I am 76 . I am still making many appointments with my dentist (at a dental school) for finishing up and perfection. Between appointments is usually 1-2 weeks. In that time I have had plaque on the edges of the "gums". I am very disturbed by this as I use a Water Pik and a Sonicare toothbrush. I am able to keep the teeth clean underneath next to my gums so don't understand why I should be getting plaque. Can you suggest anything?