Can I brush my teeth with toothpaste while fasting?
We have several answers to that. You cannot swallow toothpaste while fasting because swallowing toothpaste or saliva affected by toothpaste would break your fast. However, the use of toothpaste does not in itself invalidate the fast unless you swallow the toothpaste itself or saliva affected by it.
Anything that could reasonably break your fast, deliberately choosing to do so in general is disliked. Because breaking your fast is prohibited.
That which comes close to something takes something of its rulings.
So deliberately choosing to put anything in your mouth that you could end up swallowing, and thereby invalidating your fast, would be disliked if it’s without reason.
So, toothpaste, in general, will take that ruling as well. After the fast begins, one would avoid it.
But there are circumstances, particularly if someone’s going to work, etc and if your breath is affected, then if you are to use toothpaste and when there’s a need–and it’s disliked–it’s not prohibition. If there’s a need, then just use very little toothpaste and rinse your mouth.
And if you rinse out once you’re considered to have rinsed out the toothpaste any residual taste after that is excused.
So, if there’s no need, you’re just, it’s Saturday, you’re at home, and if you take care of your oral hygiene and you brush before the day starts, it, you should make it to the end of the day.
Don’t have garlic at sahoor time.
The Ruling of Miswak
But also, it’s useful to learn how to use a tooth stick, sewak, because the tooth stick, right, this sewak or the miswak does not require any external agent for you to brush your teeth.
Alright, so if you keep a toothpick, learn how to use it.
And it’s very useful. You can use it all day. Now you keep it moist so that the ends don’t come off.
But again, you use it once and then you rinse your mouth out once and that’s enough.
And you can use the toothstick in the Hanifi school, all day: in the Shafi’i school, only up till midday.