Though toothpaste as we know it today is only about a century old, dental hygiene has long concerned human beings. The ancient Greeks and Romans cleaned their teeth with abrasive mixtures using crushed bones and oyster shells, a far cry from the hydrogen peroxide-and-baking soda formulas of the 19th century. In 1892, American dentist Washington Sheffield became the first to sell toothpaste in a tube—today the standard in toothpaste packaging. What had inspired him to package it like that? Discuss