The dental filling of channels is practiced when the pulpis (the soft inner structure of the tooth, where the blood vessels and nerves are) is inflamed or infected, usually as a consequence of caries or damages The infected pulpis is extracted , the channels are cleaned and then filled, in order to avoid further inflammation. The infected pulpis can’t be left without treatment, otherwise there will be an “abscess” and a significant discomfort, and if there is no treatment, the tooth will probably have to be extracted.

The yellow arrow demonstrates “the hollow” part of the tooth, not filled with a material. The blue arrow indicates the uncommon body in the channel: after the extraction of the umcommon body and the preparation of “the hollow” part, the channel is finally cured and filled (red arrow).