Keep your smile white with our universal refill kit: use in Spa Dent dual arch comfort fit trays, custom dental trays to whiten or as a nightly toothpaste booster to fight lifestyle stains and maintain a bright smile. PH Neutral, Silica Free, Lactose Free and Gluten Free ingredients that whiten, fight bacteria and remineralize. A must have for anyone with Orthodontics to prevent white spots at adhesion points. - 24 Whitening Treatments - Made with all-natural, vegan ingredients