Without teeth, tongues would slither out of mouths and go on to lead unfulfilling lives catching raindrops and licking strangers' faces. Keep a stir-crazy taste muscle contained in a gleaming cage with today's Groupon: for $98, you get a custom take-home teeth-whitening kit at Dental Associates of Summerville (a $295 value).

The friendly staff, modern furnishings and equipment, and TVs found in every exam room at Dental Associates of Summerville serve as antidotes to the notion that dentistry must be unpleasant. Groupon purchasers will come in to be custom fit for an Opalescence take-home teeth-whitening kit, which includes gel and a bleaching tray customized to accommodate each tooth's shape and idiosyncratic sense of humor. Patients will notice brighter smiles and an increased number of wind-blown kisses from passing strangers in about a week. Newly whitened mouth pearls receive an extra boost from the potassium fluoride formulated into the gel, which strengthens enamel and acts as a burly nightclub bouncer for encroaching cavities.