Taking care of teeth, is more better? ?

I took my 2 daughters to the dentist the other day, and made a strange discovery. One of them has always been fussy about her teeth. She brushes every morning when she wakes up, after she eats lunch when she is not in school, after dinner, and at bed time. She has done this since she was 2 years old. She also never eats sweets or sugary things, does not drink soda at all. I was told that she had 7 cavities. My other daughter hates brushing her teeth, She does it when she gets up in the morning when she feels like it. And that is maybe a couple times a week. She drinks soda, and loves candy. Her teeth are perfect. Not one cavity at all. After I got thinking about it, I realized that I have seen this a million times. When I was a kid I never brushed my teeth. I hated doing it, and I just wouldnt. By the time I was 13, I had only been to the dentist 2 times, and only 3 more since then. Another strange thing, I am a smoker, drink Diet Pepsi like its water, and a lot of the time I could pretty much live off sweets. Even now, as an adult, I admit to not taking care of them like I should. Quick brush in the morning, and gum chewing as needed. My grandmother is a teeth-cleaning freak. Brushes everyday, 3 times a day, uses mouth wash, flosses twice a day, has never smoked, only chews sugar-free gums, gets a cleaning every 6 months, does not like sweets, and does not drink any kind of soda except for ginger ale occasionally. My grandmothers teeth are filled with fillings. She has had all kinds of dental work done. But I have perfect teeth. Not one cavity or anything. So my conclusion to all this was that people who take great care of their teeth end up with worse problems that ones who dont. Has anyone else noticed this?
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I am like your daughter who brushes often and does not eat sugary foods or drinks-I have never had a cavity. Dentists say that if you get through your teenage years without one, you probably never will get one. I was placed on a lot of vitamins that help bones when I was a baby-think if perhaps you gave them anything different as babies? There may be a case of over brushing. I once had a friend who was obsessed with teeth cleaning that she left the toothpaste on her teeth for a half hour all th etime-She did not know that tooth paste will actually EAT away at the teeth and cause cavities. You just can't leave it there. Teeth are in essence, bones..maybe hers are weaker and needs more vitamins. You may also want to reconsider saying that she never eats any sugars- is she eating cereals? most are packed with sugars-raisin bran has buckets of sugar on one raisin...etc.. juice is like drinking bottles of sugar too nowadays. You've also mentioned what she doesnt eat but neglected to reassure that she does eat the right foods... Is she eating enough vegetables that help bones? Boiled foods often soak out nutrition, steamed or raw are best. Any milk? etc..
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