In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
It is Makrooh (severely disliked) to brush one’s teeth using toothpaste whilst in Ihraam. Hence, one must try his best to avoid its use. If one does use it, then he should make Istighfaar. No Sadaqah or Dum will be necessitated.[1]