I use Healthy Mouth as an additive.
https://www.healthymouth.com/dogs/dogs It is not cheap but cheaper than loosing teeth I figure. Buster will be up for his first 1 year check up soon so I will be interested to hear what his dentist says. They initially recommended this when he had to have his retained baby canine's removed. I like it because all the ingredients are natural. I fill up a bottle with the additive and water and fill his bowls from that. From their site.
Recommended by leading board certified veterinary dentists, dog::ESSENTIAL healthymouth™ is the first dental water additive to receive the VOHC® Seal of Acceptance for plaque control in dogs. Its patented formula, free of synthetic or artificial ingredients, is clinically proven to reduce plaque by a remarkable > 71% in dogs. Safe, highly palatable formula for your dog and pre-dosed packets for you makes dental care a win-win!
I also brush with the CET toothpaste and use their chews.