I have been having pain in a root treated tooth which has now been extracted. i am now still getting sensitivity pain in the gap and other teeth?

Teeth next door: When you get a tooth removed, sensitivity or pain could be coming from the teeth adjacent to the extraction site. The technique to remove teeth sometimes puts pressure on the teeth next to the bad tooth. This can leave it sensitive. Also as the gums shrink where the tooth was removed....The adjacent teeth could be getting their roots slightly exposed to air also. See the doctor if need be.

Gum shrinks: You probably had the gum shrink around the teeth next to the space. Thereby the root surface is exposed making the teeth around the space sensitive. Try pro-enamel tooth paste. And have the tooth replaced.