I went to the dentist because I was experiencing some sensitivity to heat/cold in my upper right teeth. He determined I needed a crown replaced. I got a temporary crown put on and afterwards the heat/cold sensitivity got MUCH worse. My dentist said it was irreversible pulpitis and said I needed a root canal. I got a second opinion and that dentist said the temporary crown was a very poor fit, no contact was being made between the crown and neihboring tooth, and my cross-bite was making it difficult to get the crown to meet right, food was probably getting under it, and the pain I was experiencing could likely be caused by the bad fit of the temporary crown. Neither dentist saw an abcess or obvious deterioration of the root on my XRay. I got the permanent crown put on yesterday using temporary cement to see if a better fitting crown would make the pain/sensitivity go away. After one day, the pain is still the same. How/when will I know if the pain is indeed being caused by the need for a root canal?