(PR044) Micro-CT Assessment of Long Oval Root Canal Obturations Using Single-Cone with Apical Negative Pressure

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

Methods: 48 extracted premolars with long oval-shaped canals were selected. The teeth were divided into 4 groups according to the filling technique and materials (n=12): apical negative pressure-assisted NeoSEALER Flo (Avalon Biomed) infiltration with the single-cone technique (NPNF), apical negative pressure-assisted iRoot SP (Innovative Bioceramix, Inc.) infiltration with the single-cone technique (NPS), syringe-assisted NeoSEALER Flo infiltration with single-cone technique (SNF), and syringe-assisted iRoot SP infiltration with single-cone technique (SS). Micro-computed tomography was used at 10 µm resolution to scan the obturated canals. Void percentages, types, and porosity size distribution were calculated from regions of interest. Statistical significance was set at 𝛼=0.05.

Results: None of the filling materials or techniques achieved void-free root canal obturation. Significant difference (p < 0.05) in overall void percentage was found between NPNF (0.75%, IQR 0.93%) and SNF (13.27%, IQR 9.24%) groups, as well as between NPS (0.42%, IQR 0.68%) and SS (15.39%, IQR 13.87%) groups. However, no significant difference (p>0.05) was identified between NPNF and NPS groups, or between SNF and SS groups. Compared with syringe-assisted single-cone technique, the apical negative pressure groups showed a significant reduction in open voids and large porosity sizes (p < 0.05).

Conclusion: Apical negative pressure sealer infiltration combined with single-cone technique demonstrated better filling quality compared to the conventional technique.