Undergoing full root canal treatment and endodontics is a difficult, time-consuming and painful process, and as such it is only carried out when there is no other option to save a tooth from extensive decay or infection. However, if you are looking at the prospect of undergoing a root canal treatment, you may have an alternative -- if enough of the living pulp within your damaged tooth remains alive and healthy, you may be eligible for pulp capping.

What is pulp capping?

As tooth decay (more properly known as dental caries) eats away at a tooth, more and more of the protective enamel and dentin of a tooth is destroyed, eventually revealing the living pulp and nerve tissue within the tooth. More pulp can be exposed even as the decay is removed, as your dentist or endodontist will almost certainly be forced to remove a portion of the remaining healthy tooth in order to fully remove all traces of decay. These tissues are delicate and are not designed to come into contact with open air, so they are highly vulnerable to inflammation caused by infection, known as pulpitis. If left untreated, infected pulp tissue can eventually die, causing dangerous tissue necrosis (gangrene) which can provoke serious infections and even blood poisoning. As such, the priority of any dental treatment on a severely damaged tooth is to protect the pulp from exposure as much as possible.

During traditional root canal therapy, the possibility of exposed tooth pulp becoming infected is dealt with thoroughly, by removing all traces of pulp within the tooth and replacing it with inert artificial cement. The aim of pulp capping is to retain the healthy pulp and essentially keep the tooth 'alive' by promoting natural tooth restoration and keeping the exposed pulp sealed away from external pathogens. This is achieved in one of two ways:

  • Direct capping -- Direct capping is used when the pulp inside a damage tooth is fully exposed to the air. Once all decaying enamel and dentin is removed from the tooth, the exposed pulp is covered with a special medicated dressing. This dressing contains chemical compounds which provoke the cell-rich pulp to form a layer of replacement dentin to protect itself, essentially forcing the tooth to perform a (limited) reconstruction of itself. The dressing is then covered and sealed with a conventional filling.
  • Indirect capping -- This method is used when pulp is not yet exposed but removing all of the decayed parts of a tooth would necessitate exposing it. Therefore instead of the medicated dressing being placed directly on the pulp, it is placed over the portion of the tooth where the remaining dentin is thinnest. This dressing promotes dentin reconstruction in the same way as a direct capping and is covered with a temporary filling. This filling is then removed after a period of time and is replaced with a permanent filling if the capping process has been successful.

What are the benefits and drawbacks of choosing pulp capping over root canal therapy?

The main advantage of choosing a pulp capping is that the procedure is significantly less invasive than full-blown root canal therapy. As such, pain levels and bleeding are reduced both during and after the procedure, and the risk of complications arising is smaller. Pulp capping is also a much less complex procedure than root canal therapy, necessitating less time in the dentist's chair and under the endodontist's drill, and since a much smaller amount of artificial dental restoration materials are required the results of a successful pulp capping can be almost indistinguishable from a healthy tooth.

However, successful is an important word, and pulp capping is not a foolproof process. If the pulp of a tooth is already too badly infected, or dental caries are too large and advanced, the capping may fail and becoming infected, potentially necessitating full root canal therapy or even tooth extraction. In addition, because pulp capping relies on natural restorative processes, it will not return your tooth to full strength right away, and you may experience some pain and discomfort as dentin regrows over highly sensitive tooth pulp.