What causes nerve pain after getting teeth filled?

See Dentist: The dentist needs to evaluate several possibilities: 1) the filling may be too high causing you to bite on that area first. = needs adjustment. 2) the nerve may be dying and may need a root canal treatment. 3) the interior of the tooth may have a faulty bond in the filling placement.

Nerve inflamed: It's quite common to have some sensitivity following the placement of a filling. Drilling and filling a tooth is actually a micro-surgical procedure on the tooth. The nerve becomes temporarily inflamed and may cause sensitivity. If this does not resolve within a few days, see your dentist to determine if something else needs to be done for the tooth (bite adjustment or something else)?

Inflamation: All fillings are somewhat traumatic to the pulp. The deeper the filling, the greater the inflamation. In shallow fillings, there may be no sensitivity. With deep fillings, the inflamation may not resolve and root canal may be necessary. Mild cold sensitivity will resolve in a few wks. Severe lingering cols sensitivity will take longer. If a tooth is also heat sensitive, or if heat causes lingerii.