Hello, thank you for consulting with healthcaremagic. If your mother has noticed yellow colour fluid coming out it means there is an infection which is leading to formation of this pus discharge. The dentist must have taken an x - ray in which he must have identified that the front tooth are infected that is why he is telling to get them removed. So I think you should follow his instructions and still if you have a doubt you can go to another dentist and get the culture of this pus done which will give you the name of the bacteria. Hope it will help you.