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Abstract
This study was designated to evaluate the efficacy of a relatively new
rotary Ni -Ti instrument (RaCe) in root canal retreatment.
Sixty maxillary molars were selected. Forty of them were decoronated
and the palatal root was hemisectioned. The roots were instrumented using Kfiles
in a step back technique until reaching MAF of size 60. The roots were
obturated with gutta percha and AHplus sealer using lateral condensation
technique. According to the retreatment method the roots were divided into two
groups and two subgroups according to the type of irrigant used:
Group 1 subgroup A:
10 samples were retreated using RaCe with chlorhexidine gel.
Group 1 subgroup B:
10 samples were retreated using RaCe with chloroform.
Group 2 subgroup A:
10 samples were retreated using H-files and chlorhexidine gel.
Group 2 subgroup B:
10 samples were retreated using H-files and chloroform.
The amount of apically extruded debris was measured and the time
needed for retreatment was calculated.
The roots were then grooved buccolingually and split into two halves
using a chisel. The amount of remaining filling material on the canal walls was
photographed using a stereomicroscope and calculated using image analysis
software.