This was a case I treated at my office that (I hope) illustrates a very common situation (a tooth needing a root canal and buildup) and an explanation of why all those things are needed to save a tooth. This tooth had a large silver fillingwith a crack running down the middle and decay around the edges. The tooth was sensitive to cold and to pressure. Even before looking at an x-ray, I’m already in the mindset of this tooth needing a root canal because of the patient’s symptoms. An x-ray of the tooth shows the filling, the depth of the decay, and how close the decay is to the nerve of the tooth. Symptoms including lingering cold or hot sensitivity , pain to biting pressure, or unprovoked pain could indicate that the tooth needs to have the nerve removed (it is inflamed beyond repair or has become infected). The final step to all of this is to crown the tooth. An impression is taken, and then sent to a dental lab that fabricates this pretty (and strong) cover that gives the tooth the best possible chance of surviving long term. Crowned teeth can still have problems – they can break and they can get decay around the edges if not cleaned properly. But in many cases, including this one (a root canal treated back tooth), crowns are key to the tooth’s longevity.