Smiling is an easy way to let someone know you mean no harm, much like saying hello with a firm handshake or surrendering your medieval weaponry. Give friendly grins a pristine makeover with today’s Groupon: for $89, you get a custom-fit take-home teeth-whitening kit at Whitesmiles Teeth Whitening Centers (up to a $350 value).

Patrons can brighten their pearly whites in the comfort of their own abodes with Whitesmiles Teeth Whitening Centers' at-home whitening kits. After the initial consultation and tray fitting with a technician with custom impressions made of each client's teeth, clients head home with a custom-fit teeth-whitening kit ready to erase stains from drinking coffee, smoking cigarettes, or chewing on permanent markers. With a two-week supply of Opalescence or Nite White whitening gels, clients fill their personal vacuum-sealed trays and then sink in top and bottom chompers, leaving the trays in overnight to transform grins into room-illuminating night-lights or wearing them throughout daily tasks, such as mowing the lawn or feeding the lawn gnomes. After the whitening process, patrons can compare their before-and-after photos with a sense of pride and further marvel at a shade analysis, which tracks teeth as they become 8–10 shades brighter. Though Whitesmiles Teeth Whitening Centers sometimes features a discounted price online, this Groupon still offers the best deal available.