Mine have beautiful, pearly white teeth. My toy poodle has such a tiny mouth that she didn't have room for all her permanent teeth to grow in and had to have back molars removed at 9 months to make room in her mouth. Vet said she would likely need frequent dentals just because her mouth was so small it would be hard to keep the teeth clean.
They eat Primal frozen raw food. I know it's the bones in raw feeding that are supposed to keep the teeth cleaner but I think the raw food makes a difference too.
We use these treats - Tropican dental chews - they get one every evening.
Amazon
I'm also pretty good at daily brushing with Tropiclean gel, and if I'm going to be away and can't for some reason I use the Tropiclean water additive.
It's been two years since the poodle with the tiny mouth has had a dental and she doesn't have a speck of tartar.
Diana