A night guard for teeth is a protective device worn while sleeping to prevent damage from teeth grinding (bruxism) or clenching. It acts as a cushion between the upper and lower teeth, reducing pressure on the jaw and preventing wear on tooth enamel. Night guards can be custom-made by a dentist for a perfect fit, offering better comfort and protection than over-the-counter options. They are essential for maintaining dental health and avoiding long-term issues like tooth fractures or jaw pain caused by grinding.