I seem to be getting a big problem with my teeth. A few months ago I found some brownish colouring in between two of my front teeth. It seems to me that it is tooth decay. Since then I have found more brownish discoloration dots on other teeth and also around some of the gum lines. I just cannot seem to be able to brush the colour off, in fact I can't even scrape it off! Can anyone share some light on what this could actually be? And how may I get it fixed (apart from visiting the dentist)?