Tooth Brushing

Imam Abu Abdillah (as) was asked about the toothbrushing.
So He (as) said: Yes, he can brush teeth at whichever time of the day he so desires to.

In another narration, from Imam Abu Abdillah (as), having disliked for the Fasting-one that he brushes with the wet tooth-stick, and said: There is no harm if he dampens his tooth-stick with the water, then he shakes it until there does not remain anything in it.

[al Kafi, Volume no. 4]