hello and welcome to hcm forum,
according to the history presented by you i would like to inform you that your wife is experiencing pain or even sharp sensation due to a faulty restoration, sometimes the filling is too high that when the patient tries to close his /her mouth, sharp shooting pain occurs.
but as you said that your dentist
as already examined, then i would recommend you to get a second opinion
also, because until i check the tooth clinically, i won't be able to give you an accurate diagnosis.
sometimes , even the infection within the tooth if not removed properly prior to the filling can cause pain n swelling, therefore kindly visit a specialist soon,
i wish your wife good health,
thank you for writing to HCM.