Aim:

To estimate and compare the different obturation techniques to avoid the flow of colorant through lateral canals.

Materials and methods:

50 extracted lower premolars preserved in 5% neutral formol until the moment of use, had artificial lateral canals made. Once canals were instrumented, the teeth were randomly divided into 5 groups (n=10) to be filled with four different techniques: A) System B + injection of thermoplastic gutta-percha, Elements system, Extruder; B) Thermafil, ProTaper Universal obturators; C) hybrid technique, and D) injection of thermoplastic gutta-percha, Elements system, Extruder. Having immersed the premolars in India ink and diaphanized the roots, the penetration length of the India ink inside the canals was assessed. Analysis of variance was used to detect significant differences (P<0.05) between the mean levels of dye penetration according to the filling techniques and tooth areas, and multiple range tests (Tukey’s HSD) were performed for two-to-two comparisons, keeping the error rate per family fixed.

Results:

Technique B had the lowest mean value (30.63%) of penetration. The highest mean values (54.52% and 51.74%) corresponded to techniques A and C, respectively.

Conclusion:

No obturation technique of the root canal used was able to avoid filtration of colourant in the lateral canals.