A mouthguard club mouthguard is based on a digital 3-D scan of your patient's teeth and is much more accurate than a generic mouthguard that is a boiled piece of plastic loosely formed over teeth. A Mouthguard Club Mouthguard will fit like a glove and offer better protection for your patients than a loose-fitting generic that often falls out leading to no protection.
With regular wear mouthguards typically last one sports season. Your patients should also replace their mouthguard if they get a virus (strep or the flu). Mouthguards, like their toothbrushes, collect bacteria and viruses over time. The only way to eliminate 100% of them is to throw it away and get a new one. Also, anytime their teeth change (eg. they lose a baby tooth or get a new filling or crown) they should get a new scan and order a new mouthguard.