My last dog never had much issue with tartar, but the dog I have now was recommended to have a professional cleaning a year ago. I couldn't afford it at the time, so I started giving her Greenies and searched for alternative products. I happened to notice these chews about 6 months ago when I was purchasing heartworm preventative from PetCareRx, and bought them. My dog loves them. About a month ago I took her to the vet for her yearly vaccinations, and the vet said her teeth look pretty good. She said in asked what I was doing, I mentioned enzymatc chews, and she knew right away about CET. She said we could look at my dog's teeth again in 6 months and see how she's doing, and whether she would need a cleaning, but to keep up with the CET. I'm optimistic she wont. The only issue with these chews is specific to my dog -- she swallows the whole thing as soon as it's soft enough! -- though I know not all dogs do that, and even though she does, she is not having any issues with digestion. Great product, highly recommended!