question: My Filling had a small crack and I did not know Upper 3rd tooth from top right side.  It got rotten and filling finally came out.  There was hole there right to the root.  Root is dead as per dentist.  Saying I need Root Canal "Apt on Thursday".  Perscribed Clynamicine 150mg 2 tabs 4 times a  day.  My x ray show tooth abcessed into sinus cavity.  My right side maxilliera sinus is hurting extreamly with pressure.  I can breath in through right nostrol but not out nomatter how hard i try.  I did saline flush, Afrine, decongestiants, nothing is working.  Does not seem clynamincine is working i been on it for 3 days with no improvement.