Effectiveness of resin-coated gutta-percha cones and a dual-cured, hydrophilic methacrylate resin-based sealer in obturating root canals

The introduction of a polybutadiene-diisocyanatemethacylate resin-coating of gutta-percha enables the polyisoprene to be chemically coupled to methacrylate-based resin root canal sealers. This study examined the effectiveness of using passively fitting cones of this type of gutta-percha with a dual-cured version of EndoREZ sealer in obturating cleaned and shaped root canals. The hydrophilic nature of the sealer enabled the creation of an extensive network of 800 to 1200 μm long sealer resin tags after removal of the endodontic smear layer. Although no adhesive was employed, thin hybrid layers in root dentin were observed when EDTA was used as the final rinse. Nevertheless, interfacial gaps and silver leakage could be observed along the sealer-dentin interfaces that might be attributed predominantly to polymerization shrinkage of the sealer. Gaps and silver leakage were also identified between the gutta-percha resin-coating and the sealer.