Spreader penetration during lateral compaction of Resilon and gutta-percha

Resilon, a thermoplastic, polyester polymer-based filling material, is a new material used for sealing root canals after chemomechanical preparation. The purpose of this in vitro study was to compare nickel-titanium (NiTi) spreader penetration in root canals having a .04 taper preparation using .02 and .04 tapered master gutta-percha cones and .02 and .04 tapered master Resilon cones. Twenty canals, from extracted human teeth, were cleaned and shaped to a standardized 40/.04 size. Master cones of .02 or .04 tapered gutta-percha and .02 or .04 tapered Resilon were placed in each canal. A fine-fine NiTi spreader was then placed next to the master cone with a 1.5-kg force. The penetration depth was measured, subtracted from working length, and recorded. A significant difference in penetration depth (p < 0.01) was found for both taper of the cone and material used. The depth of spreader penetration from greatest to least was .02 tapered Resilon, .02 tapered gutta-percha,.04 tapered Resiion, and .04 tapered gutta-percha.