Ora-Cleans Chews have an abrasive texture, which help scrub your dog's teeth while he chews.;Ora-Cleans Chews have a blend of the enzymes Lacto Peroxidase and Glucose Oxidase, which help prevent plaque and tartar build up as well as promote clean teeth.;Ora-Cleans Chews are made of beefhide and coated with enzymes that prevent harmful bacteria from building up.