Chewing helps remove plaque and tartar for cleaner teeth. Rigid outside. Chewy inside. The line of Hartz Dental Denti-Chew consists of two unique textures combined into one palatable treat that is designed to satisfy dog's urge to chew. Each chew starts with a very rigid outer layer that encourages chewing which helps to remove plaque and tartar for cleaner teeth and freshen breath. The softer center is made from a delicious filling which your dog is sure to enjoy. Chewing helps remove plaque and tartar for cleaner teeth. Chewing helps promote clean, fresh breath.