[SalmoShalazar]

I’m in the same boat. I’ve eaten a lot of junk in my life (standard North American trash diet), and have never had a cavity or any serious dental issue in my life. I also get a cleaning every 6 months at the dentist. I’d be shocked if the likelihood of developing a cavity didn’t have a large genetic component.

[monocasa]

My guess is that it's mainly the composition of your mouth's microbiome. Some bacteria really like creating acid that eats away at enamel. Some don't. Whichever happens to have a foothold in your mouth (which probably has a very inherited component) is probably the determining factor in tooth decay.

[bjornsteffanson]

I'm 36, and I've had 32 cavities filled in my lifetime. I can't stand the procedure every time, and it's been heartbreaking for me not to be able to pinpoint why I've had so many cavities. I'm vegetarian, and I don't drink soda or alcohol. I brush regularly but should probably floss more. I do drink a lot of coffee and a lot of water. I completely avoid any candy and processed sugar (except for the occasional bit of something sweet in a restaurant dessert once or twice a year). I also eat a lot of acidic fruits and vegetables like tomatoes, lemons, limes, and pineapples.

Most were in my early teens (I had eight filled at once one time) so I was convinced it was the dentist racketeering and my parents wouldn't let me out of getting them filled. I should note my parents have a similar diet and a similar amount of major dental work. The handful of cavities I've had in adulthood have been major blows to my mental health.

[dharma1]

This feels intuitively right, but you would think changes in diet can affect this too (if caries causing bacteria mainly feed on sugar).

There has been some research into oral probiotics like K12 and M18 but I’m curious how effective these really are.

[User23]

I've sometimes wondered if dental hygiene may actually be counterproductive by killing harmless or even beneficial bacteria and leaving a niche open for harmful ones.

[asdff]

I think the biggest components is exactly what the dentist tells us: brushing and flossing.