RCT done. Paining. Does the pain spread?

Recently RCT was done for me in my upper left chewing tooth . Only 1st sitting done. Endodontist did temporary filling asked me to come after 12 days. I did it at Balaji Dental College Chennai. I have been given Antibiotic and paracetamol pain killer. Now I have pain in the RCT (chewing upper )tooth and also over the front tooth,lower tooth& gums. The pain spreads to the lower tooth and gums. What could be the problem? Why does the pain spread? In-between the RCT tooth and other tooth there is a gap. Food particles get stuck there, hence I went to do RCT. The Dentist student did temporary filling but did not fill the gap between RCT tooth and other tooth. So my tongue keeps pressing the gap between the teeth. When ever my tongue presses against the gap in between the teeth, I develop pain which radiates to my ear and left side of head. I told all this to Endodontist girl before RCT. She doesn't seem to have filled the gap between the two teeth.