Zorgas t1_jed8wp1 wrote on March 31, 2023 at 4:08 AM

Teeth enamel is permeable, you can see this by people who smoke having yellowed teeth, people who drink sugary drinks having yellowed teeth etc

Visually it's quite amazing how rough the enamel is upon magnification!

Fluoride, being a mineral suspended in water or, in this case, toothpaste, can go into the small gaps and divets in the enamel. It bonds into the little divets and acts like a shield against bacteria and other gunk.

Shark-Whisperer t1_jef7nuh wrote on March 31, 2023 at 4:00 PM

Underneath the enamel surface the dentin layer contains an organized network of tubules that can be clearly seen on micrographs.

Here's a very cool article on the difference between narwhal tusks and human teeth :=} Towards the end it has a figure/photo of the dental tubules. https://biologicalexceptions.blogspot.com/2015/03/the-search-for-unicorn-slightly-off.html