 [ Symptoms ] i had a deep cavity filled two weeks ago and it is still sensitive to heat and cold how long will this last [ Disease ] it is not unusual to have sensitivity after a deep filling it could last 8 12 weeks the most important thing to know is if there is a change for the worse you may have an irreversibly damaged nerve that can get infected this would require root canal therapy to save the tooth i would carefully monitor your symptoms and get in touch with the dentist if something changes