In Vivo Debridement Efficacy of Ultrasonic Irrigation Following Hand-Rotary Instrumentation in Human Mandibular Molars

By Gutarts R, Nusstein J, Reader A, Beck M.

Date: 01/2005
Journal: JOE


Purpose:  to histologically compare debridement efficiency of a hand/rotary cleaning and shaping technique versus a hand/rotary cleaning and shaping /ultrasound technique in the mesial roots of human mandibular molars.

  • N= 36 vital mandibular molars (mesial root only)


  • Sample were devided into G1 (16): hand/rotary instrumentation, G2 (15): hand/rotary/ultrasound, G3 (5): control.
  • In G1, the canals were prepared initially by hand K files to #20 then rotary Profile GT files in a crown-down technique.
  • 6% NaOCL was used to irrigate the canals during the procedure. Finally, the canals were flushed with 15 ml of 6% NaOCL for 1 min.
  • In G2, the canals were prepared as in G1 with the addition of an ultrasonically energized needle (MiniEndo system) used to deliver the 15 ml of 6% NaOCL for 1 min after completion of the hand/rotary preparation.
  • After extraction and histologic preparation, 0.5 μm cross-sections from the 1- to 3-mm apical levels, were evaluated for percentage of tissue removal.

Most highlighted Results: 

Mean percentages of canal and isthmus cleanliness values were significantly higher for group 2 at all levels evaluated.

Clinical significance

The 1-min use of ultrasonically activated irrigation, following hand/rotary cleaning and shaping, has been shown to improve canal and isthmus cleanliness.