Evaluation of different techniques used in non surgical endodontic retreatment for teeth with different obturation techniques : an in-vitro study

Abstract EN

Background : retreatment procedures in endodontic practice require complete removal of the original root filling materials.

The aim of this study was to evaluate the efficacy & time required for rotary Nickel titanium NiTi instruments (Pro-Taper) with and without solvent in the removal of obturation materials during root canal retreatment in comparison with hand instruments using Hedstrom files with solvent in relation to different obturation techniques.

Materials and method : Ninety extracted human roots were instrumented by ProTaper rotary files to (F3) ISO # 30 and the samples were randomly divided into three groups of 30 roots for each group A : obturated by cold lateral condensation technique, group B : obturated by Injectable thermo plasticized technique, group C : obturated by carrier based gutta-percha technique (Soft Core) obturator.

Each main group of roots was randomly subdivided into three subgroups, 10 roots each.

Removal of gutta-percha was performed the following techniques; (1) Pro-Taper without solvent, (2) Pro-Taper with solvent and (3) Hedstrom files with solvent.

The roots were split longitudinally.

The area of remaining filling was evaluated by using stereomicroscope at three levels in the canal and time of retreatment was determined in each group.

Results : One-way ANOVA test indicated that the rotary NiTi instruments Pro-Taper with and without solvent left significantly less remaining filling materials (P < 0.001) compared to Hedstrom files with solvent while there was no significant difference at (p < 0.05), between Pro-Taper with solvent and without solvent.

In groups obturated by cold lateral condensation and injectable thermo plasticized techniques left significantly less remaining filling materials at (p < 0.05), than group obturated by soft core obturator.

The retreatment time was significantly less at (P < 0.001) when the rotary NiTi Pro-Taper instrument was used compared to hand.

Conclusion : ProTaper rotary instrument with and without solvent was found to be effective and faster than hand instruments and Cold lateral condensation technique and inject able thermo plasticized technique better removed in retreatment than Soft Core obturator technique.