Do you give chew bones of any kind (tendons, bully sticks, raw meaty bones, ribs, Himalayan chews, cow hoof, etc)? There are also oral gels and oral sprays that you can apply nightly. There’s even a seaweed that you can add to feeds such as ProDen Plaque Off or other brand. My dogs will chew on their cow hoof for two hours after they’ve eaten the tripe out of it (frozen tripe-stuffed cow hoof) and they really love gnawing on beef ribs. The Himalayan chews are really tough as well and last.