INTRODUCTION Toothpaste has a history that stretches back nearly 4,000 years. Until the mid-nineteenth century, abrasives used to clean teeth did not resemble modern toothpastes. People were primarily concerned with cleaning stains from their teeth and used harsh, sometimes toxic ingredients to meet that goal. Ancient Egyptians used a mixture of green lead, verdigris (the green crust that forms on certain metals like copper or brass when exposed to salt water or air), and incense. Ground fish bones were used by the early Chinese. In the Middle Ages, fine sand and pumice were the primary ingredients in teeth-cleaning formulas used by Arabs. Arabs realized that using such harsh abrasives harmed the enamel of the teeth. Concurrently, however, Europeans used strong acids to lift stains. In western cultures, similarly corrosive mixtures were widely used until the twentieth century. Table salt was also used to clean teeth. In 1850, Dr. Washington Wentworth Sheffield, a dental surgeon and chemist, invented the first toothpaste. He was 23 years old and lived in New London, Connecticut. Dr. Sheffield had been using his invention, which he called Creme Dentifrice, in his private practice. The positive response of his patients encouraged him to market the paste. He constructed a laboratory to improve his invention and a small factory to manufacture it. Modern toothpaste was invented to aid in the removal foreign particles and food substances, as well as clean the teeth. When originally marketed to consumers, toothpaste was packaged in jars. Chalk was commonly used as the abrasive in the early part of the twentieth century.