There is a common misconception which surrounds the days of fasting in Ramadan. They say that brushing your teeth with a toothpaste and toothbrush invalidates the fast. So Muslims in different parts of the world go about their day without brushing their teeth while they are fast. But is that what Islam really commands? Does brushing the teeth invalidate the fast? Fortunately, NO.
On the contrary, Islam is a religion which pays attention to the cleanliness, good appearance and smell of its adherents. Muslims are recommended to appear decent and clean. They also are to keep their mouth clean by using a brush or siwak (tooth stick, also known as miswak). As the Prophet (peace be upon him) once said, “Cleanliness is a part of faith.”
Adhering to the fasts does not mean you compromise on basic cleanliness and oral hygiene. In fact, the Prophet (peace be upon him) would use a tooth stick (called siwak) while he was fasting to uphold the principle of hygiene.
Abu Dawud and At-Tirmidhi report an authentic hadith narrated by `Amir ibn Rabi`ah. He said: “I have seen the Messenger of Allah (peace and blessings be upon him) using a tooth-stick (siwak) while he was fasting more often than I could count.”
How about brushing the teeth?
In the modern world, it is not a very common practice to use the siwak. The tooth stick, popular at the time of the Prophet (peace be upon him) has been replaced by a toothbrush and toothpaste. The tool might have changed – but the concept remains the same.
It is absolutely acceptable and permissible in Islam to brush one’s teeth in the morning with toothpaste while fasting so long as one takes care not to swallow the paste.
It is only when the toothpaste enters your system (by swallowing), that your fast is affected. Since, the toothpaste is not used with the intention of consumption, using it to clean your teeth cannot be deemed as invalidating your fast.
However, if you fear that you could swallow the toothpaste, then you can use the Siwaak, which is easily available in the markets.
There is another interesting hadith which springs up.
The Prophet (peace be upon him) warned us against rigidity: “Woe to those who practice rigidity; woe to those who practice rigidity; woe to those who practice rigidity.”
And Allah knows best.