Formula now more environmentally friendly per new FDA regulations! These effervescent cleaning tablets are safe for cleaning clear Essix retainers and clear Invisalign orthodontic aligners, plastic and wire Hawley retainers and appliances, mouthguards, nightguards, bruxism appliances, Valplast Partials, and TMJ splints. It is a great cleaner that gets rid of odors, dissolves light plaque buildup, and prevents new plaque buildup! It keeps your retainer bright and shiny. You are left with clean, fresh-smelling appliances! (Please note, if your dental appliance has heavy old plaque buildup, Retainer Brite will not remove heavy plaque buildup. The new formulation (per FDA regulations) changes only one minor ingredient and does not affect the way Retainer Brite cleans, smells, or "tastes" on your dental appliance. Depending on the water in your municipality, the formula might not change from blue to clear after 15 minutes, but it does not affect the way that Retainer Brite cleans your dental appliance. Retainer Brite is specially formulated with gentle cleaning agents and the proper PH that will not yellow or harshly affect removable plastic appliances (this is how it differs from denture tablets). It's the perfect solution for clear plastic retainers and aligners -- no more scratches, yellowing, or cloudy devices! Retainer Brite keeps them crystal clear and good as new, dissolving old plaque buildup and preventing new plaque buildup. Retainer Brite keeps them crystal clear and good as new! *Kills 99% of common odor-causing bacteria including: Staph aureus, E. coli, P. aeruginosa and F. nucleatum. Data on file. Independent 2016 U.S. lab testing (ASTM method E2315-03).