Fillings
It is common to have sensitivity when chewing and with temperature changes, after treatment by dental fillings, but this induced sensitivity is reversible in most cases.
These symptoms, will eventually fade and disappear after a few days to a few weeks.
The spontaneous pain on a tooth are on the contrary, a sign of irreversible inflammation of the nerve, which may require a root treatment.
In this case it would be better to inform your dentist of these symptoms.