Does anybody know what this might mean? I have been getting a continual build up of plaque on my teeth. To the point it's like chalk or something.

This is mainly behind the two bottom front teeth to the point I find I have to scrape them with something often to stop this. My gum have also receded. This seemed to start folling a course of antibiotics last year and has never ceased since.

I do not know what is going on and cannot just go into a dentist because I get extremely ill frm the mercury vapor in the office. Does anybody understand what might be happening here? I brush morning and night and I floss....