Hi. My Bella went through this process a couple of months ago and I know exactly what you mean. The 3rd year was when I noticed a decline in her oral health and had to clean her teeth every single year which scared me to death.
My suggestion to you would be, after this process start brushing her teeth every single day! I have been doing it since two months ago and now her teeth are white still and never bleed.
Good luck!
P.S- I use this kit and she loves it. It's just a random website that I pulled quickly so you can see a picture.
C.E.T. Oral Hygiene Kit for Cats | HealthyPets.com