The world’s oldest-known formula for toothpaste dates as far back as 4 A.D., when Egyptians combined crushed rock salt, mint, dried iris flower and pepper into a cleansing powder. Toothpaste formulas have come a long way since then, as has our understanding of the importance of oral health.

The first commercially produced toothpaste was launched by Colgate in 1873 and sold in a jar. But the real breakthrough came after researchers in Colorado discovered an epidemic of children with brown, mottled teeth that were surprisingly strong and resistant to cavities. It turned out their well water contained far too much fluoride, a naturally occurring mineral.

Researchers eventually found optimal levels for fluoride in water. And in 1955, Proctor & Gamble introduced Crest, a toothpaste that contained fluoride to protect teeth from decay. Today, fluoride toothpaste makes up more than 95 percent of all toothpaste sales in the United States.