What is a periapical radiolucency?

I did an experiment to see how google explains in laymen’s terms certain dental terminology. I give Google a “C-“. It does more of a “mansplain” version of an explanation, which cuts corners and can confuse people even more; like giving directions to someone: “Make a left at mile marker five and turn right at the corner where the Piggly Wiggly used to be…”  (Are you kidding me?! What is a Piggly Wiggly?)

A periapical radiolucency is a dark circle or oval seen on a dental x-ray representing a hole in your jaw bone. It is a result of inflammation surrounding the very tip of the root of the tooth; what we call the apex. It can be a precursor to a fistula which creates a path for drainage of inflammation from the jaw bone, into the mouth, rather than allowing it to spread through layers of tissues in the face, neck or under the tongue. This fistula often is detected by the patient as a small pimple which may pop and emit a clear or yellow fluid.

The radiolucency is not the infection. This important concept is often missed: the infection is in the root canal system within the tooth. The radiolucency is just one sign that the root canal is harboring infection.

In any event, this is an indication that the nerve in a tooth has died, and is now necrotic (dead tissue, like gangrene.)

Root canal treatment is needed. This consists of removing the nerve tissue from the small channels (canals) which run down the center of the roots. The final step is then sealing these canals to prevent further bacterial growth.

The goal of getting the tooth treated with a root canal is reduction of the bacteria and removal of the food source that helps bacteria thrive (pulp tissue and inflammatory proteins). The bone will fill back into the hole once the tooth canals are treated and the infection is removed.

The tooth then needs to be built-up with solid foundations called a “core”, followed by capping with a crown.