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Limited evidence shows for endodontic retreatments that although periapical endodontical surgery appears to be initially more successful than a nonsurgical approach on the long-term this relationship is reversed.

Analia Veitz-Keenan DDS .


Systematic Review Conclusion

Endodontic surgical retreatment offers a more favorable initial success, but the nonsurgical retreatment offers a more favorable long-term outcome

Critical Summary Assessment

This systematic review was limited by heterogeneity among the included studies and its conclusions were primarily drawn from indirect comparisons.

Evidence Quality Rating

Limited Evidence

Structured Abstract

Clinical Questions:

In periodontally sound teeth that require endodontic retreatement because of persistent periapical pathosis and/or clinical symptoms, does nonsurgical treatment produce better outcomes (clinically or radiographically) than surgical treatment?

Review Methods:

The authors searched three databases for articles published in English from January 1970 to July 2008 that reported data from clinical and/or radiographic outcomes related to nonsurgical/surgical endodontic retreatment. Inclusion criteria included studies that reported data for a minimum of 25 teeth with a minimum two-year mean follow-up period. They did not specify acceptable clinical or radiographic outcomes in their inclusion criteria. The search and study quality assessment was done by more than one reviewer.

Main Results:

The authors identified 721 articles, of which they selected 88 for full-text review. They selected 26 articles that addressed endodontic surgery which were compared to 8 that addressed nonsurgical retreatment. The meta-analysis included a total of 8,198 teeth. Sample sizes ranged from 27 to 1,016 subjects. Follow-up periods ranged from 2 to 6 years. The majority of the studies included a combination of tooth types. For follow-up periods from 2 to 4 years the weighted success was 77.8 percent, which declined to 71.8 percent at 4 to 6 years, and further declined to 62.9 percent at six or more years. The nonsurgical retreatment success rates demonstrated a statistically increase in success from 2 to 4 years at 70.9 percent, to 4 to 6 years at 83 percent. There were an insufficient number of articles to make comparisons for follow-up period longer than six years. Only one randomized clinical trial study directly compared surgical and non-surgical approaches and showed a success rate of 59.7 % for apical surgery and 54.17% success for non-surgical treatment.


This systematic review suggests that teeth retreated surgically have a higher rate of success than teeth non-surgically retreated after two years of follow-up. However, after six years of follow-up, nonsurgical treatment appears more successful than the surgical treatment.

Source of Funding:

Not specified.


Importance and Context:

Initial root canal therapy has been shown as a predictable procedure with a high degree of success, although failures can occur after treatment (14 percent to 16 percent). Should failure occur and preserving the tooth is possible, the practitioner should elect the best treatment approach. Surgery provides more direct access to the periapical lesion, but tooth location and anatomic considerations can limit this treatment option. In many cases, apical surgery temporarily can resolve the symptoms. However, should this approach miss a canal needing treatment, the primary etiology will not be removed

Strengths and Weaknesses of the Systematic Review:

The authors used accepted methods for defining search strategy and performing a quality assessment (type of study, number of patients, number and type of procedures, study settings, materials used, age of the patients, length of follow up and specific outcomes) of the selected studies. They standardized data to assess outcomes for nonsurgical and surgical endodontic. Comparisons were made among techniques and materials used. Weighted success rates, pooled success rates, and 95 percent confidence interval (CI) estimates of outcomes were generated in the meta-analysis from compiled data from the included studies. Although a meta-analysis was done the reporting of it did not follow standard procedures.

Strengths and Weaknesses of the Evidence:

Of the 30 studies the authors selected, only one RCT that directly compared the two modalities. Many of the published studies had insufficient information to address the quality assessment. Only four RCTs fulfilled the inclusion criteria. The mean total quality score, out of a possible 17 points, was 7.1 for nonsurgical and 5.5 for surgical studies. Regarding techniques and materials, the surgical treatment studies had more heterogeneity than the nonsurgical treatment studies. The nonsurgical treatment studies generally provided more information. Because of the high heterogeneity among studies regarding methods and outcome measurements, meta-analysis results should be cautiously interpreted.

Implications for Dental Practice:

Although the nonsurgical approach seems to be the better long-term option; the actual differences between treatment modalities may not be significant due to lack of a direct comparison. Other factors like cost, morbidity, presence of correctable technical deficiencies of previous treatment, obstructions to nonsurgical access, cosmetic implications, surgical access and other considerations need to be put in perspective before making a final decision.

Critical Summary Publication Date:


These summaries are not intended to, and do not, express, imply, or summarize standards of care, but rather provide a concise reference for dentists to aid in understanding and applying evidence from the referenced systematic review in making clinically sound decisions as guided by their clinical judgment and by patient needs. American Dental Association © 2018