“How long can you have a cavity before it needs a root canal?”

There is not a single answer to that question. It depends upon how rapidly the decay progresses which depends upon home care, diet, bacteria in the mouth, etc. It is always better to take care of the cavity sooner than later.

Typically a cavity can progress to a point that it damages the nerve and necessitates a root canal in approximately 6-12 months, depending on the oral hygiene condition of the patient. This is why the general rule is to see a dentist at least twice per year for checkups and cleanings, so a cavity does not have a chance to grow that deep. Waiting it out too long is like playing “Russian Roulette”, not a safe bet. Good luck.

Dr. Cyril Tahtadjian