Removing a tooth is sometimes suggested when the tooth is not restorable, an infection has resulted, a trauma has occurred or due to crowding/guiding the eruption of permanent teeth. On occasion, it is important to preserve the space for an erupting permanent tooth. The pediatric dentist will then suggest a space maintainer which is an appliance made of metal and/or acrylic. It is typically cemented in the mouth and only removed when it is no longer needed to save the space for the permanent tooth.