I had some dental work done and now i have some kind of infection in throat that makes me spit up brown mucus ?

Dental work: Unfortunately, dental cleaning and any type of dental procedure can introduce bacteria into your bloodstream. This can be a major issue if you have mitral valve prolapse. In your case sounds like you have contracted a systemic infection caused by your dental work and you need to either contact your dentist, or general physician to determine if antibiotic intervention is warrented.

Coincidence: The throat infection is probably not related to the dental work but instead you are probably developing a cold.

Throat Infection: The dental work you had done and the throat infection most likely are not associated. If you have a throat infection see your physician or a ear nose and throat specialist. Allowing it to continue may lead to something worse.

Not related: You can check back in with your Dentist to make sure your post-restoration response is normal, but your throat symptoms are not related to your Dental work. Please see your General Physician ENT for throat evaluation.