Night guards (also called bite splints, bite planes, or occlusal splints) are removable dental appliances carefully molded to fit the upper or lower arches of teeth.
They are used to protect tooth and restoration surfaces, manage mandibular (jaw) dysfunction, and stabilize occlusion or create space prior to restoration procedures. People prone to nocturnal bruxism, or nighttime clenching or grinding, should routinely wear occlusal splints at night.
Night guards are typically made of a heat-cured acrylic resin. Soft acrylic or light cured composite, or vinyl splints may be made more quickly and cheaply, but are not as durable, and are more commonly made for short-term use. Soft splints are also used for children, because normal growth changes the fit of hard splints. Some guards require heating under warm running water prior to insertion and improve fit as they cool.
They generally cover all the teeth of the upper or lower arch, but partial coverage is sometimes used. Maxillary (upper) splints are more common, although various situations favor mandibular (lower) splints.