A cyst is a closed sac containing liquids/pus /or soft tissue. It generally
forms around the root tips of infected teeth. Other circumstances in
which a cyst may form include unerupted teeth (buried teeth) or rarely
due to genetic causes.
Sometimes these cysts may go unnoticed without any symptoms and are
detected on x rays as dark holes. Occasionally they may become
infected and form something called an “abscess”.
Small cysts around roots of infected teeth mostly heal by root canal
treatment of the affected tooth alone without any surgery, however large
cysts may require localized surgery to scoop out the cyst and prevent a
new one from forming.