This can inflame tiny nerve fibers that SURROUND the root of the tooth, causing
pain. The
root canal procedure removes the nerves
from inside the tooth, but the fibers surrounding it remain (called the periodontal ligament) and can elicit pain, especially to pressure. In the absence of thermal sensitivity, you can rest pretty well knowing the nerves inside the tooth are gone. This narrows the focus for finding the source of your discomfort considerably.