Endodontic retreatment:Post-operative pain in single or multiple visits


Root canal treatment is a commonly performed dental procedure, but treatment failure does occur. Non-surgical endodontic retreatment is one treatment option, and this may be carried out as a single or multiple visit procedure. Post-operative pain following endodontic retreatment has been reported in between 3-58% of patients and there is some debate as to whether this is more common in single or multiple visit approaches.

The aim of this review was to assess the postoperative pain after non- surgical endodontic retreatment in a one visit compared to multiple visits.


The review protocol was registered on the PROSPERO database and searches were conducted in the PubMed/Medline, Scopus, Cochrane Library and the OpenGey databases with no language restrictions. This was supplemented by searches in the journals, Journal of Endodontics, International Endodontic Journal, Clinical Oral Investigations, Journal of Dentistry, Journal of Investigative and Clinical Dentistry, and Brazilian Oral Research.

Randomised clinical trials (RCTs) assessing postoperative pain in non-surgical endodontic retreatment of one visit or multiple visits using analogue scale pain assessment with follow up of 4 weeks were considered.  Two reviewers independently selected studies, extracted the data and assessed risk of bias using the Cochrane tool. Post-operative pain was measured at 1,2,7 and 30 days and meta-analyses conducted. Overall certainty of the evidence was assessed using e Grading of Recommendations, Assessments, Development, and Evaluations (GRADE) approach.


  • 4 RCTs involving a total of 472 patients were included.
  • One study involved single rooted teeth, one study multiple rooted teeth only with 2 studies using both tooth types.
  • 2 studies reported the use of analgesics post treatment.
  • 3 studies were at high risk of bias and one at unclear risk.
  • Meta-analyses were conducted for the risk of any, mild, moderate and sever postoperative pain (see tables).
No. of studies Any post-operative pain Risk ratio (95%CI) Mild post-operative pain Risk ratio (95%CI)
1 day 2 0.67 (0.48 -0.93) 0.54 (0.30 – 0.96)
2 days 2 0.73 (0.11 – 4.98) 0.33 (0.12 – 0.88)
7 days 3 1.13 (0.60 – 2.13) 1.21 (0.70 – 2.09)
30 days 2 0.09 (0.01 – 1.25) 0.12 (0.02 – 0.86)


No. of studies Moderate post-operative pain Risk ratio (95%CI) Severe post-operative pain Risk ratio (95%CI)
1 day 1 1.24 (0.68 – 2.26) 0.09 (0.01 – 1.58)
2 days 2 2.16 (0.41 – 11.32) 1.16 (0.01 – 184.96)
7 days 2 1.12 (0.44 -2.86) 1.59 (0.37 – 6.77)
30 days 1 0.22 (0.01 – 4.01) 0.66 (0.03 – 15.92)
  • The overall GRADE certainty of the evidence was assessed a low.


The authors concluded: –

…limited evidence suggests that the endodontic retreatment in a one-visit visit has a similar postoperative pain to that of endodontic retreatment in multiple visits. Thus, due to the low number of studies and the heterogeneity of the data, further randomized clinical trials are recommended to provide better understanding of responses to both therapies.


The authors have searched a good range of databases supplementing this with a hand search of a number of relevant journals. Only RCTs have been considered meaning that only 4 studies met the inclusion criteria and none of the included studies were assessed as being at low risk of bias. A number of meta-analyses were performed for different pain outcomes at different time points but in some instances only single studies were included in the meta-analyses. This together with the quality of the studies should be taken into consideration when assessing the findings.

While this review has focused on endodontic retreatment it is worth nothing that an earlier Cochrane review (Dental Elf – 5th Dec 2016) of single verses multiple visits for initial non-surgical endodontic treatment also found no evidence to suggest that multiple visit root treatment was better than single visit treatment.


Primary Paper

Nunes GP, Delbem ACB, Gomes JML, Lemos CAA, Pellizzer EP. Postoperative pain in endodontic retreatment of one visit versus multiple visits: a systematic review and meta-analysis of randomized controlled trials. Clin Oral Investig. 2021 Feb;25(2):455-468. doi: 10.1007/s00784-020-03767-7. Epub 2021 Jan 5. PMID: 33399930.

Review protocol on PROSPERO

Other references

Dental Elf – 5th Dec 2016

Root canal treatment: single or multiple visits?

Dental Elf – 24th Oct 2016

Endodontic retreatment: Surgical or non-surgical approach?






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