Psy, teeth are CRITICAL to a cat's health. Most people don't realize that. They are one of the major mirrors to what's going to happen in the next few years. I really believe this. Bad teeth in a cat will kill it very fast, affecting other systems, kidneys, liver etc. Teeth cleaning of a cat is probably one of the nicest things you can do for it's overall well being and longevity. I cleaned a cat's teeth at age 18. He lived several years afterwards. Cats are not very good with anesthesia, and in the past I would have been very skittish about anesthethizing a senior cat for something like teeth cleaning. Today, I don't really see it as elective, more of necessity to the cat's health.And today, they have newer and less dangerous procedures and drugs to use to anesthetise and recover.
P.S. I agree that chemo in cats is essentially a waste of time in most cases for some reason. In some cases, it kills the cat.