Theory One...File Short Fill Short

• The Concept is that any microbes or debris left in the apical unprepared portion of the canal will be handled by the body's natural defenses.
• Advantages
  
  • Rarely get and overfill since you deliberately stay away from the apex.
  • Rarely overinstrument unless an error is made.
    
• Disadvantages
  
  • Leave debris in apical area which the body may not be able to handle.
  • Frequently Blocked Out since patency is never attained, debris tends to build up at the bottom of the preparation.
    
  • Frequently Ledge since the buildup of debris tends to prevent instruments from following the canal when curved.

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