I recently had a root canal and it hasn't been completed as an infection keeps recurring. Now I have a UTI and I read that TMZ ( Bactrim) should not be given for UTI if it occurs after dental work. I am already on my second go round of Clindamycin for the dental infection... I need to see the Dr about the UTI- what should I ask for to treat it? Why isn't Bactrim recommended if the UTI occurs post dental work and can the dental infection be the cause of the UTI?