Tooth sensitivity/jaw pain before/post filling

[barcs]

During a recent dental cleaning, two cavities were discovered, one on top and bottom left side. Since I had been experiencing some jaw pain and sensitivity, this was not surprising and the cavities were filled this past Saturday. No pain during procedure or the day of; however the next day, I started feeling vague pain and mild sensitivity. I waited a few days but since the pain worsened, I returned to the dentist yesterday. He checked the bite, probed, and took x-rays and did not see anything concerning. He suggested warm compresses and ibuprofen. The pain continues and actually the tooth sensitivity has worsened over the last day or so. Ibuprofen does help but the fact that nothing is getting better is my main concern. I should add that another concern (and one that may be a factor here) is that I grind my teeth. During the cleaning, I was instructed to purchase a mouth guard at a sporting goods store to get an idea of the degree to which I grind. I have not done this yet, mainly because I'm concerned with my current issue whatever it may be.
Thanks for reading. Any suggestions, experience, ideas?
Matt

[barcs]

Actually, I should add: The pain alternates between pain from the tooth (particularly when liquids touch) to a dull lower jaw pain to odd instances of pain in the cheek and head (perhaps tension headaches). It is not always present but more there than not.