Single-visit or multiple-visit root canal treatment: systematic review, meta-analysis and trial sequential analysis

BMJ Open. 2017 Feb 1;7(2):e013115. doi: 10.1136/bmjopen-2016-013115.


Objectives: Single-visit root canal treatment has some advantages over conventional multivisit treatment, but might increase the risk of complications. We systematically evaluated the risk of complications after single-visit or multiple-visit root canal treatment using meta-analysis and trial-sequential analysis.

Data: Controlled trials comparing single-visit versus multiple-visit root canal treatment of permanent teeth were included. Trials needed to assess the risk of long-term complications (pain, infection, new/persisting/increasing periapical lesions ≥1 year after treatment), short-term pain or flare-up (acute exacerbation of initiation or continuation of root canal treatment).

Sources: Electronic databases (PubMed, EMBASE, Cochrane Central) were screened, random-effects meta-analyses performed and trial-sequential analysis used to control for risk of random errors. Evidence was graded according to GRADE.

Study selection: 29 trials (4341 patients) were included, all but 6 showing high risk of bias. Based on 10 trials (1257 teeth), risk of complications was not significantly different in single-visit versus multiple-visit treatment (risk ratio (RR) 1.00 (95% CI 0.75 to 1.35); weak evidence). Based on 20 studies (3008 teeth), risk of pain did not significantly differ between treatments (RR 0.99 (95% CI 0.76 to 1.30); moderate evidence). Risk of flare-up was recorded by 8 studies (1110 teeth) and was significantly higher after single-visit versus multiple-visit treatment (RR 2.13 (95% CI 1.16 to 3.89); very weak evidence). Trial-sequential analysis revealed that firm evidence for benefit, harm or futility was not reached for any of the outcomes.

Conclusions: There is insufficient evidence to rule out whether important differences between both strategies exist.

Clinical significance: Dentists can provide root canal treatment in 1 or multiple visits. Given the possibly increased risk of flare-ups, multiple-visit treatment might be preferred for certain teeth (eg, those with periapical lesions).

Keywords: Clinical outcomes; Clinical studies/trials; Comparative effectiveness research (CER); Endodontics; Evidence-based dentistry/health care; Systematic reviews and evidence-based medicine.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Humans
  • Office Visits*
  • Pain, Postoperative / etiology
  • Randomized Controlled Trials as Topic
  • Root Canal Therapy / adverse effects*
  • Root Canal Therapy / methods*
  • Symptom Flare Up