Evaluation of four gutta-percha removal techniques for endodontic retreatment

Resumo

The endodontic retreatment is the first choice in cases
of endodontic treatment failure. Objective: To evaluate the ability of
removing gutta-percha from root canal walls, through analyzing the
time and different techniques. Material and methods: Sixty extracted
human mandibular pre-molars were used. After instrumentation with
crown-down technique, the obturation was performed by Tagger’s
hybrid technique. The specimens were divided into 4 groups (n = 15),
according to removal procedure: group I (manual + solvent), group
II (manual + Gates-Glidden + solvent), group III (Protaper Universal
Retreatment System) and group IV (Protaper Universal System +
solvent). The time period for gutta-percha removal was measured
with a stopwatch. The roots were sectioned and the remnants were
visually evaluated, according to the following scores: 0 – without
remnant, 1 – presence of only cement, 2 – presence of cement and
gutta-percha in small amounts, and 3 – presence of cement and
gutta-percha in large amounts. Data were statistically evaluated
with the GraphPad InStat software. Results: Group II exhibited the
shortest time of execution, with significant differences in relation
to groups I and IV, which obtained the longest time periods. Group
III showed an intermediate time period, with statistically significant
differences in relation to group IV. Group IV obtained the best scores
of cleaning, although there was no statistical difference among groups.
Conclusion: There was no statistical significant difference among
the techniques regarding the time and effectiveness in removing
filling material from the root canal walls.