Reference: Fataawa Ramadhaan – Volume 2, Page 525, Fatwa No.492
Fataawa Shaykh Ibn ‘Uthaymeen – Volume 1, Pages 511-512
Question: Does an anaesthetic injection into the body break the fast? [And likewise] the blood flow after having a tooth extracted?
Response: Neither of these two breaks the fast, however, one must not swallow the blood which flows from [having] the tooth [removed].