Post wisdom tooth extraction, I get a white patch of tissue near surgical site. Is that scar tissue?

Hello doctor,

Approximately one week ago, I had my wisdom teeth removed. On my lower left, I have a dry socket, which I am getting treated for via packing (at least I think that is what it is called). On the right side, healing is just fine, however, I noticed some white stuff lodged in the gum. I am not sure if it is food or scar tissue because when I tried to get it out with a toothpick, it did not come out very easily, so I left it alone. Is this food or scar tissue? It is mildly bothersome.

I brush my teeth but know to be careful around the surgical sites so they do not get irritated. It seems like a lot of plaque builds up back there because of this, and I am not quite sure what to do. Also, there is a very small spot of red gums on the front side of my second molar. I put a bit of mouthwash on it with a toothpick and left it alone.

I have two questions, what is the whitish stuff that feels like food trapped in my healing gum socket? And what is this small patch of irritated gum on my second molar? Any help is appreciated.

I am currently on Celexa (for depression), 600 mg of Ibuprofen (for wisdom tooth pain).