Re: No decay but extreemly throbbing pain in top front tooth
I DOES sound like a sinus problem. Pressing on the area above the tooth and finding relief sounds as though the tooth root is very close to or into the sinus itself. Did you find any relief with the allergy med? If so, that could be the problem.
Can you try a neti pot? It uses saline to clear the sinuses. It may help.
The only other thing I can think of doing, since your dentist already cleared the tooth itself, is that you may benefit from toothpaste for sensitive teeth. Front teeth are notorious for being sensitive and that may help you. It does take a couple of weeks to work.
If after you have tried this, you still have the problem, you may have a trigeminal nerve problem which can cause shooting pain that can be quite severe.
GOOD LUCK. I hope this helps you and that your problem is an easy fix.
My best to you,