All night guards should be replaced over time. The life of your SmartGuard Night Guard dependson how long and how often you grind your teeth and the force of your teeth grinding. On average,each night guard should last approximately six month or to over a year. As long as you clean theSmartGuard regularly with denture cleaner, and keep it stored in water when not in use, you shouldhave no problem keeping your SmartGuard for a couple of years.