Apical negative pressure-enhanced sealer infiltration for obturating long oval-shaped root canals with the...

This study evaluated the effect of apical negative pressure sealer infiltration on void percentage, void types, porosity size distribution, and coronal microleakage in root canal fillings using different hydraulic calcium silicate sealers with the single-cone technique.

Forty-eight extracted premolars with long oval-shaped canals were selected and divided into four groups based on the filling technique and sealer (n = 12): apical negative pressure-assisted NeoSEALER Flo (NPNF), apical negative pressure-assisted iRoot SP (NPS), syringe-assisted NeoSEALER Flo (SNF), and syringe-assisted iRoot SP (SS), all using the single-cone technique. Micro-computed tomography (10 µm resolution) was used to scan the obturated canals. Void percentages, types, and porosity size distribution were analyzed. Statistical significance was set at α = 0.05.

None of the techniques yielded void-free obturations. However, the NPNF (0.75 %, interquartile range 0.93 %) and NPS (0.42 %, IQR 0.68 %) groups showed significantly lower overall void percentages than the SNF (13.27 %, IQR 9.24 %) and SS (15.39 %, IQR 13.87 %) groups (p < 0.05). No significant difference was identified between the NPNF and NPS groups, or between the SNF and SS groups. Apical negative pressure groups also demonstrated significantly fewer open voids and large porosities and reduced microleakage compared to the syringe-assisted groups (p < 0.05).

Apical negative pressure sealer infiltration combined with the single-cone technique significantly improved filling quality and reduced coronal microleakage in long oval-shaped root canals compared to the conventional syringe-assisted single-cone technique.

The use of apical negative pressure for introducing hydraulic calcium silicate sealers during single-cone obturation improves the quality of root canal fillings by reducing the percentage of voids and the presence of large porosities.