Recently I went through about 9 days of toothache pain on my lower left molar area. The pain would spike, usually when I laid down for sleep. I finally went to the dentist and he did an xray but it did not show an abcess/infection. He performed a sensitivity test by using ice. (Previously, about 4 months ago that molar tooth was sensitive to cold and specialist recommended a root canal. Did not go through with it because it only hurt when I had cold cold drinks in my mouth) I had no reaction to the ice from the dentist and so he then took out a device that would transmit an electric current through the tooth. I felt nothing. He recommended also a root canal. He gave me antibiotics and pain relief medicine. After leaving the dentist, I did not have anymore pain and I had not started taking the pain relief medication he prescribed. Does this mean that my tooth nerve is already dead since I cannot feel cold or pain anymore? Do I still need a root canal?