Effectiveness of Gutta-percha/Sealer Removal during Retreatment of Extracted Human Molars Using the GentleWave System

The goal of endodontic retreatment is to address the etiology responsible for failure. In order to achieve this, the contents of the previous treatment must be removed. The aim of this study was to compare the effectiveness of the removal of residual obturation material (gutta-percha and sealer) using side-vented needle, EndoVac, and GentleWave (Sonendo, Inc, Laguna Hills, CA) irrigation protocols.

Thirty freshly extracted mandibular molars were instrumented to a master apical file size of 20.06, obturated using continuous wave of condensation and AH Plus sealer (Dentsply Tulsa, Tulsa, OK), restored, and placed in phosphate-buffered saline for 7 days. Teeth were retreated using a crown-down method to a master apical file size of 20.04. Radiographs and micro-computed tomographic images were obtained to confirm the presence of residual obturation material. Teeth were randomly divided among the following treatment groups: a side-vented needle, EndoVac, or GentleWave. Following strict irrigation protocols, postirrigation micro-computed tomographic scans were obtained and used to calculate the percentage of the residual obturation removed.

GentleWave removed more residual obturation material (26%) than the side-vented needle (16%) and EndoVac (9%); the differences between the GentleWave group and the other 2 groups were not statistically significant (P > .05). The difference between the side-vented needle and EndoVac was statistically significant (P = .04).

None of the irrigation techniques were able to completely remove all of the residual obturation material from the canals. The side-vented needle and the GentleWave groups were able to remove on average more residual obturation material than EndoVac; however, the differences were not significant.