Zaid Alsalami, Shaykh Dr Zaid Alsalami is an Iraqi born scholar, raised in Australia. He obtained a BA from Al-Mustafa University, Qom, and an MA from the Islamic College in London. He also obtained a PhD from... Answered 1 year ago

 Bismihi ta'ala

Seeing that you rinsed your mouth, and you spat out the water, that would be sufficient, and your fasting is valid, even though your tastebuds still feel the taste of toothpaste. Of course, this is as long as there is no remaining traces of the toothpaste itself, and you swallow the natural saliva in your mouth.

And Allah knows best.