I hope Corny snaps back into shape for you. As for your feline friend, cats handle dentals really well if that is what is recommended (usually, of course - it's still a surgery, so make sure you do blood work to make sure liver and kidneys are healthy enough for anesthesia). Mine; she's 8; just had one done. She had a resorption lesion of two of her top incisors and a very mild one on her upper left canine tooth. The two incisors were removed, the canine cleaned, two weeks of antibiotics and she's fine. The dental itself took 23 min from intubantion to recovery. She will probably loose the canine in a year or two, but for now she's good. (I however handled it badly, took her in on a day that I didn't work, waited by the phone until she was done and stayed up all night counting respirations like a crazy person)
I brush her teeth and have her on a dental supplement daily, it really does help keep the tarter down, if your cat will tolerate it lol.