Typically, teeth are sensitive the first 24 hours after a new filling is placed. After that time, check back with your dentist regarding a possible new development with your tooth.
No, it is not normal, there should be a reason for this.
A tooth may hurt after a filling for a few different reasons. This is only normal for fillings that we would expect it. It is certainly not uncommon as well.
Things that would make a tooth hurt after a filling is the size and location of the filling, the type of material used for the filling, and procedure that was used during the filling. The size and location of the cavity matters because if it was close to the center of the tooth (pulp chamber where the nerve is) this could cause sensitivity. This means that in the area of the filling there is not as much insulation around the tooth. If this is the reason it could be just sensitivity and take some time to dissipate or it could mean a root canal is needed.
The type of material used is important because some of the materials are associated with more sensitivity after a filling. For example, tooth colored fillings have been shown to have more sensitivity after a filling then the old silver ones (one of the reasons silver fillings are still around).
Finally, the procedure used can cause some post-filling sensitivity. If a lot of air was needed to keep the area dry during the procedure, it could have irritated the nerve inside a little. This will usually resolve itself.
If it is still painful after 2 weeks, a visit back to the doctor that did the filling is best. This should not have any additional fee as it is associated with the filling. Hope this helps.
My best to you!
William F. Scott IV, DMD