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File Techniques

Step back technique
  • Access coronal portion and middle third with a gates glidden drill
  • Establish working length using small flexible file and locate the apex
  • Step back from the apex, while increasing file size
  • Once we get to the middle portion of the canal, you may switch back to Gates Gliddens
  • Your goal is to achieve a funnel shape
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    The "Step Back" method indicates that the dentist works from the bottom of the canal back towards the crown. Following the bulk removal of the pulp in the extirpation phase, small hand files are used nearest the apex. The dentist progresses to larger sizes of files working his or her way back up the canal. Each file cuts and removes a little bit more dentin. Usually these advance about one millimeter with each new instrument. Towards the mid-root area, the dentist will switch to Peeso Reamers or Hedstrom files. Gates Glidden instruments are generally reserved for shaping the coronal third of the canal.

    Crown down technique
  • Begin at the coronal portion with gates gliddens
  • Continue down the canal, reducing the size of each file as you get closer to the apex
  • Your goal is to achieve a funnel shape

    • The second method or technique is called "Crown Down". In the crown down technique the dentist essentially works from the crown of the tooth, shaping the canal as he or she moves towards the apex. The instruments are used in a large to small sequence. The first instruments are the gates gliddens which do the coronal flaring. The Peeso Reamers or Hedstrom files follow in the mid-root region. Finally, progressively smaller files take the dentist towards the apex.

    Circumferential filing
  • Instrumentation of all walls equally during the root canal preparation
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    Balanced force technique
  • Maintaining a balance position in the canal relative to all walls, the instrument is inserted and turned first clockwise (then counter clockwise while maintaining apical pressure) and then removed.
  • Nickel titanium files are the instrument of choice with the balanced force technique
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    Master apical file
  • Largest file used at the working length
  • Used to determine working length
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    Patency file
  • Smallest file used to maintain a clear canal
  • Master apical file
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    Recapitulation
  • Repeatedly going to the apex with the patency file to deter build up of dentinal debris
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