Volume and Power of Expansion of Novel Polyurethane-based Sealers

Shrinkage and lack of interfacial adaptation between endodontic sealers and root canal walls may jeopardize the root canal treatment outcome. This study aimed to evaluate the volume and power of expansion (and the relationship between the two) of three novel root canal sealers (polyurethane expandable sealer [PES], zeolite + PES [ZPES], and elastomeric polyurethane sealer [EPS]) in comparison with an epoxy-resin based sealer (AH Plus) and a calcium silicate-based sealer (EndoSequence BC).

This study utilized 36 cylinders (30 plastic graduated cylinders for volume of expansion and 6 steel cylinders for power of expansion) (4 × 10 mm) filled with PES, ZPES, EPS, AH Plus, EndoSequence BC, or water (n = 5/group). The plastic graduated cylinders were inserted inside a customized Linear Swell Meter apparatus to measure the percentage of volumetric expansion. The steel cylinders were placed inside a Linear Swell Meter apparatus mounted onto a universal testing machine to measure the maximum pressure in psi. Specimens were tested for 72 hours for both volume and power of expansion tests. Data were analyzed using Kolmogorov-Smirnov, one-way ANOVA, Post Hoc Tukey, and Pearson correlation tests (P < .05).

The volume of expansion of PES, ZPES, and EPS was significantly higher than in AH Plus and EndoSequence BC (P < .05). For the power of expansion, no significant differences were found between the root-filling materials (P > .05). No correlation was seen between the volume and power of expansion (P > .05).

Although polyurethane-based sealers showed a significantly higher volume of expansion compared to AH Plus and EndoSequence BC, their power of expansion did not increase significantly.