I have found two things that really help Lexi keep clean teeth. The first is a large beef bone, particularly a knuckle bone as posted before. They are tough and nearly indestructible. Lexi has had hers for a year and a half and it still looks like she has barely touched it. She gnaws on it all the time. However, I do make sure she only has it while I am at home, to make sure nothing breaks off. As far as I can tell she actually doesn't "eat" the bone, but over time her saliva probably breaks it down. I'm guessing that is how it works since she's never been able to even break a piece off. The other item I love to give Lexi is "Gentle-Dental Twists" (They are made by DentaClean, if that helps). They are similar to a rawhide twist, but much easier to digest. Because they have no flavor listed, I sniffed one the first time I gave one to her and to me it smells sort of sweet, but chicken is one of the ingredients. Anyway, Lexi usually finishes one of these off in about 10 minutes, because they are softer than a rawhide, and I have never noticed a softer stool. Hope this helps!!