Cavities, like loyal dogs, mustard stains, and live-at-home adult offspring, never leave without strong reproof. Send a clear signal with today’s Groupon: for $49, you get laser cavity-detection, x-rays, a fluoride varnish treatment, and four sealants at Arrowhead Dental Professionals in Glendale (a $365 value).

Led by the husband-and-wife duo of Dr. Scott Cairns and Dr. Christina Cairns, the Arrowhead Dental staff cleans and polishes smiles to pearly perfection to ensure teeth don't fall prey to beauty-marring dental disease. A highly trained staff member examines teeth with a sophisticated laser detector to illuminate lesions on each tooth’s surface, enabling dentists to oust potential cavities before they unpack all their family photos. Then, teeth witness the unparalleled sleuthing skills of the bite-wing x-rays, which hunt down cavities lying in between teeth. Staff members apply a layer of fluoride varnish with a miniature paintbrush to seal out cavities, plaque, and migrating taste buds from delicate teeth. Finally, future cavities get the boot with the application of tiny plastic sealants to the chewing grooves of four lucky back teeth, preventing food from getting stuck in fissures and slowly wearing them down into full-blown canyons. Sealants protect crevices of tooth-troughs, so that toothbrush bristles can easily reach every last drop of plaque, acids, and long-forgotten letters from love-struck tooth fairies.