Do cats really need the Vet anesthetized Dental Cleaning and Extractions?

Does a cat really need to have a Vet dental teeth cleaning? It is risky going under the anesthesia, expensive, and some Vets have to do re-dos because they leave bits of the roots in the mouth, like in my story about Merlin my cat who died of cancer. So is long term antibiotics a good solution to gingivitis and serious gum disease in a cat, as opposed to taking your cat to a risky dental cleaning?

Should cats really get the anesthetized teeth cleaning? My cat Merlin lost all of his front pre-molars and he stopped eating, and he had a scraping sound when he was eating. I took him in for root pre-molar extractions. The VET did a blood test and okay’d him for Dental. She did a lousy job at the extractions. On one pre-molar root, she left it with sharp edged jagged pieces I could see. Later, I took my cat to a different Vet, and he advised me to take him to emergency immediately. It turned out my cat had cancer. He never should have been okay’d for dental. The second Vet took one look at my cat and knew he was gravely ill. The Dental Vet probably did as well, but she was greedy for the money. The ER Pet Hospital Dr. told me the anesthesia put my cat into shock since he had cancer. Not too long later, about a few weeks after the dental, my cat died of cancer. He did have pearly white teeth (and still that jagged sharp left in tooth by the dental vet, whom also gave him ringworm, a limping leg, clipped his nails past the pink area, and put a sign on his cage saying he was aggressive) and clean gums, and so he was cremated and I have his ashes in a cedar box with a nameplate and a lock. Now my other adult cat seems to have possibly lost an upper premolar. I have been brushing his teeth. I am so afraid of taking him to have dental cleaning. He is eating fine and has a very healthy appetite and drinks bottled water I feed him over a water bowl. He is so beautiful, I think he is a blonde Ragamuffin. The first time I started brushing his teeth there was blood on the toothbrush, (a tiny cat brush with cat toothpaste), then after that, no more blood when I would brush his teeth. I just cannot reach all of his teeth?