hello, causes of pain in previously filled/restored tooth mainly includes- 1. high points in restoration/ overfilled tooth leading apical periodontitis
.. ,2. pain in pulp/soft tissue
of tooth as restoration is placed closed to the pulp, and the chemical irritants has leached out to inflammed pulpal tissue,3. inflammation of pulp itself due to pathogens in tubules..
treatment involves in first case occlusal reduction.. and in both second and third case Root Canal
Therapy of tooth..as your pain is severe.. An endodontist will be the best person to perform the procedure..
RCT will ease out your pain completely and your tooth can be saved..
proper clinical examination supported by radiographs (iopa) will diagnose the case.
you can also consult a dentist
and get antibiotic and analgesic
course for few days and get your treatment postponed untill you reach your home country and get treated from your trusted home dentist.. meanwhile avoid any food lodgement in the region by proper flossing and use of antiseptic mouthwashes..