I recently went to the dentist to replace old fillings. but the dentist i went to disfigured the core structure of the tooth in question (reducing my ability to chew efficiently). worst part is that i now feel tooth pain in the area, what must i do?

New Restoration: The old restoration on the tooth in question needed replacement. The new restoration may be deep, resulting in sensitivity which can last for some time. Have the tooth re-evaluated, but if the pain is severe or worsens, the tooth will probably need root canal therapy.

Damaged tooth: Probability is that the tooth was infected (decay) and by the time the dentist finished removing aloft the infection there wasn't much tooth left. You have a choice of either returning to your Dentist for remedial care or seeking treatment elsewhere. Whatever you do, please do it expeditiously.