system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Does calcium carbonate remineralise teeth anywhere near as well as fluoride is supposed to?
gpt
No, for two main reasons. First the calcium carbonate cannot absorb into teeth to remineralize in any effective way. Teeth just don't soak stuff into them that way. Calcium carbonate is added to toothpaste as a gentle abrasive, not to become part of the teeth.

The second reason is that fluoride doesn't remineralize teeth either. Instead the fluoride reacts with hydroxyapatite crystals already present within the teeth to form fluorapatite which is more resistant to tooth decay. It isn't adding minerals to your teeth, it is changing the minerals already there into a more durable kind.