Cavity filled over month ago. tooth sensitivity esp. to hot/cold food, have returned to dentist twice, xrays, he sees nothing concerning. next step?

Be patient: A deep restoration can result in a sensitive tooth. This can last for a while. Avoid foods that are too hot or cold. Medicaments can be placed, but continued sensitivity may result in the need for root canal therapy.

Tooth sensitivity: A deep filling can remain sensitive for some time, but the sensitivity usually decreases over time. If your dentist has not done so, have your bite checked. A high filling, even if it's just slightly high, can cause sensitivity. Sometimes a filling will need to be removed and the tooth refilled.