The unique Petrodex Dental Gel preloaded in the cartridge contains the active ingredient Chlorhexidine which has been shown to kill the bacteria that forms plaque and leads to periodontal disease. Using the right amount of gel is as simple as a few clicks. The Tooth-Hugger brush has a unique patented arrangement of bumps, nubs and ridges that provide gentle cleaning action that reaches all exposed surfaces of your pet’s teeth.