Dental Education Lecture: Root tip surgery

Sometimes we may still have pain after root canal, because of the presence of root tip infection.  So we need to remove the root tip.  This exactly happens to a 60-year-old lady, Mrs. Wang.  After root canal, her gums are swollen and reddish (arrowhead in Fig.1).  When the gums are open, two roots are exposed, particularly the root tips (above the dashed lines).  Normal roots are covered by bone; no bone around the root tip suggests root tip infection.  Fig.3 shows this molar tooth after root tip surgery.  This surgery is conservative, as compared to root removal  (Fig.10: everything is removed above the dashed line).  For a tooth to sustain chewing pressure, we can afford to remove a smaller root from a 3-rooted molar (Fig.10).  Since root tip surgery is so conservative, we do it in a single-rooted tooth (Fig.4-7), two roots (Fig.1-3) and even three roots (Fig.8,9) out of  a 3-rooted molar.

Dr. Chen is a medical doctor from China and is doing research in Atlanta.  One day she has toothache.  A lower canine is re-infected (arrowheads in Fig.4) due to suboptimal root canal (R).  Pain disappears after we redo root canal (R in Fig.5).  To be honest with her, we tell Dr. Chen after surgery about a little spill of root canal filling at root tip (* in Fig.5), which should be harmless.  Fourteen months later, she returns, requesting removing the spilled filling material, although she has no physical pain at all.  X-ray shows that root tip infection is gone (Fig.6, as compared to Fig.4).  The spilled filling material breaks down into two small pieces (* in Fig.6).  Finally, the root tip surgery proves to be successful: not any more spilled filling material (Fig.7).  Dr. Chen leaves our dental office without any more psychological pain associated with spilled material.

Mrs. Pan has dull, but persistent pain after root canal.  CT scans clearly demonstrate that there is root tip infection associated with every one of  the three roots (Fig.8,9).  CT scan provides much better resolution images than traditional X-ray.  The former can show early changes and helps the doctor make correct diagnosis.  After root tip surgery, Mrs. Pan also recovers smoothly.

Xin Wei, DDS, PhD, MS 1st edition 03/02/2011, last revision 03/06/2011