Instrument Separation Analysis of Multi-used ProTaper Universal Rotary System during Root Canal Therapy

By Wu J, Lei G, Yan M, Yu Y, Yu J, Zhang G

Date: 02/2011
Journal: JOE


Purpose: to evaluate the separation incidence of reused ProTaper Universal rotary instruments and identify the relevant factors.

N= 6,154 canals /2,654 teeth


•First, glide path created with #10, then SX , WL:#15, THEN  all files starting from S1 to F3 were used.

•Instruments used maximum # were collected and analyzed, fractured instruments examined under stereomicroscope.

•Canals, tooth , curvature were determined according to Schneider et al.

Most highlighted Results:

  • Incidence of instrument separation (table1), separation in relation to tooth type (table 2).
  • Instrument separation in Mand teeth : MB(47.5%), ML(35%) D (17.5%).
  • Instrument separation in MAX teeth : MB (61.5%), DB (30.8%), P (7.7%).
  • Curvature and fracture : sever (54%), moderate (28.6%), mild (17%).
  • 91% of separation happened in the apical 3rd. The rest in the middle. Mean length of 3 mm.