Tooth whiteners get a charge from COC-based blister-film

Remedent, which produces oral care and cosmetic dentistry products, has created a bright idea to whiten teeth in a peroxide-laden foam sponge. With help from innovative packaging, the products, MetaTray™ and iWhite™ tooth-whitening agents, are sold through dentists and over the counter, respectively. The MetaTray sponge is blister-packed in a film made by Tekni-Plex (www.tekni-films.com), based on COC (cyclic olefin copolymer) from Topas Advanced Polymers' (www.topas.com). Developed on a fast track, the blister-pack incorporates the Tekniflex® COC P15P coextruded film grade, a Topas COC core layer and polypropylene. One of the outer layers is a white, low-density polyethylene laminate, which gives the package a clean look and protects the sponge from light. Sealing the blister is Teknilid® WPSPPE peelable lidding foil, which also contains a peroxide-resistant adhesive. The blister-film's PP layers are inert to peroxide, while the COC core layer provides additional chemical-resistance, a high moisture barrier for extended shelf life and an inherent stiffness that gives the blisters a solid, luxurious feel. Users remove a foam strip from its peelable blister-pack and place it in a dental tray, which holds the strip against the teeth. Peroxide gel in the sponge bleaches tooth enamel discolored by medication, plaque, smoking, food, wear or damage. The bleaching action is fostered by heat and light, and the temperature is elevated about 10 deg C to double the reaction speed, while a blinking light in the tray catalyzes the reaction. The COC moisture-barrier layer ensures an 18-month shelf life for iWhite and a 14-month shelf life for MetaTray. The PP/COC/PP/LDPE film also forms well on standard thermoforming lines and is claimed to have a broad thermal processing range for both forming and sealing.