Just joined the forum after googling for "pressure after refill hot cold". I just had to share my dental experience and hope that it'll help others.
I have bad dental record genetically. I floss, rinse with mouthwash and brush twice daily. Yet, there's at least a cavity every 6 months per visit. 18 months ago, I had four (in 6 months) much to my chagrin. Luckily, I have a high threshold for pain.
Despite the cavities, I've been going to the same dentist for 7 years and had 1 root canal. Unfortunately, in my recent visit, I needed a refill (I've alway had white filling). Immediately after the refill, I sensed that it didn't go well. Shortly after the novocaine wore off in mid-day, I felt pain on pressure while chewing and sensitivity to hot and cold that evening. Usually, I was able to resume normal activities at the end of day. This time, however, all three symptoms persist 5 days after the refill.
After my first (pleasant) experience with root canal and the pain that preceded it, I knew that I need another visit to my endodontist. It's been over 3 weeks and nothing has changed thus far. Instead of revisiting the dentist, I self-diagnosed and booked an appointment to get the issue resolved (I hope!). I'd like to chew on it again.
So, if you've never had problems with white fillings and experience pressure and sensitivity to hot and cold that does not go away after 2 weeks of a refill, it's highly indicative that you'd need a root canal. In most cases, see your dentist to make sure that you'd need one.
Always trust dental referals from friends and colleagues. if the dentist is trustworthy and his endodontist and wisdom tooth surgeon-dentists referals are rather untarnished, it's likely that you've found a good dentist. Also, switch to Sonicare toothbrush if you can afford it. It's cost you just one filling ($130).