Apicoectomy also known as root resection, retrograde root canal treatment or root-end filling, is a surgical procedure whereby a tooth's root tip is removed and a root end cavity is prepared and filled with a biocompatible material. It may be performed with a microscope. This is usually done when a conventional root canal treatment has failed and a re-treatment was already unsuccessful or is not advised. Various materials are used as a filling material for apicoectomy. They are:Amalgam
Amalgam is widely used as a root-end filling, and meets many of the desired criteria. It is easy to handle, easy to see on radiographs, not sensitive to moisture, and stable at body temperature. Amalgam provides a relatively good seal if placed correctly. There have been some concerns about toxicity, as amalgam contains mercury as an ingredient, but there is very little evidence to support these.Composite Resin
Composite resin is commonly used as a filling material due to its aesthetic qualities and ability to effectively bond to tooth,especially enamel. It is less commonly used as a root-end filling material, as its placement is technique sensitive, particularly to moisture. Moisture contamination will result in a weakened bond which may cause leakage and subsequent failure;but when placed correctly, composite resin can produce high success rates.Mineral Trioxide Aggregate (MTA)
MTA is a cement containing mineral oxides which absorb water to form a colloidal gel, which solidifies over a period of approximately 4 hours. It has proven very popular as a root-end filling material and has shown generally high success rates. MTA produces a high pH environment, which is bactericidal, and may stimulate bone forming cells also known as Osteoblasts to produce bone to fill in any defects caused by infection.Zinc Oxide Eugenol Cement
Modified versions of ZOE cement, such as IRM or Super EBA, have high compressive strength, high tensile strength, neutral pH, and low solubility and serve as good root end filling materials.