My eldest daughter just got back from an $800 dental appointment. She had four (!) cavities to be filled and ended up needing two stainless steel caps as well as a generous dose of nitrous oxide to keep her from wigging out like she did on the dentist's first attempt at fixing the teeth.
We brush her sisters' teeth the exact same way and duration, but they have been cavity free.
It seems my eldest inherited her Dad's weak enamel and my middle girl has her momma's teeth, which are strong as a horse's. I can eat candy and sugary drinks and I never floss and the dentist always raves about my smile, while my poor hubby is the most diligent brusher I have ever met and he has cavities all over the place.
Life's not fair, I guess. (He also has buns of steel while mine are a party that all the cottage cheese in the world got invited to, so maybe it all balances out. That being said, I would take rotten teeth over a jiggly rear any day.)
Regardless, we have definitely become more diligent about our kids' oral care and have added flossing to the regime and are making sure the sugar bugs die a timely death before wreaking havoc in young mouths.
Are you hardcore tooth-brushing nazis? Or do you figure that since they're just baby teeth, they may as well rot in your kid's face? Have your kids had cavities despite your best efforts? Anyone want to start a support group for parents of cavity-ridden kids? It sure makes you feel like you SUCK at the whole "keeping your child cared for" deal.