Do dental bleeding and swallowing the blood coming out of dental wound with saliva invalidate the fast? Does swallowing blood from a dental wound interrupt the fast? Can swallowing blood mixed with saliva from a dental wound invalidate the fast?

Dental bleeding does not invalidate the fast. However, if the blood is equivalent to or more than the spit that is mixed with and swallowed, fasting is invalidated and qada is required. The blood in less amount is not taken into consideration. (Haddad, al-Jawhara, I, 173)

Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS

Does Having Dental Treatment Invalidate Fasting?