Removal of pulp tissue remnants from the isthmus area of lower molars using Shock Wave Enhanced Emission Photo-acoustic Streaming and sonic-activated irrigation.

BACKGROUND

To assess the efficacy of the Er:YAG laser modality Shock Wave Enhanced Emission Photo-acoustic Streaming (SWEEPS), sonic-activated irrigation (SAI), and passive conventional irrigation (CI) in removing pulp tissue remnants (PTR) from the root canal isthmus area in mandibular molars.

METHODS

Forty-six extracted human mandibular molars presenting a continuous isthmus between mesial canals were selected for this study. The specimens were randomly assigned to three experimental groups (n = 12/each) based on the final irrigation (FI) techniques: Group 1, SWEEPS; Group 2, SAI (SmartLite Pro EndoActivator, Denstply Sirona); and Group 3, CI. A control group received no treatment. In the experimental groups, the mesial root canals were initially prepared with a Path File instrument (13/0.02) followed by ProTaper Ultimate up to the instrument F2 (25/0.08), with 3% sodium hypochlorite (NaOCl) as the irrigant. The FI protocol consisted of the sequential application of 3% NaOCl, 15% ethylenediaminotetraacetic acid and 3% NaOCl. After demineralization, histological sections of the isthmus region in the apical third were evaluated, and PTR was measured. Statistical analysis was performed using the Kruskal-Wallis test and post hoc Dunn tests (α = 0.05).

RESULTS

The SWEEPS group demonstrated the lowest PTR values (median PTR: 1.58%), with four samples exhibiting no PTR (p < 0.05). This was followed by the SAI and CI groups, which showed median PTR values of 5% and 7.39%, respectively; however, the difference between these two groups was not statistically significant (p = 0.495).

CONCLUSION

SWEEPS was the most effective technique for removing RPT from the apical isthmus area, while SAI and CI showed similar efficacy.