Petsmiles proprietary formula Calprox is clinically proven to inhibit plaque and tartar buildup, while whitening teeth by gently dissolving the protein pellicle. The protein pellicle is the thin bio-film that forms on the surface of the teeth, to which plaque, bacteria, and stains adhere. Removing the pellicle leaves your pets teeth cleaner and whiter while improving gum health and providing kissable fresh breath.