Teeth are held in the jaw by their roots, which have nerves inside of them. When tooth decay or an injury damages the tooth, it can cause the nerve to die. This will eventually result in the formation of an abscess at the tip of the root, deep inside your jaw. Root fillings involve removing damaged or dead nerves and after careful cleaning the root canals are filled. This allows us to reconstruct the tooth that is left. The success rate of root fillings is around the 85% mark as long as no root treatment has been done before. The success rate of a re-root filling (an attempt has been made before but it has not been successful) is much lower at around 50%.
If an abscess is diagnosed a course of antibiotics will only suppress the infection but it will never solve the problem as the source of the infection (the dead nerve) is not removed. A successful root treatment or an extraction will achieve this. You can give yourself the best possible chance of avoiding an abscess by having tooth decay treated at the earliest possible stage. The deeper the decay, the more chance you will have of the nerve dying off. It comes as a surprise to many patients that many root treatments can actually be done without making it numb as the nerve has died. We will however usually give you a local anaesthetic as you will be more comfortable that way. The images below show the sequence of a root filling needing to be done as a result of tooth decay:
Deep tooth decay has not only destroyed a large part of the molar, it has also damaged the nerve which has died off as a result. The remnants of the dead nerve are poisoning the jawbone at the tip of the root as that is where there is an opening for all these toxins to leak out of the root.
The tooth decay has been cleaned out and a beginning has been made in removing the dead (necrotic) nerve tissue. The top part or pulp chamber has been cleaned but the root canals have not been accessed yet.
The root canals are cleaned by using endodontic files. The intention is to remove all the infected material from the root canal system which, is often not just one root canal but depending on which tooth is treated it can be as many as 5 main canals with lateral canals as well. Intermittently a disinfectant is flushed through the canals to clean the inside of the tooth in order to leave no bacteria behind.
After the cleaning has been completed, the root canals are filled to avoid re-infection. The material used is Gutta Percha which is bio compatible and inert natural rubber and acts like a plug. It is compacted into the canals by applying some heat to the material after which it can be compressed further into canals further.
As the root canals are now filled, the tooth needs to be restored in a way it can withstand the chewing forces so often a fiberglass post is inserted into the canal around which a core can be constructed out of composite material.
With the root filling now completed, it is time to restore the tooth/molar as strongly as possible. As it was extensively damaged by tooth decay, a crown is often the best way to build the tooth up again