I grind my teeth at night too, and to correct this I wear a sports mouthguard in my sleep. You can get them in sporting goods stores or the sporting goods section of a department store. They are very cheap, about $2 or less. The package contains instructions on how to fit them to your teeth. I find when I don't wear it, and grind my teeth in my sleep, I wake up with my head and teeth hurting. This pain can last all day. Also, if you grind your teeth you can wear them down. To avoid this problem, I suggest getting a mouthguard, because that's probably what your dentist will reccommend to you anyways (they may try to sell you a more expensive version, but it's the same thing).