Lori i have not heard this before, it is news to me, maybe others can enlighten you on the subject, my cat Ash had his dental at 14,but it was then that they found he already had CRF,(Chronic renal failure) did they do pre-blood tests before the dental, because they should have in a cat that old, i would go get some done to make sure he does not have anything going on that you don't know about.

One thing i would strongly advise you on is to get your cats dental done, just make sure they do the blood tests first to see how healthy your cat is, if it needs hydration before the dental, and what kind of anesthetic it needs, if you leave your cats teeth at that age especially or any age for too long they will develop CRF,cats can get that from old age too, but the infections in the mouth gradually go to their organs, so don't be put off doing it please,just take all the precautions necessary as advised by your vet.