So ScienceNOW reported on a study that showed some interesting differences and similarities between shark teeth and our teeth. From the study conclusion:
"Although fluoroapatite has a higher hardness compared to hydroxyapatite, the shark teeth enameloid (fluoroapatite) was not harder than the enamel of human teeth (hydroxyapatite)."
"The fact that sharks use fluoroapatite as tooth biomineral instead of hydroxyapatite which is used by mammals does not lead by a higher hardness of the shark teeth and must have a different, but hitherto unknown, reason."
They also show that the mineral fluoroapatite is much harder than both kinds of tooth but more brittle (in correspondance with what we already knew).
So my question is this: does this mean that we are better off with hydroxyapatite enamal than fluoroapatite? There's fluor in toothpaste (sometimes in drinking water) to give us fluoroapatite enamal but is this not preferable when we aren't eating a diet with lots of sugar?
I'm so confused.
UPDATE: Okay, according to Wiki-p the fluoridation status of teeth doesn't mean anything for caries but fluoride in saliva and plaque do. And the ability of fluoride to decrease tooth decay was first discovered in areas where the natural fluoride content of the water was high.