Hi one of my friend went to a ent, her throat was paining as there was a fish bone stuck, she went to doctor and since it was inside the mouth so doctor used anesthesia spray to numb the area and get a better view however thankfully there was a small injury because of the fish bone. I have not heard of mouth anesthesia, is it harmful in long term? Will there be any side effect? Or any sign that we need to watch because of the anesthesia as she swallowed the saliva the moment it was spray please advise thank you.