A Comparison of Apical Bacterial Extrusion in Manual, ProTaper Rotary, and One Shape Rotary Instrumentation Techniques.

By Mittal R, Singla MG, Garg A, Dhawan A.

Date: 01/2015
Journal: JOE


Purpose: To assess the bacterial extrusion by using manual, multiple-file continuous rotary system (ProTaper) and single-file continuous rotary system (One Shape).

N= 42 human mandibular premolars were inoculated with Enterococcus faecalis by using a bacterial extrusion model.


  • The teeth were divided into 3 experimental groups (n = 12) and 1 control group (n = 6).
  • The root canals of experimental groups were instrumented according to the manufacturers’ instructions by using manual technique, ProTaper rotary system, or One Shape rotary system.
  • Test apparatus  Fig 1
  • Sterilized saline was used as an irrigant, and bacterial extrusion was quantified as colony-forming units/milliliter.
  • The results obtained were statistically analyzed by using one-way analysis of variance for inter-group comparison and post hoc Tukey test for pair-wise comparison.

Most highlighted Results:

  • All the instrumentation techniques resulted in bacterial extrusion, with manual step-back technique exhibiting significantly more bacterial extrusion than the engine-driven systems.
  • Of the 2 engine-driven systems, ProTaper rotary extruded significantly more bacteria than One Shape rotary system.
  • Table 1

Clinical significance:

The engine-driven nickel-titanium systems were associated with less apical extrusion. The instrument design may play a role in amount of extrusion.