The number of teeth a shark has depends on the species of shark. For example, the great white shark has about 50 teeth in its mouth. But the amazing thing about sharks is that they can replace damaged and lost teeth very easily. Below the teeth they have in their mouths, there are several rows of new teeth waiting to replace the old ones. It can take anywhere between a day to a few months to replace the old tooth. So, amazingly, a shark can go through about 30,000 to 50,000 teeth over the span of its life.