My dentist did not use a vacuum while he was washing my teeth before applying braces, and i swallowed like half a glass of liquid. the taste of that liquid was sour. is it safe for the body?

Contact DR. ARNOLD MALLERMAN on health tap for best advice.

Probably either an etchant used to prepare the tooth surface. It tastes sour because it's a very mild acid, about as acidic as pickles juice. So you will be just find. If you don't want to taste it again, totally and completely avoid hard/sticky/chewey foods that can dislodge your braces.