Has anyone had problems with something called black line bacteria?  Well I do.  I gargle, floss twice a day and almost always brush 2 x a day. I became vigilant after I found out that my teeth weren't stained by coffee.  Can't get rid of.  Even the hygienist could not remove all of stains.  My question is beings its a bacteria is there some sort of natural remedy or antibiotic that would rid me of this awful stuff?