When you discover a hole in your tooth, obviously a visit to the dentist is required. The dentist will examine the tooth/teeth and decide on either a filling or root canal work.
A filling is generally for less severe cavities where the erosion has only eaten through two layers – the enamel and the dentin.
If the cavity is deeper and is accompanied by nerve damage and maybe also pain, root canal therapy is the best solution.
“Fortunately, a root canal isn’t much different from getting a filling these days. Technology has made it possible for your root canal to be performed with no pain and you’ll be able to save your natural tooth!”
Find out more about the differences in treatment for cavities here: https://yourdentalhealthresource.com/is-a-filling-okay-or-will-i-need-a-root-canal/