Apical filling characteristics of carrier-based techniques vs. single cone technique in curved root canals

In this in vitro study, we assessed filling characteristics (adaptation, homogeneity, sealer percentage, position of the carrier) of warm and cold obturation methods in curved root canals. A reciprocating method was used to prepare 90 curved roots (25 A degrees average curvature) to an apical size of 25.08. They were then obturated with either (A) Guttafusion (VDW, Munich, Germany), (B) Thermafil (Maillefer, Ballaigues, Switzerland) or (C) single cone technique using 25.08 gutta-percha (VDW) and sealer (2Seal easymix) (n = 30 each group). Five sections in 1-mm steps were obtained from each root, beginning 1 mm short of the apex. The percentage of voids in contact with root canal walls (PVO), the proportion of voids per area (PVA) and the percentage of sealer per area (PSA) were measured. Little to no differences between Guttafusion and Thermafil were seen in curved root canals with respect to adaptation and homogeneity in the apical region. Both methods showed significantly better adaptation and homogeneity than the single cone technique. The proportion of sealer was significantly greater when roots were obturated with Guttafusion than with Thermafil, but both warm obturation techniques had significantly smaller sealer areas than the single cone technique. Compared to the single cone technique, a more favourable root canal filling with less sealer could be expected from both warm obturation techniques in curved root canals. The easier-to-handle Guttafusion leads to comparable results as Thermafil in curved root canals.