noun
Standard word for a toothbrush; no special nuance or register.
新しい歯ブラシを買った。
I bought a new toothbrush.
歯ブラシで歯を磨く。
I brush my teeth with a toothbrush.
Standard kanji-katakana spelling; the most common written form.
Rarely used kanji form; learners will almost never encounter this spelling.
歯磨き refers to the act of brushing teeth or toothpaste, while 歯ブラシ specifically means the toothbrush tool.
Compound of 歯 (ha, 'tooth') and ブラシ (burashi, from English 'brush').