Tooth extraction. sinus exposed. now a white puss like circle in mouth next to where tooth was. what do i do? dentist looked for ten sec. didn't care.

More info needed: How far post op are you with the extraction? Are you absolutely sure you have a sinus communication? If so, your dentist needs to manage your post surgical situation or refer you to an oral surgeon. All the best.

What to do: It's difficult if not impossible for us to evaluate these types of situations over the internet, sight unseen. Based upon your description I too would have some concern, and you certainly deserve an explanation as well as having all your questions answered. If you do not have confidence in your dentist, get a second opinion from an Oral Surgeon.

Second Opinion: In many cases, seeking a second opinion is not only warranted, but necessary. Unless your disease is life threatening and requires emergency care, it is never a bad idea to seek a second opinion. Getting a second opinion helps you feel more confident about your diagnosis and treatment plan.See OMS for second opinion.