The invention relates to a tool for filling root canals of teeth in order to prevent bacteria passing thereinto following removal of the nerve from the tooth and preparation of the canal for root filling. Owing to the importance of this remedial action, several methods and tools have been developed to facilitate root canal obturation by injection of a leak-proof material. The present invention discloses a plug made from plastic or any other biocompatible material, comprising: a central, conical, cylindrical, longitudinal cavity； lateral elliptical openings connected to said longitudinal cavity； discontinuous lateral guiding supports having rounded angles and spaces therebetween； and a double leak-proof cap. The plug does not require a gripping part, which facilitates the placement of a post inside the root in order to support fixed prosthodontics and to prevent leakage of the obturating material injected into the tooth.
