虫歯

• Reading: むしば
• Romaji: mushiba
• Kanji breakdown: 虫 (mushi) — insect, bug; 歯 (ha/ba) — tooth
• Pronunciation: /mɯ.ɕi.ba/

Meaning

Cavity; tooth decay; decayed tooth. A dental condition caused by bacteria.

A noun for dental caries or cavities. The name literally means 'bug tooth,' reflecting an old folk belief that tiny bugs caused tooth decay. Common expressions include 虫歯になる (to get a cavity), 虫歯を治す (to treat a cavity), and 虫歯予防 (cavity prevention). Children are frequently reminded about 虫歯 to encourage brushing.

Examples

1. 甘いものを食べすぎて虫歯になった。 I got a cavity from eating too many sweets.
2. 歯医者で虫歯の治療を受けた。 I got my cavity treated at the dentist.
3. 毎日歯を磨かないと虫歯になるよ。 If you don't brush your teeth every day, you'll get cavities.

Usage Guide

Context: health, dentistry, children

Tone: concerned

Origin & History

Compound of 虫 (mushi, bug/insect) and 歯 (ha/ba, tooth). Reflects the ancient belief, shared across many cultures, that tooth decay was caused by tiny worms or insects eating into the tooth.

Cultural Context

Era: Ancient

Generation: All ages

Social background: Universal