Without bright teeth to serve as exit lights, exhaled breath might lose its way and instead escape through the gills hidden somewhere on every human body. Keep lapses in evolution from being revealed with today's Groupon for teeth-whitening services at Smile Bright Teeth Whitening, which has four locations in Alpharetta, Atlanta, and Marietta. Choose between the following options:

• For $59, you get a 60-minute in-office teeth whitening (a $249 value).
• For $38, you get professional at-home teeth-whitening kits (a $99 value).

Smile Bright Teeth Whitening offers a fast way to brighten a chagrinned grin without damaging teeth and gums. The in-office process begins with the application of a hydrogen-peroxide gel using a mouthpiece for the upper and lower chompers, followed by exposure to an expediting LED light, and then a reveal akin to the original discovery of fire in the mouth of a gloomy, prehistoric cave. The home-whitening kit comes with gel for eight 40-minute treatments, as well as a mouthpiece, 10 cubic centimeters of professional whitening gel, and an LED light and a sock puppet of a dentist to fully recreate the office experience while out of the office. Each treatment removes roughly the equivalent of three to five years of stains from teeth, and two treatments can remove up to twice that amount. Additional at-home gel refills are available for purchase through the Smile Bright website.