An assessment of the plastic Thermafil obturation technique

Summary The effect of post space preparation on the apical seal of teeth roots treated with the plastic‐cored Thermafil was studied in vitro . Single rooted teeth with mature apices were prepared chemomechanically and obturated with alpha‐phase gutta‐percha, Thermafil, on plastic corecarriers and sealer, Sealapex. The teeth were divided randomly into four groups of 18 teeth each. In two of the groups post space was prepared by hand using a Parapost drill (diam. 1.25 mm) after gutta‐percha removal with Peeso reamers in a slow‐speed handpiece, one group immediately after canal obturation and the other after storage in 100% relative humidity at 37°C for 1 week; 5 mm of root filling was left intact. The time taken to remove the gutta‐percha was recorded. Post space was not prepared in the control groups. Apical leakage was determined using black India ink. The teeth were demineralized, rendered transparent, and linear measurement of dye penetration was recorded. Results showed that there were no significant differences in leakage between any of the groups ( P > 0.05). There was no statistically significant difference in the time required to remove the gutta‐percha from the root canals in both groups ( P <0.05). It is concluded that under the conditions of this study post space preparation immediately after obturation, or after a delay of 1 week, does not affect the apical seal of Thermafil with plastic corecarriers.