Why are my crowns bleeding even after getting a 2nd crown replacement when I complained it was bleeding the first time?

I have had two crown put in two different I notice after them being put in the right side was bleeding I would place my tongue on it and I could taste the blood. And when I floss it would bleed more I went to the dentist and they placed a whole new crown on the right side and I see a black dot is that the excess cement? And now the 2nd crown is still bleeding. I was told I had fine gums. Also the other crown on the left side when I floss bleeds. They told me to use this rinse called peridex.

No doctor answers yet