Why don over-the-counter systems offer a 25% concentration of whitener?
One reason is shelf life. Many of the whitening products take months to make to the shelves and by offering a lower concentration of active ingredient they increase the shelf life to, in some cases, several years. It is common for a consumer to buy a product that is over a year old. Twilight Teeth has an 18-month shelf life and guarantees freshness to the vendor so you know you are using the strongest and freshest teeth whitening system available today. Another reason is how they apply the teeth whitening gel. Most systems are VERY crude in their design. They require messy amount of gel to be placed in a tray and then squished into place only to ooze gel throughout the mouth and all over the gums and soft tissue. Even the expensive molded teeth trays made by a dentist can ooze undesired amounts of gel if the amount is too great or the customer bites down too hard on the apparatus. Most teeth whitener manufacturers keep their active ingredient down to a minimum (in some cases as little
