解説An visual explanation of bad root canal therapy .png
English: This X-ray shows two adjacent teeth that had received bad root canal therapy. The root canal filling material (3, 4 & 10) does not extend to the end of the tooth roots (5, 6 & 11). The dark circles at the bottom of the tooth roots (7 & 8) indicated infection in the surrounding bone. Recommended treatment is either to redo the root canal therapy if possible or extract the tooth and place dental implant(s).