We did not notice Filou had a tartar problem until he lost one of his teeth at the age of 4 (sorry he never told us and we had never experienced that with a cat). Now his and Tigris' teeth are yearly checked and have been cleaned 2 times. They need to be anesthesized then so it is quite a procedure. Sometimes I think it is the breed. I have a friend whose Abyssinian lost 3 teeth at an age of 2 years.
The next question is what food they should eat. I feed wet food during day time and dry food in the evening. Just dry food w.ould be better for the teeth but how about the water supply. Both of them do not drink very much although they have fresh water and even a cat fountain.
I would be glad to hear about your experiences.
P.S. I know that there is cat toothpaste and toothbrushes. I have asked Filou about it and he said "No way"