A systematic review and meta-analysis in the Journal of Endodontics pooled a 4- to 5-year survival estimate of 82.2% for root canal–treated cracked teeth, but the longer-term cohorts it reviewed report lower figures: 54% and 66% at 10 years, and 55% at 15 years in one Singapore cohort. Deep crack-associated probing was an established warning sign for extraction across multiple cohorts, and the authors rate the overall certainty of the evidence as very low.
Cracked teeth can make for difficult prognosis conversations. As of October 2026, a new review gives dentists in Toronto and across Canada a clearer, time-based way to frame that conversation. The headline is not that cracked teeth fail. It is that the answer to "how long will this last?" depends heavily on which time horizon you are asking about, and on a short list of clinical findings you can record at the chair.
What the new review studied
The paper, "Long-term Survival of Endodontically Treated Cracked Teeth: A Systematic Review and Meta-analysis," was published online in the Journal of Endodontics on 12 October 2026 (DOI 10.1016/j.joen.2026.10.002). Its two authors, C. Ruan and L. Wang, are affiliated with Sanming Integrated Medicine Hospital and Sanming University in Fujian, China. The full text sits behind a subscription, so everything reported here comes from the published abstract.
The authors set out to fix a specific gap. According to the abstract, earlier meta-analyses on this question "emphasized 1- to 5-year cohorts," and newer long-term data now allow what the authors call a "time-anchored reassessment." In plain terms: older pooled numbers mostly describe the first few years after treatment.
The search covered PubMed/Europe PMC, Embase and Web of Science from inception through 3 October 2026. Eligible studies were longitudinal cohorts of root canal–treated permanent cracked teeth with at least one year of follow-up, and the primary outcome was tooth survival. Two authors screened records and verified data independently.
- Studies included: 15, of which 9 contributed to the quantitative synthesis.
- What was pooled: published 4- to 5-year survival proportions, using a random-effects model.
- What was not pooled: longer horizons and prognostic factors, which the authors summarised narratively.
- Risk of bias: assessed with ROBINS-E-informed domains.
How long do root canal–treated cracked teeth survive?
The pooled 4- to 5-year survival estimate was 82.2%, with a 95% confidence interval of 67.7% to 91.1%, drawn from seven cohorts. Note the width of that interval and the reported heterogeneity (I² = 89.5%). The cohorts disagreed substantially with one another, and the authors conclude that survival "varies by setting."
Beyond five years the evidence thins out, and the numbers fall. Two independent cohorts reported 10-year survival of 54% and 66%. The second of those, a Singapore cohort, also reported 55% survival at 15 years.
That gap between the five-year and ten-year figures is the practical message. A patient who hears "about four in five of these teeth are still there at five years" may reasonably assume the tooth is good for life. The review's own conclusion pushes back on that: selected teeth "frequently remain functional for 4 to 5 years, but survival declines thereafter."
Pro Tip: When you discuss prognosis for a cracked tooth, quote the figure together with its time horizon ("at five years" versus "at ten years") and write both into the chart note. A single number without a timeframe is the version patients remember and later dispute.
Which findings predicted extraction?
The one risk indicator the abstract quantifies is deep probing associated with the crack. The authors describe it as "an established adverse marker across multiple cohorts." In the longest cohort they reviewed, the adjusted hazard of extraction was 2.48 for teeth with 4–5 mm crack-associated probing and 3.19 for probing of 6 mm or more.
The abstract lists several additional risk indicators:
- Radicular extension of the crack
- Periapical disease
- Multiple cracks
- Older patient age
- No definitive cuspal coverage
Of these, cuspal coverage is the one that depends on the restorative plan rather than on the tooth's condition at presentation. The abstract reports it as an association, not as proof that adding coverage improves survival. The rest are findings to measure, document and weigh before treatment.
The authors are careful about novelty. They state that deep crack-associated probing "is not a newly identified factor." What the review adds, in their words, is a quantification of "its persistent long-term association with extraction," integrated with radicular extension and restorative status.
Pro Tip: Record crack-associated probing depths at the deepest point, by site, at the initial examination. The review's strongest numbers are tied to probing categories (4–5 mm and 6 mm or more), so a chart note that just says "crack present" gives you nothing to compare against later.
How strong is the evidence?
This is the part to read twice before quoting any number to a patient. The authors rate every included study at serious risk of bias and the overall certainty of evidence as very low. The 10- and 15-year figures come from individual cohorts rather than a pooled estimate, and the pooled 4- to 5-year figure carries high heterogeneity.
None of that makes the review useless. It makes it a good map of what is known and a poor source for precise predictions about an individual tooth. The authors' own recommendation is that prognosis "should be time-dependent and individualized."
What this means for Canadian dental practices
The review offers general dentists and endodontists in Toronto, the GTA and the rest of Ontario firmer language for three everyday situations.
Treatment planning conversations
When a patient is choosing between root canal treatment with a crown, extraction with an implant, or extraction alone, the honest framing is now easier to state: many selected cracked teeth do well for several years, survival drops over the following decade, and specific findings (deep probing, a crack running onto the root, multiple cracks) are associated with a worse outlook. Presenting the time horizon openly sets expectations for the years after the first five.
Referral and documentation
For general dentists referring to an endodontist in Mississauga, Markham or downtown Toronto, the risk list doubles as a referral checklist. Including probing depths, crack location and extent, periapical status and the planned restoration in the referral letter gives the specialist what they need to give a time-anchored prognosis of their own.
Restoring the tooth after endodontic treatment
Lack of definitive cuspal coverage is one of the risk indicators the review names. Because the abstract does not specify restoration types or timing, it is not a basis for a particular protocol. It is, however, a reminder that the restorative plan belongs in the same conversation as the root canal, not in a separate appointment months later.
Pro Tip: Add a line to your informed-consent notes for cracked teeth that names the patient-specific risk findings you observed. If the tooth is lost at year seven, a note showing the patient understood the risks is far more useful than a general statement that "risks were discussed."
EBIKO Dental will continue monitoring endodontic research for findings that affect how Canadian practices treat and restore compromised teeth. For more clinical news and supplies, visit ebiko.ca.
Sources
- Ruan C, Wang L. Long-term Survival of Endodontically Treated Cracked Teeth: A Systematic Review and Meta-analysis. Journal of Endodontics, published online 12 October 2026. doi:10.1016/j.joen.2026.10.002
- Europe PMC record (PMID 42863660): europepmc.org/article/MED/42863660
Frequently Asked Questions
Q: How long does a cracked tooth last after a root canal?
A 2026 meta-analysis in the Journal of Endodontics pooled a 4- to 5-year survival estimate of 82.2% for selected root canal–treated cracked teeth. Longer-term cohorts reported lower figures: 54% and 66% at 10 years, and 55% at 15 years in one Singapore cohort. The authors rate the certainty of this evidence as very low.
Q: What makes a cracked tooth more likely to need extraction after a root canal?
The review describes deep crack-associated probing as an established warning sign across multiple cohorts. In the longest cohort, adjusted extraction hazards were 2.48 for 4–5 mm probing and 3.19 for 6 mm or more. Radicular extension, periapical disease, multiple cracks, older age and no definitive cuspal coverage were also listed as risk indicators.
Q: Is the 82% 4- to 5-year survival figure reliable?
Treat it as a rough guide. All included studies were at serious risk of bias, the pooled estimate had a wide confidence interval (67.7% to 91.1%) and high heterogeneity, and the authors recommend individualised, time-dependent prognosis rather than a single number.