Tooth is pressure sensitive after composite filling, should i be concerned?

Somewhat: Call your dentist, explain the problem and asked to be seen to check the bite and re-evaluate the tooth. A simple bite adjustment often remedies that situation.

Under pressure: When a tooth is worked on to correct an issue there will be resultant inflammation. In most cases the inflammation resolves on its own. Yet if something is not quite right like the bite is off a bit it may cause increased trauma to the tooth. Many times while numb it is difficult to bite properly so when numb is gone you will be more aware and a simple adjustment to bite may be all it needs.