I had teeth #14, crowned, root canalled, 3 roots are cleaned, sealed through bottom of crown, still sore.can 4th canal spread back to 3, 2, 1 if ..is?

Check bite: Your upper left first molar may have second mesiobuccal canal or just because you still have traumatic occlusion (hitting too hard), please your dentist to check that tooth in all jaw mocements.

Several possibilitie: A molar usually has 3 or 4 canals. 3 are easily found. The 4th is more difficult to locate and is missed many times. This can cause the root canal treatment to fail. However, there are several other reasons for post-op pain. 1) over instrumentation during cleansing of canals, 2) under instrumentation of canal leaving tissue 3) debris left in canal due to insufficient irrigation, 4)fracture of root.

No, but: This needs to be checked by your own dentist. It could be an incomplete or failed root canal therapy, a fracture of the crown or root, or simple the tooth is sore from contacting your other teeth prematurely, requiring a simple bite adjustment to resolve. If all normal clinical and radiographic tests fail to diagnose the problem, you might consider a cbct (3d image) to figure out the cause.