The present invention is directed to root canal obturation in a tooth. In one embodiment, a plug is positioned in a root canal and bonded to the root canal by applying a light-curing adhesive to the canal and exposing the plug to a light source to bond the plug to the root canal. In another embodiment, a carrier is disclosed having an optically transmissive plug portion for insertion into the canal. In still another embodiment, the plug portion of the carrier includes an optical fiber to transmit light from a light source into the plug portion. In still yet another embodiment, a filler material is heated and injected into the root canal in a semi-liquid state and exposed to light to cure the adhesive.