Tongue fur is one of the primary causes of bad breath and it also looks dirty so I always watch out for it.
Tongue fur is one of the main causes of bad breath and also just looks filthy, so I always make sure to remove it.
舌苔 = tongue fur
口臭 = bad breath; halitosis
主要因 = main cause; primary cause
見た目 = looks
不潔 = dirty; filthy
気を配る = pay attention; keep an eye on (目を配る; watch out for
「歯磨きと同じくらい大事でしょ」＝ I think it's just as important as brushing your teeth.