Baby Grinding Teeth!

My son will be eight months this May and already has seven teeth! I still nurse and I haven't had any trouble with biting yet. Tonight I was giving goodnight snuggles and he was grinding his teeth together. Can that be normal? I am afraid he is going to end up with little tiny nubs for teeth. Not to mention, my poor nipples! Can I get him to stop? Or will he stop on his own? I have already made his first dentist appointment in a week and will ask the dentist. I was just wondering if anyone else had expirience d this?