Most modern cat foods can be associated with the build up of plaque and tartar on cats teeth.
This is even true of many dried kibble or biscuit diets. (When the tooth applies pressure to a hard biscuit, the biscuit can shatter, producing crumbs which mix with saliva and leave a coating of food debris on the teeth.)
Hill’s Prescription t/d is different due to a meshwork of tiny fibres which are formed throughout the kibble.
The kibble itself is less brittle so that the tooth will sink into it before splitting, so mechanically cleaning the sides of the tooth in a way which cannot happen with many traditional hard kibbles. Hill’s t/d might well be the best commercial diet available for keeping cats teeth clean and the mouth healthy….