I had my Amalgams removed and 2 Crowns were required on my bottom molars. My teeth were hot cold sensitive for a while but didn't require much pain medication. Now my teeth are normal.
The only trouble I had was one of the molars would pop off every 3 to 6 months. That seems to be fixed now.
Maybe you should get the teeth checked by another dentist to make sure he did the job right. But it could be just an individual thing and the pain should go away soon.