New. Clinically proven to whiten your teeth by 3 shades, thanks to its unique, natural baking soda formula. New Arm & Hammer Advanced Whitening is clinically proven to whiten your teeth by 3 shades. The baking soda particles dissolve to gently clean away both surface & deep stains, whilst neutralising odour-causing compounds for long-lasting fresh breath protection. The advanced micropolishers safely polish to leave your teeth brilliant white, with that fresh from the dentist feeling of clean.