Yellow teeth indicate an addiction to smoking cigarettes, drinking coffee, or swishing with butter. Undo unsightly dairy habits with today's Groupon: for $79, you get an in-office NuYu Teeth Whitening at Bella Tula Salon, Classic Beauty Concepts, or Serenity Salon (a $199 value).

Specialized technicians garnish grins in pearly-white hues during NuYu teeth-whitening sessions, which can brighten fangs 2–8 shades or more on the Vita Bleachguide. Clients clamp down on prefilled mouth trays and recline in comfort as a cold-blue LED light activates the hydrogen-peroxide solution, sending revved-up molecules throughout the mouth's toothy landscapes and dusty attics. The specially designed NuYu trays encompass breathing vents, cushioned overhangs to protect lips, and built-in light magnification, which accelerates the whitening process to a succinct 30-minutes. Newly brightened smiles should avoid dark-colored food and beverages for 24 hours following the treatment to prevent re-staining of porous enamel. Results can last up to a year depending on diet and amount of time spent shouting at unpredictable ballpoint pens.

Upon redemption, Groupon customers will receive a $10 credit good toward future teeth-whitening products or services.