During ramadan before fajr I brush my teeth and then start my fast. But I have noticed that the taste of the tooth paste does not go for a long time and even 2 hours after when I touch my teeth with my tongue there is some taste of the toothpaste after rinsing with water several times. I want to if I swallow my saliva while having this taste would that break my fast?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The taste of the tooth paste that you find after washing your mouth does not harm because it is like what is mixed with the saliva from the remnants of food, and which is difficult to separate or to avoid.

Al-Fataawa al-Fiqhiyyah authored by al-Haytami reads:

"If there is some food between the teeth of the fasting person that is mixed with his saliva, and he could not separate it and spit it, then he does not break his fast by swallowing his saliva that is mixed with it, even if he swallows his saliva deliberately as it is difficult to avoid, because if we entrust him not to swallow his saliva, then this will be difficult, so he is excused (forgiven) for this."

The Mukhtasar of al-Muzani reads:

"If there is between his teeth [i.e. of a fasting person] what is mixed with his saliva, then he is not required to make up (this day)."

For more benefit, please refer to Fatwa 114031.

Allah knows best.