The Endo Archive

News from Endodontic Specialists of Madison, S.C.

Implants vs. Root Canals and Success vs. Survival - January 31, 2013

Although retaining the natural dentition is preferred when possible and root canal success rates are high, there are limitations to root canal treatment. Microanatomy within the root canal system can prevent complete cleaning and disinfection of the root canal system. (1) Certain bacteria may be resistant to current disinfection techniques or could penetrate dentinal tubules gaining access to a location within the tooth that can’t be reached with instruments or irrigants. (2,3) Fractures can lead to persistent infection and/or recontamination of the root canal system. As a result, some teeth cannot be saved even with the best possible root canal outcome. If a tooth can’t be saved with conventional root canal treatment or apical surgery and extraction is necessary, restoration of the space with an osseointegrated implant may be the treatment of choice.

With this in mind, current literature doesn't support the removal of a necrotic but periodontally sound, restorable tooth to place an implant. Doyle et al. found restored endodontically treated teeth and single-tooth implant restorations have similar failure rates, although the implant group took a longer time to function and had a higher incidence of postoperative complications requiring subsequent treatment interventions. (4)  Moreover, other clinical factors may impact the success of both implants and root canal treatment. (5)

Preoperative image of a previously treated root canal in tooth #30 that has post treatment disease. Although bone loss in the furcation area is suggestive of a root fracture, the incomplete nature of the previous root canal could be the etiology for the apical and furcation breakdown. Treatment options for this tooth included retreatment or extraction. Because of the limited restorative histories in the adjacent teeth and the available bone, this area would likely have been restored with an implant if extraction were necessary.

The patient wanted to retain the tooth if possible and chose retreatment - with the understanding that the technical outcome of the original root canal was not ideal and if a fracture was identified the tooth would be extracted.

Six month follow-up showing excellent bone fill and a permanent restoration in an asymptomatic tooth.

In another study, three databases were searched for studies on the survival of single-tooth implants and restored endodontically treated teeth.  Inclusion criteria were met by 57 studies on single-tooth implants (~12,000 implants) and 13 studies with restored, endodontically treated teeth (~23,000 teeth).  The outcomes for the two treatments were equivalent. There was no difference between the implant and endodontically treated teeth in any of the observation periods. (6)  In terms of costs, a 2005 insurance data review concluded that restored single-tooth implants cost 75-90% more than similarly restored endodontically treated teeth. (7)  Thus, the restored endodontically treated tooth offers considerable economic advantages to the patient.

Salehrabi looked at outcomes of initial endodontic treatment done in 1,462,936 teeth of 1,126,288 patients from 50 states across the USA over a period of 8 years. Treatment was completed by general practitioners and endodontists participating in Delta Dental. Overall, 97% of teeth were retained in the oral cavity 8 years after initial nonsurgical endodontic treatment. Of the treatment failures, 85% did not have full coronal coverage after root canal treatment. (8)

In spite of these results, it seems that implant success is often regarded as superior to root canal treatment in most clinical situations.  This may be due to differences in the definitions of success and survival.  Success in the endodontic literature means asymptomatic with no detectable radiolucency, while a more lenient definition of “success” for an implant means survival in the bone, in spite of any bone loss (1 mm of bone can be lost during the first year of placement, with an additional 0.1mm annually).  Additionally, most of the implant treatments have been provided by specialists, while many of the root canal studies have included not only specialists, but general practitioners and dental students. (9, 10)

Given the best available evidence, it seems fair to draw the same conclusions as Iqbal and colleagues. “Since outcomes are similar with either root canal treatment or implant placement, treatment decisions should be based on other factors such as restorability, costs, esthetics, potential adverse outcomes and ethical factors.” (6)

Radiograph showing weil integrated implants in the 9 and 10 positions. These implants would certainly be classified as a success when evaluating healing and prognosis.

The clinical photo shows a different story. Although the implants have integrated, the esthetics are far from ideal.

No clinician would consider this endodontic treatment outcome a success. However, if success were defined as survival, this would be classified as a positive outcome even though the toorh is not restorable.

REFERENCES

1) Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol 1984;58(5):589-99.
2) Byström A, Claeson R, Sundqvist G. The antibacterial effect of camphorated paramonochlorophenol, camphorated phenol and calcium hydroxide in the treatment of infected root canals phenol. Endod Dent Traumatol 1985;1:170-175.
3) Figdor D, Davies JK, Sundqvist G. Starvation survival, growth and recovery of Enterococcus faecalis in human surum. Oral Microbiol Immunol 2003; 18:234-239.
4) Doyle S, Hoidges J, Pesun I, Law A, Bowles W. Retrospective cross sectional comparison of initial non-surgical endodontic treatment and single-tooth implants. J Endod 2006;31.
5) Doyle S, JS H, Pesun I, Baisden M, Bowles W. Factors affecting outcomes for single-tooth implants and endodontic restorations. J Endod 2007;33:399-402
6) Iqbal M, Kim S. For Teeth Requiring Endodontic Treatment, What Are the Difference in Outcome of Restored Endodontically Treated Teeth Compared to Implant-Supported Restorations? International J Oral Maxillofac Implants 22(Suppl):96-119, 2007.
7) Christensen GJ. Implant therapy versus endodontic therapy. J Am Dent Assoc 2006;137(10):1440-3.
8) Salehrabi R, Rotstein I. Endodontic treatment outcomes in a large patient population in the USA: an epidemiological study. J Endod 2004;12:846-50.
9) Lazarski MP, Walker WA, 3rd, 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(12):791-6.
10) Alley BS, Kitchens GG, Alley LW, Eleazer PD. A comparison of survival of teeth following endodontic treatment performed by general dentists or by specialists. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98(1):115-8.