The purpose of this study was to evaluate the gutta-percha–occupied area (GPOA) and the relationship between GPOA and tug-back sensations in canals instrumented with reciprocating files.Methods:
Twenty curved canals were instrumented using Reciproc R25 (VDW, Munich, Germany) (group R) and WaveOne Primary (Dentsply Maillefer, Ballaigues, Switzerland) (group W), respectively (n = 10 each). The presence or absence of a tug-back sensation was decided for both of #25/.08 and #30/.06 cones in every canal. The percentage of GPOA at 1-, 2-, and 3-mm levels from the working length was calculated using micro–computed tomographic imaging. The correlation between the sum of the GPOA and the presence of a tug-back sensation was also investigated. The data were analyzed statistically at P = .05.Results:
A tug-back sensation was present in 45% and 100% canals for #25/.08 and #30/.06 cones, respectively, with a significant difference (P < .05). At the 2- and 3-mm levels, #30/.06 cones produced significantly higher GPOA in groups R and W (P < .05). The sum of the GPOA score was significantly higher in the samples with a strong tug-back sensation (P < .05); however, there was no significant difference between the 2 cone types for this correlation (P > .05).Conclusions:
Under the conditions of this study, the tug-back sensation can be a definitive determinant for indicating higher cone fitness in the curved canal regardless of the cone type.