Sinus Buildup Above Teeth Causing Tooth Ache. Anyone know the cause?

Hey guys. So this past weekend, I randomly had really intense tooth pain thinking I had to get my wisdom teeth pulled out. This has happened before about a year ago actually. I went to the dentist last time and got x rays only to have the doc tell me that I simply had sinus buildup in my gums above my teeth.

I was thinking I actually had to get my wisdom teeth this time, but get this, it was about 100 degrees this past weekend and really humid. As soon as the sun set and it was a little cooler out, my pain in my teeth went away completely.

I'm pretty sure it was the same sinus buildup above the gums, but not sure of the cause. I have heard sinus is fungal related, could this be it?