If toe nail is slammed will it grow back again?

Yes: A toenail that is traumatized will grow back, perhaps at a slower rate. However, the appearance of the nail may be altered if the matrix (the area that determines the growth of nail) has been affected.

Most likely yes: When we traumatize a toenail, many times it will fall off. Our body is amazing and usually grows one back. A toenail will take about a year to grow back. The unknown is, how will it look. May times it grows back thicker or deformed.