Endodontics: Part 8. Filling the root canal system

The purpose of the obturation phase of a root filling is two-fold; to prevent microorganisms from re-entering the root canal system, and to isolate any microorganisms that may remain within the tooth from nutrients in tissue fluids. The seal at the apical end of the root canal is achieved by a well-fitting gutta-percha master point, and accessory points, although heated techniques may result in a better seal. The seal at the coronal end is achieved by the application of a layer of resin-modified glass ionomer cement as accessory canals may lead from the floor of the pulp chamber to the furcation area. It must always be remembered that success will only be achieved if the root canal system has been as thoroughly debrided as possible of infected material.