Sinus squeeze can cause referred pain in the upper teeth, and it can definitely feel like only one tooth is involved. Tooth squeeze can of course occur in both upper and lower teeth, but the fact that it's in an upper tooth makes the diagnosis more complicated. A dental xray should be able to pinpoint an air space beneath a filling. If the dentist says the filling is ok, a visit to an ENT physician would be in order.
Meanwhile, over-the-counter decongestants and non-steroidal anti-inflammatories (e.g. acetaminophen, ibuprofen) may provide some temporary relief while you await medical consultation. Oxymetazoline nasal spray is pretty benign provided it's not used more than three days in a row. It could also be diagnostic if you use the nose spray and the pain goes away. Of course the standard disclaimer applies: check for allergies and drug interactions, follow all medication directions carefully, check with your physician if you're already taking any medications, and stop taking medications if you experience any adverse side effects.
If your dentist and/or local physician are unfamiliar with barotrauma and need to consult with us, our number is on the website linked below.
Best regards,
DDM