Whitening your teeth at home often involves using a custom fitted mouth guard into which a whitening solution is placed. These custom fitted mouth guards will help protect your gums from irritation that occurs while using ill-fitted, over-the-counter whitening mouth pieces. After the solution is placed in the mouth guard, it is placed over the teeth and left on for a few hours or overnight depending on the type of whitening solution. Ask Washington Township Dental Associates, PA if home whitening is right for you.