Patient-friendly definition from the DentistsDirectory.org dental glossary.
An apicoectomy (also called root end surgery) is a minor endodontic procedure in which the very tip of a tooth's root is surgically removed and sealed with a small filling placed from the end. It is typically performed by an endodontist under local anesthesia through a small incision in the gum. The word comes from "apex" (the tip of the root) and "-ectomy" (surgical removal).
The vast majority of root canal infections are successfully treated by cleaning and filling the canal from the top of the tooth. Occasionally an infection persists at the very tip of the root — the periapex — either because the canal anatomy was too complex to fully clean from the inside, because a calcified blockage prevented access, or because the infection reformed after a previous root canal. Approaching the root tip directly through the jaw is the most effective way to eliminate these persistent infections without extracting the tooth.
A small flap of gum tissue is reflected to expose the root end, a few millimetres of the root tip are removed with a small drill, and any infected tissue is cleaned away. A biocompatible filling material is placed in the root end to seal it, and the gum is sutured closed. Most patients experience mild soreness for two to three days, controlled with over-the-counter pain relief. The success rate for apicoectomies performed by endodontists is approximately 85–97%, making it a highly reliable procedure for saving teeth that would otherwise require extraction.