DENTIST, n. A prestidigitator who, putting metal into your mouth, pulls coins out of your pocket.

Ambrose Bierce (1842–1914?) American writer and journalist

“Dentist,” The Cynic’s Word Book (1906)
    (Source)

Included in The Devil's Dictionary (1911). Originally published in the "Devil's Dictionary" column in the San Francisco Wasp (1882-02-17).