Try giving your kids xylitol candies/mints (available at amazon and many health food stores), initially after every meal - you can probably reduce the frequency/amount later.
There are xylitol chewing gum, but I've read articles about kids dislike for chewing gum these days - so candies/mints may be more palatable.
search for "xylitol tooth decay" for explanation about its effects.
Excerpts from one such link: https://bellharbourdental.com/cavities/xylitol-reverse-tooth...
Mutans streptococci (MS or S. mutans) are a bacterium in plaque and saliva that are major contributors to tooth decay and oral disease.
...xylitol reduces the levels of MS in the mouth. It essentially starves the MS bacterium by not providing any energy to it when metabolized. Since xylitol is a non-nutritive sugar the MS bacteria spend energy to metabolize it and in return receive no energy gain from it. It’s a sunken cost and the S. mutans cannot keep growing. This reduces the population of S. mutans and impedes the ability of plaque and bacteria to adhere to our teeth. It also decreases the amount of lactic acid present in our mouth, making our teeth less vulnerable to decay. Curiously xylitol does all of this without affecting the other beneficial, or overall, flora of our mouths.
Another amazing find has been that when a mother of a newborn uses xylitol, that child’s teeth prove to be more resilient against cavities as they develop. Children have a dramatically lower risk of cavities when their mothers use xylitol starting 3-6 months after childbirth and continue using it until all their baby teeth are formed around the age of 2.
Xylitol comes in many forms but the most common delivery method is through chewing gum. Chewing xylitol gum for 3 weeks or more provides not only short but also long-term reductions in S. mutans levels! Even just the action of chewing the gum helps to rinse away lactic acids.
In order to be effective against bacteria the optimal intake levels are at least 6-10g of xylitol per day. Xylitol gums range from having .75g – 1g of xylitol per piece. So make sure to check the gum that you’re buying to make sure it contains closer to the ~1g/piece mark. In order to reach those levels you will need to chew more than one piece at a time a few times a day. After meals is a great routine to get into, but make sure to wait for at least 20 minutes after eating food before chewing xylitol gum.