Oral surgery can often involve complications. Hopefully now that you're being dealt with by another practice, they will sort out your complications. That doesn't sound like fun at all.
MS is an autoimmune disease, meaning that our bodies attack our own central nervous system. In this sense, our immune systems are over-active, not under-active. In fact, many of the next generation of medications (anything ending with -imab) are full on immunosuppressants. This has been found to reduce MS-based relapses, though the medications themselves can cause some issues.
So no, MS itself would not cause the issues you describe, though its possible *some* medications used to treat MS could cause healing times to take longer or allow opportunistic infections to occur.
This type of thing happening after teeth extractions is 'not' because of a faulty immune system, an over active immune system or related to MS......generally green is caused by an infection in the socket, which can happen if the tooth being removed was decade but it can also be caused by a post extraction infection. I did a quick google search and this was just the first...
"....the immune system starts to produce more white blood cells to counter the incoming threat. These white blood cells contain a green enzyme called neutrophils and they can cause your mucus to turn into different colors. Since the green mucus is appearing from the wisdom teeth extraction hole, there is a good likelihood that you are affected by some sort of teeth infection.
This infection may not have necessarily arisen as a result of the teeth extraction process. If you have any decayed tooth, this may have caused green mucus to form in the wisdom tooth socket. "
http://www.dentistshateme.com/2014/01/25/how-to-get-rid-of-green-mucus-from-wisdom-teeth-extraction-hole/
I'd contact your dentist because you probably need antibiotics etc
Cheers.......JJ