Both types are designed to protect your teeth. However, each does so in different ways. Mouthguards are worn by athletes to protect their teeth during sports events, especially contact matches. They are thicker than nightguards but softer. They are designed to withstand impact and shocks. The American Dental Association recommends wearing a mouthguard when playing contact sports to reduce oral injuries. Nightguards are worn while you sleep and are made from a different material than mouth guards. They are thinner to help you sleep comfortably. Their purpose is to protect your teeth if you grind them at night.