This was a deep filling with decay close to the nerve. You will have cold sensitivity that will probably last for weeks or months. This is normal.
Your tooth may be sore tonight since we’ve been “stirring things up”. You may want to take something for the pain before the anesthetic wears off and before you go to bed.
After tonight, if the tooth wakes you up at night or hurts for no reason, these may be signs that the tooth is abscessing. At that point, you may need a root canal or you may need to have the tooth pulled.
The longer the tooth goes without problems, the better the chances are that the tooth will be OK. However, sometimes it can take weeks, months or even years for a tooth to abscess.
If you are given an antibiotic, be certain to take it as directed. It is important to take all of the antibiotic, even if your tooth is feeling better.
If you are given a prescription for pain medication, take it with food or milk. Stomach upset is not uncommon. Drowsiness may occur with pain medication, so use caution when driving.