Effect of Sonic Agitation of a Binary Mixture of Solvents on Filling Remnants Removal as an Alternative to Apical Enlargement-A Micro-CT Study

Abstract

Background: This work aimed to evaluate the efficacy of sonic agitation of a binary mixture of solvents (methyl ethyl ketone/tetrachloroethylene) on filling remnants removal and compare the effects of solvent agitation with the enlargement to the next instrument size.

Methods: Twenty-four mandibular incisors were prepared with ProTaper Next (X1, X2) and obturated with the single-cone technique and AH Plus sealer. The teeth were retreated with ProTaper Universal Retreatment and ProTaper Next and divided into two groups (n = 12) according to the final instrument (X3 or X4). All canals were submitted to a supplementary procedure consisting of a mixture of solvents-methyl ethyl ketone/tetrachloroethylene, agitated with EndoActivator. The volume of filling remnants was assessed through micro-computed tomography in the apical 5 mm. Statistical analysis was performed with a significance level of 5%.

Results: The supplementary procedure of agitation of the solvent mixture was beneficial in both groups (p < 0.05). There were no statistically significant differences between canals re-prepared until X4 and canals re-prepared until X3 plus solvent (p > 0.05).

Conclusions: An additional step with a two-solvent solution potentiated by EndoActivator showed to be very effective for the removal of gutta-percha and resinous sealer remnants from apical root canals of mandibular incisors, avoiding further enlargement.

Keywords: EndoActivator; gutta-percha; micro-CT; retreatment; sealer; solvents.

Figure 1

Micro-computed tomographic (Micro-CT) images of representative specimens subjected to the different procedures (obturation with X2 gutta-percha cone and AH Plus sealer (G1 and G2); re-preparation until X3 (G1) and X4 (G2); after solvent/EndoActivator (G1 and G2). Green: Gutta-percha; red: Sealer.