Jaw pain after dental work?

I had a couple of cavities filled about 10 days ago. Ever since I have had severe jaw pain on the right side when I eat or sleep (I do have a tendency to clench in my sleep). I recall the novocaine shot on the right was particularly painful.

The pain radiates from the pack of my jaw up into my ear and down into the lower jaw. It is a sort of dull aching pain the begins at about a 3 and increases to about a 7 or 8 (on a 1-10 pain scale) within about 10 minutes. Two ibuprofen helps the pain and it does not hurt in between meals (even after the ibuprofen wears off.)

The dentist says that it is normal because the novocaine shot is intramuscular, I am just wondering how long I should expect it to hurt.