永久歯 えいきゅうし Meanings Noun permanent tooth Kanji 永 eternal. Read as エイ. 久 long time. Read as キュウ. 歯 tooth. Read as シ. Example sentences 息子の乳歯が永久歯に変わりました。All my son's adult teeth are in. 乳歯が抜けないうちに後ろから永久歯がはえてきました。His permanent tooth is coming in behind his baby tooth. 娘の永久歯がはえてきました。My daughter is cutting her permanent teeth. Jinuma: Japanese Dictionary · Word lists