The flaring efficiency of the Profile and Protaper on resin simulated root canals

Abstract

Forty resin simulated root canals with standardized curvature prepared for this
study, divided into four groups ten canals for each group. Thirty canals were prepared
with rotary endodontic instruments, profile 04, profile 04, 06 and protaper, ten canals
for each type, with slow speed contra angle hand piece (300 rpm) using crown — down
technique the other l0 canals were prepared with stainless steel k-flexo hand
instrument using step — back technique. The total time required for preparation was
calculated. The resin blocks were scanned; the pre-instrumented and post -
instrumented images were stored in the computer and superimposed for two
dimensional evaluation of canals preparation using Adobe photoshope 8.0 and Corel
draw 9. For the coronal portion the amount of canal substance removed was
calculated at 7mm, 9mm, llmm levels from the working length. For the apical
curvature the centering ratio was calculated at 2mm and 4mm level from the working
length. The results showed that the amount of canal substance removed from the
coronal portion by protaper was statistically higher than other groups with statistically
less ability to stay center in the canal than profile rotary instruments but more ability
to preserve apical curvature than k-flexo hand instruments with less time required for
preparation. K-flexo files showed statistically less amount of canal substance removal
at coronal portion and statistically higher centering ratio than other groups, and
require more time for canals preparation .