A new systematic review in the Journal of Endodontics found no statistically significant difference in failure risk between molar root resections done for endodontic reasons and those done for periodontal reasons. The authors rate the overall certainty of that evidence as very low, so the finding is a reason for careful case selection rather than a green light for either indication.
Root resection rarely makes headlines, yet it sits at the centre of a decision many practices face: keep a compromised molar, or plan its replacement. As of November 2026, there is a new pooled look at this question. In a systematic review and meta-analysis first published in the Journal of Endodontics in early November 2026, M. A. Sabeti and A. Wang of the University of California, San Francisco School of Dentistry asked a narrow, practical question. Does the reason you resect a root change how likely the tooth is to fail?
What is root resection, and when is it considered?
The authors frame root resection as a tooth-preserving option for selected molars. In their words, it is considered when endodontic retreatment or apical surgery is not feasible, or when periodontal furcation involvement compromises the tooth's maintainability. Those two pathways describe very different patients. In one, the main problem is endodontic and retreatment or apical surgery is not feasible. In the other, the tooth has lost periodontal support around the furcation.
That split is exactly what the review set out to compare. If one indication fails far more often than the other, clinicians would weigh resection differently depending on how the tooth arrived in the chair.
How the review was done
The authors searched PubMed/MEDLINE, Embase, Web of Science and Google Scholar through May 7, 2026. They included clinical studies of permanent molars treated with root resection that reported at least 10 cases and at least one year of follow-up. The protocol was registered with PROSPERO (CRD420251060463).
- Twelve studies met the inclusion criteria: five comparative studies that reported both indications, and seven that reported periodontal cases only.
- The five comparative studies covered 307 endodontically indicated and 520 periodontally indicated resections.
- Risk of bias was assessed with the Newcastle-Ottawa Scale, and certainty of evidence with GRADE.
- Results were pooled as crude within-study failure risk ratios (periodontal versus endodontic) using a DerSimonian-Laird random-effects model.
What did the review find?
The pooled failure risk ratio was 0.82 (95% confidence interval 0.56 to 1.21; P = .320), with an I² of 24.3% and a wide 95% prediction interval of 0.33 to 2.07. A ratio below 1.0 would mean periodontally indicated resections failed less often, but because the confidence interval crosses 1.0, the difference is not statistically significant.
The authors ran a sensitivity analysis that removed a claims-based study lacking individual follow-up. Restricting the analysis to four clinical cohorts with documented individual follow-up gave a similar, still non-significant result: a risk ratio of 0.74 (95% CI 0.50 to 1.08; I² = 10.3%).
Two further details matter for chairside conversations:
- In the periodontal-indication studies, periodontal disease progression was the most frequently reported cause of eventual extraction.
- Extraction causes for endodontically indicated resections were available from only one comparative study (29 teeth) and were reported narratively.
Why the authors call the estimate "fragile"
This is the part of the paper that deserves the most attention. The authors describe their meta-analytic estimate as methodologically fragile. It combines crude failure risks observed over substantially different follow-up periods, so it should not be read as a time-standardized survival comparison. Indication-specific time-to-event data and hazard ratios were inconsistently available, which is why the pooled risk ratio was treated as an exploratory summary.
The low I² values could look reassuring at first glance. The authors explicitly decline to read them that way: with only five studies and highly nonuniform follow-up, they did not interpret the I² estimate as evidence of low heterogeneity. Overall GRADE certainty was rated very low.
In plain terms, the review does not show that the two indications perform the same. It shows that the current literature cannot detect a difference with confidence.
What this means for treatment planning in Canadian practices
For general dentists in Toronto, Mississauga, Markham and across Ontario, root resection usually comes up in one of two ways: as an option you offer yourself, or as one you discuss before referring to an endodontist or periodontist. The review gives you an honest summary to bring into either conversation.
Pro Tip: When you present root resection as an option, tell the patient plainly that the published evidence on long-term outcomes is limited, and record that discussion in the chart alongside the alternatives you reviewed (retreatment, surgery, extraction and replacement).
The periodontal finding also points to a practical priority. If periodontal progression is the most commonly reported reason periodontally indicated resections are eventually lost, the maintenance plan after resection is part of the treatment, not an afterthought. A resected molar that never returns for periodontal maintenance is a different case from one seen on a structured recall.
Pro Tip: Book the first periodontal maintenance visit before the patient leaves the resection appointment, and flag the tooth in your recall system so hygienists know to assess the furcation area specifically.
Finally, the review is a reminder of how to read pooled numbers. A single summary ratio can hide very different follow-up times. When a referral partner or a continuing-education speaker quotes a survival percentage for root resection, ask over what follow-up period, and for which indication.
Limits worth keeping in mind
- Only five studies compared both indications directly.
- Follow-up periods varied widely, and the pooled ratio is not standardized for time.
- Endodontic-indication failure causes come from a single study of 29 teeth.
- The authors rate overall certainty of evidence as very low.
None of this makes root resection a poor option. It means the choice still rests on case-by-case judgment: the remaining roots, restorability, periodontal support, and the patient's ability to maintain the area.
EBIKO Dental will continue monitoring endodontic and periodontal research relevant to Canadian dental teams. For instruments and clinical supplies, visit ebiko.ca.
Sources
- Sabeti MA, Wang A. Root Resection Outcomes in Permanent Molars by Endodontic Versus Periodontal Indication: A Systematic Review and Meta-Analysis. Journal of Endodontics, 2026. doi:10.1016/j.joen.2026.10.012 (Europe PMC record)
Frequently Asked Questions
Q: Do root resections fail more often when done for periodontal reasons than for endodontic reasons?
A 2026 systematic review in the Journal of Endodontics found no statistically significant difference in failure risk between the two indications (risk ratio 0.82, 95% CI 0.56 to 1.21). The authors rate the certainty of this evidence as very low, so the question remains open.
Q: When is root resection considered for a molar?
The review's authors describe it as a tooth-preserving option for selected molars when endodontic retreatment or apical surgery is not feasible, or when periodontal furcation involvement compromises maintainability.
Q: What was the most common reason periodontally indicated resections were lost?
In the studies of periodontally indicated resections, periodontal disease progression was the most frequently reported cause of extraction. That makes structured periodontal maintenance after resection an important part of the plan.