I went to the dentist last week and found out I need work on my bottom teeth, I now have a shocking cold with blocked sinus and my top back 2 teeth have started to ache something terrible, the dentist couldn't find anything wrong with my top teeth last week is it possible that the ache is due to the cold and cough that I have. Any help would be greatly appreciated.

Could be yes.. sinus infection can cause an apparent pain in the top molars... if it hurts to tap on more than one tooth (and there is no apparent dental cause) it's a safe bet it's a sinus issue... give it some time and see how it turns out, and see your physician to check out that cold

Definitely could be due to the sinus. Try taking an antihistamine.