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Web Exclusive | March 4, 2009

The Science behind endodontic failures

Research continues to demonstrate the overall effectiveness of endodontic treatment with a proper seal. However, studies also show that when a seal breaks down, contamination and treatment failure can result.

In a 1991 study examining the cause of failure of endodontically treated teeth extracted over a one year period, 59.4% were prosthetic failures, primarily due to marginal breakdown and fracture.¹ Teeth that had been crowned had significantly greater longevity than teeth without crowns. Over a three-and-a-half year period, 95% of endodontically treated teeth that were restored remained functional, according to a more recent study.²

Another investigation showed a significant amount of coronal leakage is evident when a root canal has been exposed to artificial saliva for as little as three days.³

Additionally, 50% of single-rooted teeth obturated using lateral condensation and then exposed to a microbial population were contaminated with bacteria along the entire length of the root canal after 19-42 days (dependent on the microorganism).⁴

With the findings of these studies are considered, it is easy to understand the importance of obtaining an effective seal after an endodontic procedure. Whether the crown being placed is a temporary or permanent restoration, the seal needs to prevent leakage for as long as that crown will be in place.


Click here for the Clinical 360° Endodontics article: An adequate seal is key, even if only temporary

References

1. Vire DE.  Failure of endodontically treated teeth:  classification and evaluation. J Endod 1991;17(7):338-42.

2. Lazarski MP, Walker WA, Flores CM, Schindler WG, Hargreaves KM.  Epidemiological evaluation of the outcomes of nonsurgical root canal treatment in a large cohort of insured dental patients.  J Endod 2001;27

3. Swanson K, Madison S.  An evaluation of coronal microleakage in endodontically treated teeth.  Part I.  Time periods.  J Endod 1987;13(2):56-9.

4. Torabinejad M, Ung B, Kettering JD.  In vitro bacterial penetration of coronally unsealed endodontically treated teeth.  J Endod 1990;16(12):566-9.