Ok, I decided to come here and ask this cause I am getting kind of anxious before I call my dentist tomorrow. I was wondering if it is possible for sinus drainage to cause a tooth abscess. I have a dull ache in a pre-molar tooth and a foul taste in my mouth. Does anyone know why this is and what could be the cause? Also, I have a very good dental history(if this makes a difference) , only one cavity in my life and no other dental work besides sealants put in about 15 years ago. Hopefully someone can answer this for me, even though it's hard not actually seeing my mouth. Thanks!