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.
i had a deep cavity filled two weeks ago and it's still sensitive to heat and cold. how long will this last?