Unlike over-the-counter guards, A truly custom-fitted guard ensures a snug fit without falling out or rubbing gums during sleep. Custom-fitted night guards have been offered by dentists for decades as a treatment for both minor and severe teeth grinding/clenching. The trays are generally 2-3mm in thickness and are relatively soft yet durable. This allows a cushion on the bite surface thus eliminating tooth on tooth grinding as well as reducing jaw and tooth soreness due to clenching.