Disclaimer: I’m a psych nurse not a dental professional, but I’m commenting because my patients are a high-risk demographic for dental disease for a bunch of different reasons including poverty, decreased self-care, and medication side effects (particularly dry mouth and teeth grinding but I’ll get to that) so these are the tips I give to my patients.
Brushing and flossing, obvs. I’m not going to elaborate on this one too much because there’s plenty of actual experts on this that you can find that will explain the ideal techniques much better than I ever could.
Chewing gum and tic tacs / mints that have xylitol (and NO real sugar) in them because xylitol is particularly known to stimulate your salivary glands. Normally we associate increased moisture with bacterial growth, but your saliva is actually slightly antimicrobial and an important part of your oral immune system, so the dryer your mouth is the more hospitable it actually is to bacteria. So while you don’t want to be drooling everywhere, you do want to make sure your mouth is nice and wet most of the time. Both stimulant medications (often given for ADHD) and antidepressants can cause dry mouth.
BUT if you’re straight up eating the xylitol it can have an osmotic laxative effect (pulls water into your gut and makes your shit watery, pretty much all fake sugars do that) so you definitely want to select a xylitol product you can suck on or chew on for an extended period (as opposed to just eating and immediately swallowing like gummy bears or something) to maximize salivary stimulation with the least laxative effect.
It also helps to practice breathing through your nose (which has the added benefit of reducing anxiety), and they even make little sticker thingies to help your mouth stay shut while you sleep. Speaking of which, if you grind your teeth, you’ll also want to wear a mouthguard while you sleep. Grinding your teeth can be caused by a lot of different things but the two biggest things I see are anxiety and certain medications (particularly stimulants and antipsychotics).
And lastly this is kind of anecdotal but the biggest thing that helped my oral hygiene was having to mask at work during the pandemic because I could smell my breath all the time. I had never really been good about routine oral hygiene before that, but I started having to brush my teeth before I left the house every single day to be able to tolerate wearing a mask, and for a while I was even brushing my teeth after lunch, but eventually to save time I switched to mouthwash then I’d head back out on the floor while chewing a sugar free xylitol gum behind my mask.