For some people they grind their teeth as they sleep as a result of various stresses throughout the day; this can cause stress on the teeth that will cause them to be displaced. Usually clearing your mind before you go to bed and letting go of those tensions will help, but some people develop a long term habit and a more long term solution is required.
Your teeth are important to you and should be looked after, therefore a way to protect your teeth from grinding as you sleep is to get a night guard from your dentist; also called a bite guard. When you go to get one made, the dentist will make a mould from the shape of your teeth; this is not the most comfortable of procedures, so make sure your day starts stress free, and prepare yourself for this.
When you get your night guard it will usually be clear and will fit to the upper row of your teeth, and should fit in nicely; the problem however is that you wont be used to having this in your mouth, and you may trigger your gag reflex when moving your tongue around the outline of the night guard. If this happens then you will need to keep trying until you get used to it; usually best to practice a few hours before you go to bed and sit down somewhere for a while until it becomes comfortable in your mouth, and then you should be able to sleep.
The next thing to be aware of is the morning routine, as when you take that out of your mouth, it’s bound to have accumulated saliva during the night from your unconscious attempt at grinding. This is really not a problem, and if you have a spare toothbrush that has soft bristles that you can use to clean it; then rinse it off under the tap and sterilise in mouthwash solution momentarily. Then all you need to do after that is to leave it in a small container, or small cup with water during the day; this way it will be ready to rinse off and shake before wearing for bed time.