Here are tips for protecting your pearly whites:
Work to relieve stress. Regular meditation, deep breathing, exercise and enjoyable hobbies will help; some people also benefit from talking to a therapist. It's especially good to do right before bedtime. Take a bath, listen to soft music, read a favorite book or drink a glass of warm milk. Holding a warm washcloth against your jaw for about 10 minutes can help relax those muscles.
Wear a mouth guard. Protective dental devices keep teeth from rubbing together at night. Custom-made guards -- available from your dentist -- are more expensive than over-the-counter varieties, but they're typically less likely to dislodge during grinding.
Cut back on alcohol and caffeine. Both can make a grinding problem worse, especially if you eat or drink either shortly before bedtime.
Train yourself not to clench. During the day, notice if you are pressing your teeth together and work to hold them apart even if your lips are sealed. Putting the tip of your tongue between your front teeth may help.
Talk to a doctor. People with a severe grinding problem may benefit from a temporary prescription for muscle relaxants or even surgery. Just be aware that medical interventions may have unpleasant side effects. Relaxants, for example, can be addictive over time.