I have delevoped some black stains on the backs of two of my front teeth. I have a cleaning again in a few months but wondered if there's anything I can do until then to help the stains go away. I have tried home remedies like baking soda and hydrogen peroxide with no results and a lot if frustration as what to do now. I am worried the stains will set deeper into my teeth or become where they can't be removed before my next cleaning. Can you give me any advice as to what I should do?