An evaluation of .06 tapered gutta-percha cones for filling of .06 taper prepared curved root canals

Aim To compare the area occupied by gutta‐percha, sealer, or void in standardized .06 tapered prepared simulated curved canals and in mesio‐buccal canals of extracted maxillary first molars filled with a single .06 gutta‐percha point and sealer or lateral condensation of multiple .02 gutta‐percha points and sealer. Methodology Simulated canals in resin blocks with either a 30° curve and radius of 10.5 mm (n = 20) or a 58° curve and 4.7 mm radius (n = 20) and curved mesio‐buccal canals of extracted maxillary first molars (n = 20) were prepared using .06 ProFiles® in a variable tip crown‐down sequence to an apical size 35 at 0.5 mm from the canal terminus or apical foramen. Ten 30° and 58° curved resin canals and 10 canals in the extracted teeth group were obturated with .02 taper gutta‐percha cones and AH 26 sealer using lateral condensation. The time required to obturate was recorded. The remaining canals were obturated with a single .06 taper gutta‐percha cone and AH 26 sealer. Excess gutta‐percha was removed from the specimens using heat and the warm mass vertically condensed. Horizontal sections were cut at 0.5, 1.5, 2.5, 4.5, 7.5 and 11.5 mm from the canal terminus or apical foramen. Colour photographs were taken using an Olympus 35 mm camera attached to a stereomicroscope set at ×40 magnification, and then digitized using a flatbed scanner. The cross‐sectional area of the canal contents was analysed using Adobe PhotoShop®. The percentage of gutta‐percha, sealer or voids to the total root canal area were derived and data analysed using unpaired Student's t‐test and the Mann–Whitney U‐test. Results In the 30° curved canals the levels had between 94 and 100% of the area filled with gutta‐percha with no significant difference (P > 0.05) between the lateral condensation and single cone techniques. In the 58° curved canals the levels had 92–99% of the area filled with gutta‐percha, with the single cone technique having significantly (P 0.05) between the lateral condensation and single cone technique. The time for obturation was significantly (P