Non-Cochrane · prognostic · PM42026978
Factors Associated With Endodontic Flare-Ups: A Systematic Review and Meta-Analysis.
Ohshima Jun, Morita Masayoshi, Kawanishi Yuzo, et al. · International endodontic journal · 2026 · PubMed · doi:10.1111/iej.70164
Findings
Population Patients undergoing root canal treatment (mature teeth)
17 findings
| Age 50 years or older (exposure) | Age 49 years or younger | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 1.3 [0.84, 2.0] Very low Downgraded: risk of bias, imprecision, inconsistency 11 studies · 13071 participants |
| Female sex (exposure) | Male sex | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 1.53 [1.13, 2.08] Low Downgraded: risk of bias, inconsistency 13 studies · 16069 participants |
| Mandibular tooth (exposure) | Maxillary tooth | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 1.43 [1.21, 1.69] Moderate Downgraded: risk of bias 11 studies · 15677 participants |
| Non-vital pulp (exposure) | Vital pulp | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 2.18 [1.69, 2.82] Moderate Downgraded: risk of bias 11 studies · 12959 participants |
| Preoperative spontaneous pain (exposure) | No preoperative spontaneous pain | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 5.83 [2.33, 14.59] Very low Downgraded: risk of bias, imprecision, inconsistency 3 studies · 2052 participants |
| Apical radiolucency (periapical lesion) (exposure) | No apical radiolucency | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 2.49 [1.85, 3.36] Low Downgraded: risk of bias, inconsistency 11 studies · 20267 participants |
| Multiple-visit treatment (exposure) | Single-visit treatment | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 2.34 [1.34, 4.06] Low Downgraded: risk of bias, inconsistency 9 studies · 17462 participants |
| Re-treatment (exposure) | Initial treatment | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 1.64 [1.18, 2.29] Moderate Downgraded: risk of bias 9 studies · 15077 participants |
| Preoperative percussion pain (exposure) | No preoperative percussion pain | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 3.45 [2.22, 5.38] Low Downgraded: risk of bias, inconsistency 3 studies · 8020 participants |
| Multiple root canals (exposure) | Single root canal | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 0.99 [0.74, 1.33] Low Downgraded: risk of bias, imprecision 3 studies · 4544 participants |
| Stainless steel hand files (exposure) | NiTi rotary files | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 1.85 [0.82, 4.16] Low Downgraded: risk of bias, imprecision 3 studies · 7694 participants |
| Preoperative analgesic use (exposure) | No preoperative analgesic use | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 2.5 [0.68, 9.18] Very low Downgraded: risk of bias, imprecision, inconsistency 3 studies · 2739 participants |
| Anterior teeth (exposure) | Other teeth | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 1.06 [0.85, 1.31] Moderate Downgraded: risk of bias 12 studies · 19571 participants |
| Premolars (exposure) | Other teeth | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 0.85 [0.67, 1.08] Moderate Downgraded: risk of bias 12 studies · 19571 participants |
| Molars (exposure) | Other teeth | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment · Hartung-Knapp adjustment (sensitivity analysis) | RR 1.21 [0.991, 1.472] GRADE not reported 12 studies · 19571 participants |
| Molars (exposure) | Other teeth | Clinically significant endodontic flare-up (severe pain and/or swelling requiring an unscheduled visit and additional treatment within about 1 week) Within about 1 week after root canal treatment | RR 1.21 [1.001, 1.457] Moderate Downgraded: risk of bias 12 studies · 19571 participants |
| Root canal treatment | None | Overall incidence of clinically significant flare-ups Within about 1 week after root canal treatment | Incidence (%) 2.83 GRADE not reported 15 studies · 24320 participants |
Included primary studies 15
Open in Studies| Study | Year | Also included by | Outcomes it informs here | Trial data |
|---|---|---|---|---|
| Alves 2010 Endodontic flare-ups: a prospective study. PMID:20813556 | 2010 | this review only | not stated | not extracted yet |
| Azim 2017 Prevalence of inter-appointment endodontic flare-ups and host-related factors. PMID:27179654 | 2017 | this review only | not stated | not extracted yet |
| Chen 2007 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Cheng 2006 Incidence and factors associated with endodontic inter-appointment emergency in a dental teaching hospital in China. PMID:16414172 | 2006 | this review only | not stated | not extracted yet |
| Imura 1995 Factors associated with endodontic flare-ups: a prospective study. PMID:8626209 | 1995 | this review only | not stated | not extracted yet |
| Iqbal 2009 Incidence and factors related to flare-ups in a graduate endodontic programme. PMID:19134037 | 2009 | this review only | not stated | not extracted yet |
| Magar 2022 The Determination of Flare-Up Incidence and Associated Risk Factors During Endodontic Treatment: An Observational Retrospective Study. PMID:36523703 | 2022 | this review only | not stated | not extracted yet |
| Makanjuola 2018 Comparison of the incidence of flare-up and time efficiency in single visit root canal treatment employing either rotary or manual… PMID:30027921 | 2018 | this review only | not stated | not extracted yet |
| Mor 1992 Incidence of interappointment emergency associated with endodontic therapy. PMID:1289477 | 1992 | this review only | not stated | not extracted yet |
| Nair 2017 Incidence of Endodontic Flare-ups and Its Related Factors: A Retrospective Study. PMID:28852632 | 2017 | this review only | not stated | not extracted yet |
| Nosrat 2023 Flare-ups After Nonsurgical Retreatments: Incidence, Associated Factors, and Prediction. PMID:37451334 | 2023 | this review only | not stated | not extracted yet |
| Onay 2015 The evaluation of endodontic flare-ups and their relationship to various risk factors. PMID:26577095 | 2015 | this review only | not stated | not extracted yet |
| Pamboo 2014 Incidence and factors associated with flare-ups in a post graduate programme in the indian population. PMID:25674318 | 2014 | this review only | not stated | not extracted yet |
| Tanalp 2013 Cross-sectional evaluation of post-operative pain and flare-ups in endodontic treatments using a type of rotary instruments. PMID:22905970 | 2013 | this review only | not stated | not extracted yet |
| Walton 1992 Endodontic interappointment flare-ups: a prospective study of incidence and related factors. PMID:1402571 | 1992 | this review only | not stated | not extracted yet |
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | Patients undergoing root canal treatment; paediatric patients and immature teeth excluded | 24,320 root canal treatment cases in 15 studies |
| Intervention | Patient-, tooth-, preoperative symptom- and treatment-related factors (risk factors) | 13 risk factors meta-analysed (age, sex, tooth position, pulp condition, spontaneous pain, periapical lesions, number of visits, re-treatment, number of canals, file type, percussion pain, tooth type, analgesic use) |
| Comparison | Absence of the factor | Absence of the factor or reference category |
| Outcomes | Endodontic flare-up: pain and/or swelling requiring an unscheduled emergency visit and additional treatment within approximately 1 week | Flare-up incidence (688 events, 2.83%); pooled risk ratios |
| Study designs | Observational or interventional studies reporting flare-ups after root canal treatment as primary outcome | 1 RCT, 4 prospective observational and 10 retrospective observational studies |
| Timing | Approximately 1 week after treatment | Mostly within 7 days; one study 14 days |