There are two basic types of splints that work, however they can be either firm or soft and can cover all of the teeth or perhaps just a few of them. They are:
Repositioning splints are made to fix biting occlusion. Using, these splints are worn 24 hours a day.
Wearing stabilisation splints will stop you from clenching and grinding your teeth. These splints normally only need to be worn at night and cover all of the teeth