There are other items used for mouth hygiene, such as mouth-wash or dental floss, however I think that you are simply referring to toothpaste which we use with a toothbrush.
I need to buy some toothpaste.
I forgot my toothpaste at home.
Etc.
mouth-washやdental floss(糸ようし)など色んなデンタルケア用品がありますよね。けど歯ブラシと一緒に使うのは基本toothpasteと言いますね。
例
I need to buy some toothpaste.
歯磨き粉をかわなくちゃいけない。
I forgot my toothpaste at home.
歯磨き粉を家にわすれてしまった。
こんにちは。
「歯磨き粉」は英語で toothpaste(トゥースペースト)と言います。
「歯ブラシ」は toothbrush(トゥースブラシ)です。
【例】
I need to buy toothpaste.
「歯磨き粉を買わなきゃ」
I forgot my toothbrush.
「歯ブラシを忘れてしまいました」
ちなみに「歯を磨く」は brush (one's) teeth という表現を使います。
【例】
Did you brush your teeth?
「歯磨いた?」
ぜひ参考にしてください。
Toothpaste
This is a paste or a gel substance used on a brush for cleaning one's teeth
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Example
I need to buy a new tube of toothpaste.
Toothpaste
これは歯を磨くためにブラシにつけるペーストまたはジェル状の物質です
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例
I need to buy a new tube of toothpaste.(新しい歯磨き粉(チューブ)を買わなくちゃ)
Toothpaste is the stuff you put on your toothbrush when you brush your teeth.
It sometimes has a coloured stripe in it.
Some popular brands of toothpaste are Colgate, Oral B, Aquafresh, and Sensodyne. Toothpaste often has a minty taste.
The stuff you out on your toothbrush when you want to clean your teeth would be called, "toothpaste," sometimes this comes as a white, blue or red paste. Mouth wash is the liquid that you put in your mouth to burn the bacteria that is resting inside, typically this stings a little but it makes your mouth feeling very clean afterwards.