dual groups. Debris extruded from the apical foramen was collected into glass vials and the amount of bacteria was calculated. The data obtained were analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U tests, with p = 0.05 as the level for statistical significance.
  
  
  RESULTS
  The XSmart Dual group extruded comparatively lesser bacteria compared to the XSmart group. Lesser amount of bacterial extrusion was seen when Twisted files were used compared to the ProTaper files (p < 0.05).
  
  
  CONCLUSIONS
  Under the circumstances of this in vitro study, it can be concluded that all instrumentation techniques produced measurable apical extrusion of debris. So, it is upon the practitioner to decide which system best fits their individual needs and their level of skill and experience that will provide the best possible endodontic care for our patients.
  
  
  CONCLUSIONS
  The newer instrument designs, including noncutting tips, different cross sections, radial lands, and variable tapers, are better for the clinicians to improve working safety, to reduce the working time, and to create a greater flare within the preparations.
authors.affiliation: Department of Conservative Dentistry and Endodontics Kannur Dental College, Kannur, Kerala, India, Phone: +918281588171, e-mail: niyazbond@gmail.com.
authors.forename: Niyaz
authors.initials: N
authors.lastname: Mohammed
authors.affiliation: Department of Conservative Dentistry and Endodontics Kannur Dental College, Kannur, Kerala, India.
authors.forename: M C
authors.initials: MC
authors.lastname: Noushad
authors.affiliation: Department of Conservative Dentistry and Endodontics Kannur Dental College, Kannur, Kerala, India.
authors.forename: Biji
authors.initials: B
authors.lastname: Balan
authors.affiliation: Department of Pedodontics and Preventive Dentistry, Kannur Dental College, Kannur, Kerala, India.
authors.forename: N
authors.initials: N
authors.lastname: Dhanesh
authors.affiliation: Department of Conservative Dentistry and Endodontics Yenepoya Dental College, Mangaluru, Karnataka, India.
authors.forename: Nishi
authors.initials: N
authors.lastname: Jayasheelan
authors.affiliation: Department of Conservative Dentistry and Endodontics, The Vinayaka Mission's Sankarachariyar Dental College, Salem Tamil Nadu, India.
authors.forename: Vanita D
authors.initials: VD
authors.lastname: Revankar
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D015169:Colony Count, Microbial; D003722:Dental Alloys / Q000737:chemistry*; D003786:Dental Pulp Cavity / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000254:growth & development; D004867:Equipment Design; D006801:Humans; D008334:Mandible; D008422:Materials Testing; D009532:Nickel; D012388:Root Canal Irrigants / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods*; D012399:Rotation; D014025:Titanium; D019227:Tooth Apex / Q000382:microbiology*
chemical_list: D003722:Dental Alloys; D012388:Root Canal Irrigants; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Engine-driven; Extruded debris; ProTaper Twisted files.