Before a tooth can be treated a diagnosis must be made to confirm the source of pain or infection. The status of the tooth is diagnosed using simple tests that will reveal the offending tooth and potentially simulate the symptoms you have been experiencing. The other part of diagnosis is determining whether or not the tooth should be saved. Just because a tooth needs a root canal does not mean that we should do it. Teeth that have deep cracks (which are sometimes found after treatment is started) or minimal tooth structure often have a poor prognosis. Once the tooth causing pain has been confirmed and deemed restorable the treatment can be started.