Why did the tortilla chip go to the dentist?

This joke cracks us up with some clever wordplay, which is a common humor mechanism in many puns. The whole gag hinges on the double meaning of the word "filling." When you think of a dentist, a "filling" is a common procedure to repair a tooth. But when you think of a delicious tortilla chip, a "filling" could also refer to the tasty dips or toppings that often accompany them, like salsa, guacamole, or nacho cheese.

Tortilla chips themselves have a rich history, originating in Mexico and becoming a staple snack, especially popular with various "fillings" or dips. The idea of a chip needing a dental filling is, of course, absurd, which adds to the silliness. It's the unexpected twist of applying a human dental need to an inanimate snack food, then cleverly linking it to something a chip *would* realistically be associated with in the culinary world, that makes this joke so enjoyable and a perfect example of a well-crafted pun.