Complications with dental crowns: Required, unplanned root canal treatment.

If you think about the procedure from your tooth's point of view, the crowning process is a big event. A drill is used to grind a way essentially all of a tooth's enamel layer and a fairly substantial amount of dentin too. This drilling process involves friction and the accompanying heat that it produces. Drilling also creates jarring vibrations that are transmitted throughout the tooth. And because the dentin layer (the hard tooth structure that surrounds the tooth's pulp) is porous the mechanical action of the drill can pump bacteria into this layer towards the nerve tissue, thus causing pulp irritation.

Each of these separate events has the potential to traumatize a tooth to some degree. And the thinner the layer of dentin between the surface of the crown preparation and the tooth's nerve, the more significant the effects of these events can be. This factor can be especially problematic with those teeth that have very large pulps (such as the teeth of young people) or teeth where fracture has resulted in the loss of a large portion of tooth structure.

So, will the trauma produced by the crowning process cause your tooth to need root canal treatment?

Probably not. As you now know, if your dentist makes a dental crown for you and then during the process, some weeks later, or even some years later you find that you require root canal treatment its most likely just bad luck. The tooth has finally reached a point where its nerve tissue can no longer recuperate properly and be healthy. Yes, the trauma of making the dental crown could have, on its own, been the traumatic event that has caused the degeneration of the tooth's nerve tissue but more likely the crowning experience was simply the last event that finally pushed the health of the tooth's nerve over the edge. The crowning procedure precipitated the timing of an outcome that would have occurred anyway.

Should your dentist have anticipated your tooth's need for root canal treatment?

You can't really expect your dentist to be that all-knowing. As we stated earlier, dental crowns aren't placed on pristine teeth. They are used to rebuild teeth that have already received serious insult. There are tests that a dentist can perform so to evaluate the health of a tooth and most likely your dentist performed them before beginning the crowning procedure. But the results of these tests are often vague and difficult to interpret. Collectively they may all point to the same conclusion about the need for root canal treatment. And when they don't a dentist will probably hope for the best and not perform endodontic treatment on your tooth for fear that it is unneeded.