(PO51) Quantitative evaluation of the fitness of master gutta-percha cones

Abstract: This study aimed to evaluate the fitness of master gutta-percha cones by quantification of the tug-back. Twenty simulated resin canal blocks were used in this study. Resin blocks were prepared with the ProTaper Gold system and the ProTaper Next system. The maximum pulling force was measured by a tension compression sensor to quantify the tug-back. The subgroups of each group were set as the matching GP cone (PTG F2/F3 cone, PTN X2/X3 cone), ISO uniform greater taper (0.04 or 0.06) cone, and nonstandardized cone. Maximum pulling force and placed length of the GP cone were measured 15 times for each specimen. The data were statistically analyzed using 1-way ANOVA and Tukey's post hoc test at the 95% significance level. In the PTG F2 group, the F2 cone group, #25/.06 taper cone group, and medium cone group showed significantly higher pulling force than the #25/.04 taper cone group. In the PTG F3 group, the F3 cone group and #30/.06 cone group showed significantly higher pulling force than other cone groups. In the PTN X2 group, the X2 cone group and medium cone group showed significantly higher pulling force than other cone groups. In the PTN X3 group, the #30/.06 cone group showed a significantly higher value of pulling force than the other cone groups (p > .05). Under the limitations of this study, the measurement of maximum pulling force could allow for the quantification of tug-back, and it would be a more objective indicator of master cone fitting.