Dr. Zakir Naik was asked whether it is allowed to use toothpaste to brush your teeth while you are fasting in the month of Ramazan?
He responded that most scholars allow the use of toothpaste because it’s same as miswak which Prophet (PBUH) allowed to use during fasting. But he mentioned that if the toothpaste is swallowed it will break the fast (roza).
Mufti Muhammad Akmal was asked the same question to which he also responded in the same manner. But he said as there is chances that toothpaste will be swallowed it is better to brush your teeth before sehri and then during fasting use miswak.
He further explained that miswak was used by the Prophet Muhammad (Pbuh) who also recommended using it. He concluded that toothpaste should be used before sehri and after iftar while miswak should be preferred during fasting.