The sealing ability of Thermafil obturators assessed by four different microleakage techniques.

An in vitro investigation was performed to assess the extent of apical dye leakage in relation to root fillings made by Thermafil obturators and the lateral condensation of gutta-percha in extracted human teeth under conditions of passive dye penetration, centrifugation, a vacuum technique and an increased air pressure technique. One hundred and twenty-eight extracted teeth were selected and prepared. The specimens were allocated into eight closely matched experimental groups. Four groups were obturated with Thermafil obturators and four with the lateral condensation technique. Microleakage was assessed after exposing one group of specimens from each of the obturation techniques to each of the four dye penetration systems using India ink as the leakage detector. The teeth were demineralized and cleared prior to examination and the maximum dye penetration for each specimen was recorded. The statistical analysis on transformed data revealed no significant differences between the four microleakage techniques and no differences between the two obturation techniques.

Variation in the microleakage produced by four different techniques in root fillings in a simulated root canal model.

An in-vitro investigation was performed to assess the extent of apical microleakage in simulated canals in clear resin blocks. Four different methods of producing dye penetration were employed: passive dye penetration alone, centrifugation alone, vacuum plus passive dye penetration, and increased pressure plus passive dye penetration. Forty simulated root canals were prepared and obturated. The specimens were randomly allocated into four groups and each group was subjected to a different leakage technique using methylene blue dye as the detector. The maximum apical dye penetration observed through each of the four faces of the blocks was recorded. There were large variations in the leakage recorded in each individual specimen and between the specimens within each group. There were statistically significant differences between passive dye penetration and each of the other three techniques. There was no significant differences between the centrifugation, vacuum and pressure techniques.