I recently noticed a yellow buildup that feels very gritty at times on the front and back side of my lower facial teeth (4 lower front teeth). The back side appears thicker and more widespread than the front. Also, the back side appears to be chipping off along the edges of each tooth. I initially thought that I was loosing enamel, but last night another piece came off while I was flossing and I could see white beneath it (not dark dentin). I accidental chewed a small piece and it was very easy to chew—it instantly turned to a powder in my mouth. I read that tartar is hardened plaque that can be a brown to yellow color, and that only dentists can remove it. Is it possible that the chipping is tartar and not my enamel? If it is enamel, would I be able to chew the pieces into a powder with one light bite? I'm only 28 years old and brush and floss fairly regularly. However I haven't been to a dentist in 4 or so years. I do have an appointment in a few weeks—should I be concerned about this and try to see the dentist as early as possible?

—Peter in Massachusetts

Dear Peter,

You need a professional cleaning, bad. Yes, this is calculus, otherwise known as tartar. It isn't enamel. And it's causing gum disease and possibly other problems.

Tartar buildup is the main reason you need to visit your dentist every 6 months. When you're young, you don't have this. But when you hit your twenties, this starts to build up and you need to get it scraped off by your friendly dental hygienist to keep gum disease under control.

—Dr. Hall

A diagram of tartar on teeth

An actual photograph of tartar in the mouth