Reference:: Fataawa Ramadhaan v2 p496 no.445
al-Muntaqaa min Fatawaa ash-Shaykh Saalih ibn Fowzaan v3 no.158
Question: Is it permissible for one who is fasting to use toothpaste during the day?
Response: It is permissible for one who is fasting to use toothpaste, being careful that nothing from the solution goes down his throat. It is preferable he clean his mouth with a miswaak and other than it from that which doesn’t reach the throat, just as one should not exaggerate whilst gargling the water in the mouth during ablution.
