甘いもの食べ過ぎちゃ駄目。 虫歯になるよ。
Don't eat too many sweets. You'll get cavities.
歯が痛いの？ ママに見せてごらん。あー! 虫歯ができてるよ。
Do you have a toothache? / Does your tooth hurt? Let me [mommy] see. Oh! You have a cavity.
何か食べるごとに歯を磨けなんて言わないから。でも少なくともご飯食べた後、お水でお口ゆすぎなさい。
I won't tell you to brush your teeth every time you eat something but at least, rinse your mouth with water after every meal.
赤ちゃんの歯が生え始める
あら、あの子の歯が生えてきてるわ！ 気付かなかった…
Oh, his teeth are coming in! I didn't notice.
歯が生え始めてきたみたいね。痛くないといいけど。
It seems like he's teething. I hope it doesn't hurt him.