Sports mouthpieces, also called mouth guards, are worn during contact sports activities. They reduce injury to the wearer's teeth and soft facial tissues and prevent some concussions, according to Family Gentle Dental Care in Nebraska. Have your dentist custom-make a mouthpiece for you or purchase a boil-and bite-mouthpiece from a sports store and mold your own. The American Dental Association considers custom-made mouthpieces most effective, but states boil-and-bite mouthpieces "can be effective if they fit well, are worn properly and stay in place."
Boil a small pot of water.
Fill a small bowl with cold tap water, while you wait for the pot of water to boil.
Grasp the mouthpiece by the strap. Dip the body of the mouthpiece in the boiling water while keeping hold of the strap. Hold the mouthpiece in the water for 30 seconds or as directed by the manufacturer.
Pull the mouthpiece out of the boiling water after the 30 seconds or as directed by manufacturer and immediately place it in the bowl of cold water. Hold the mouthpiece in the cold water for the amount of time directed by the manufacturer, which is usually one to three seconds.
Insert the mouthpiece into your mouth immediately after removing it from the cold water. Work quickly to get the mouthpiece into the correct position before the material hardens. Place the mouthpiece fully into your mouth, so that your back teeth are covered. Adjust the mouthpiece, so your teeth sit inside the troughs. Use your fingers, if necessary, to adjust the mouthpiece into position. Bite down on the mouthpiece firmly, but not hard, to make an imprint of your teeth.
Remove the mouthpiece from your mouth and place it back in the boiling water for two seconds while keeping hold of the strap.
Pull the mouthpiece out of the boiling water and give it a quick shake to remove the excess water. Quickly put the mouthpiece back into your mouth, adjust it so that it sits all the way into your mouth and covers your back teeth and bite down once again. Place your forefinger and thumb in your mouth, while continuing to bite down on the mouthpiece, and press down the mouthpiece against all of your teeth.
Remove the mouthpiece from your mouth and hold it under running tap water for 10 seconds.
Submerse the mouthpiece in the bowl of cold water and leave it to cool and set for two minutes.
Remove the set mouthpiece from the cold water. Place it in your mouth again and take note of any sharp or uncomfortable areas. Remove the mouthpiece from your mouth and trim off sharp or uncomfortable areas, using a pair of scissors.