Some medications cause dry mouth which increases plaque buildup.
I suggest a sonicare brush used on the "gum care" setting.
This mechanically removes more plaque. Many people do not floss properly.
Make sure your dentist shows you how. There is also an air flosser ( by sonicare)
that is more user friendly o remove debris from between the teeth.
Continue your fluoride rinses.
You may need dental cleanings mor often. Ask your dentist.
Hope this helps you with your problem