- they have multiple generations of teeth that form throughout their lives,

- Each new tooth develops from a group of cells called the dental lamina.

Humans cannot regenerate teeth because:

- we have only two sets of teeth: baby teeth and adult teeth,

- Once the adult teeth are lost, they cannot be replaced, because we lack the dental lamina which is the tissue that forms new teeth.

But there are ongoing research and advancements that explore the potential for tooth regeneration in humans:

- Scientists are investigating ways to stimulate the growth of new teeth by activating dormant dental lamina cells or by using stem cells.

- Tissue engineering approaches combine scaffolds, growth factors, and stem cells to create tooth-like structures.

- Gene therapy aims to manipulate the expression of genes involved in tooth development.

These approaches hold promise, but challenges such as vascularization, innervation, and integration with the jaw bone need to be overcome.

So, while humans currently can't regrow teeth like fish, future developments in regenerative dentistry may bring us closer to this possibility.