This is the 12059th most frequent Russian word.
зубы
Teeth.
Here, 'зубы' refers to the physical teeth causing pain.
У меня болят зубы.
My teeth hurt.
'зубы' here are mentioned as objects for an action (cleaning) in the sentence.
Зубы надо чистить два раза в день.
Teeth must be brushed twice a day.
The term 'зубы' here describes the sharp teeth of a predator.