The short answer is… there is no short answer. Toothpaste has a long history going back to ancient Egypt. The stuff that we brush with today is completely different from what ancient Egyptians were using... and that is probably a good thing!
Early toothpaste could be made of lots of different ingredients. The Egyptians used a mixture of things like eggshells, oxen hooves and myrrh ground into powder. Different civilizations used oyster shells, bark, ginseng, cinnamon and even charcoal. Aside from cleaning teeth, it's likely these recipes also caused bleeding gums – ouch!
Fast forward thousands of years. In the 1800s, soap was added to tooth powders for that extra squeaky-clean feeling. Back then, it was sold in small tins. You can still get powdered toothpaste today, though it's not easy to find. It took about another century for American dentist Washington Sheffield to come up with a handy (toothy?) idea. He put his tooth cream formula in a tube, like the ones we use today. But it was still missing one key ingredient. Can you guess what it is?
If you said fluoride, you're right! Fluoride is a mineral and the worst enemy of cavities. Scientists discovered that it can help prevent tooth decay. Since the 1950s, fluoride toothpaste has been available in stores. Two chemists named William Nebergall and Joseph Muhler are recognized in the National Inventors Hall of Fame. Their research led to the creation of modern toothpaste. Swedish dentist Yngve Ericsson is also known for his work developing fluoride toothpaste.
Then came another problem for scientists to solve. How would astronauts brush their teeth in space? In zero gravity, you can't just go around spitting toothpaste and water wherever you like. "Space toothpaste" can be safely swallowed and works without water. It has been in use since the 1960s, thanks to Dr. Ira L. Shannon. This doesn't mean you can't use regular toothpaste while orbiting Earth. Check out this video of Canadian astronaut Chris Hadfield brushing his teeth in space!
There are many toothpaste brands to choose from today. Some do not add fluoride. Some claim to whiten your teeth or freshen your breath. You can check the ingredients on your tube at home. Don't see eggshells or burned bread on the list? That's for the best. The Canadian Dental Association recommends brushing your teeth for two to three minutes, at least twice a day!