My cats get permium dry food only except for special circumstances. One cat has perfect teeth, the other has big problems with his teeth (he gets little holes in them down by the base). They were fed canned food up until age 5 and both of them had bad teeth as well as some other problems. So I can only conclude that one cat genetically has terrible teeth, and the other's teeth do very well on a dry-only diet.
I feed dry food only for a variety of reasons. 1) Their litterbox is much more managable when they eat dry; 2) They're horrible beggars when fed canned food and seem hungry all the time; 3) Their breath is HORRIBLE when they eat canned food. It got so bad at one point that I took them to the vet, I was worried they had an infection or something else wrong; 4) They go through a lot of canned food, which creates a lot of waste and trips to the pet food store.
They seem happy with their dry food, they eat it with gusto and drink plenty of water. Their kidneys are doing great, even though they're both old boys at 15.