Root canal treatment done in single or multiple visits show comparable effectiveness Critical Summary Prepared by: Hope Saltmarsh RDH, BA, MEd; Ahmed Elkhadem BDS, MS 


  • Systematic Review Conclusion:

    No difference was found in effectiveness of root canal treatment with single vs. multiple visits, but treatment in a single visit results in slightly more frequent swelling and significantly more painkiller usage.

  • Critical Summary Assessment:

    This review found that single and multiple visit root canal treatments have similar outcomes, but because of evidence limitations, clinicians cannot predict which approach will have better outcomes for individual patients.

  • Evidence Quality Rating:


A Critical Summary of:

Single versus multiple visits for endodontic treatment of permanent teeth: a Cochrane systematic review

Figini L, Lodi G, Gorni F, Gagliani M. Journal of Endodontics. 2008;34(9):1041-7

  • Clinical Questions:

    In patients requiring root canal therapy, does single-visit treatment differ from multi-visit treatment in terms of effectiveness and incidence of complications?

  • Review Methods:

    The authors searched four databases for articles published from 1966 to March 2007. They also conducted a hand search. There were no language restrictions. They included randomized and quasi-randomized controlled trials of patients needing RoCT and excluded trials of patients requiring surgical endodontic treatment. Their main outcome measures included the number of teeth extracted for endodontic problems and radiological success after at least one year (i.e., the absence of any periapical radiolucency). Their outcome measures for complications were postoperative pain, swelling, analgesic use, fistula or sinus track formation.

  • Main Results:

    This systematic review included 12 studies. Authors performed meta-analysis if valid and relevant data were collected and the studies were sufficiently similar in design, population and intervention. Meta-analysis of five studies with 657 patients showed slightly fewer radiological failures with single visits, but this was not statistically significant when compared to multiple visits (relative risk [RR] 0.85; 95% confidence interval (CI), 0.59-1.23). A sub-analysis of patients with necrotic teeth (3 studies, 207 patients) showed, with close to statistical significance, that single visits had even fewer radiological failures. Meta-analysis of postoperative pain (six studies, 1,047 patients) as an outcome measure demonstrated no difference between single and multiple visits. Meta-analysis of three studies with 559 patients showed that analgesic use was significantly more common with single visits. Analysis of three studies with 192 patients showed swelling was more common with single visits, but was statistically insignificant.

  • Conclusion:

    This review found no difference in the effectiveness of RoCT, in terms of radiological success, between single and multiple visit treatments. Patients who undergo a single visit may experience a slightly higher frequency of swelling and are significantly more likely to take analgesics.

  • Source of funding:

    None reported.


  • Importance and Context:

    There is a current trend of completing RoCT in one visit instead of multiple visits. The success of RoCT depends on variables related to the preoperative condition of the tooth, as well as the endodontic procedures. This systemic review weighs the benefit/risk of single- and multiple-visit endodontic treatments. The benefits of single-visits are fewer patient visits per tooth; reduced incidence of interappointment leakage; immediate use of canal for retention of posts, particularly in the anterior region (aesthetic consideration); reduced procedural costs; decreased morbidity from repeat injections and rubber dam placement. The risks include increased postoperative pain, treatment failure resulting in removal of endodontic filling and retreatment, and extraction of the affected tooth. Studies comparing these treatment approaches offer conflicting conclusions.

  • Strengths and Weaknesses of the Systematic Review:

    The authors performed a comprehensive search of the literature. Two independent reviewers scanned and evaluated all search-identified titles and abstracts. Disagreements were resolved by discussion or by a third individual. They assessed study validity using established criteria. To eliminate assessment bias, two reviewers conducted a critical appraisal without concealing the names of authors, institutions, and medical journals. The authors provided a list of the included and excluded studies. The authors closely followed guidelines of AMSTAR (assessment of multiple systematic reviews). Reporting was complete.

  • Strengths and Weaknesses of the Evidence:

    A randomized controlled trial (RCT) is the best study design to answer a question about therapies. This systematic review included nine RCTs and three quasi-randomized controlled trials. The authors examined the validity of the studies based on allocation concealment and participant loss. Allocation concealment was inadequate in four studies (high risk of bias), unclear in four (moderate risk of bias), and adequate in four (low risk of bias). All studies met the acceptability criterion that at least 80 percent of the patients who entered trials were included in final analysis. Sensitivity analyses were performed excluding studies with high risk of bias and results remained unchanged. Effectiveness was the primary outcome. The included studies did not report the relevant patient-oriented outcomes of tooth extraction and fistula formation. As a surrogate measure of effectiveness, the authors considered the presence of periapical radiolucency after one year. However, only one of the five studies in the meta-analysis of radiological failure had extensive calibration of the evaluators. The pretreatment status of the 657 participants varied with regard to vital or necrotic pulp. The secondary outcomes reported were all binary (yes or no) patient-oriented measures of postoperative pain, swelling, and analgesic use. The meta-analysis of six studies (1,047 patients) showed no difference in postoperative pain for single versus multiple visits (RR 0.99) with a narrow confidence interval (CI) indicating precision despite the variability in study designs, quality, and pretreatment status. The large number of participants also reduces the likelihood that the results are due to chance. The authors used inconsistent metrics. Radiographically, there was no difference in effectiveness. The binary measure of pain showed no difference in postoperative pain. Yet, the most relevant patient-oriented outcome, analgesic use, was significantly more common in single visits.

  • Implications for Dental Practice:

    Since single and multiple visit RoCT do not differ in terms of treatment effectiveness, the selection of the technique to be used will depend on dentist expertise and patient needs. Clinicians should consider the need for analgesics when using the single visit approach.

  • Critical Summary Publication Date: 10/2/2010

These summaries are not intended to, and do not, express, imply, or summarize standards of care, but rather provide a concise reference for dentists to aid in understanding and applying evidence from the referenced systematic review in making clinically sound decisions as guided by their clinical judgment and by patient needs. American Dental Association ©

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