The invention relates to a dental splint with a U-shaped base and wall-shaped reinforcements on the tongue and lip sides, said reinforcements forming channels, and to a method for the production of said dental splint. Said splint consists of different plastics of different degrees of hardness. The dental splint is thus flexible, offers a high degree of wearing comfort, and causes an increase in power and endurance in the wearer during athletic activities. An upper jaw dental splint can also be used as a mouth guard in contact sports with an additional reinforcement. Said dental splint for the upper jaw can be designed such that a free space is formed in the front teeth region after inserting the dental splint and clenching the teeth, whereby additional air for breathing can reach the oral cavity.