The Influence of Sodium Hypochlorite and Chlorhexidine on Postoperative Pain in Necrotic Teeth: A Systematic Review

Prevalence of postoperative pain after endodontic treatment using low and high concentrations of sodium hypochlorite: a systematic review and meta-analysis

OBJECTIVES

To determine the prevalence of postoperative pain after endodontic treatment using low (LC) and high (HC) concentrations of sodium hypochlorite (NaOCl).

MATERIALS AND METHODS

Six databases and the grey literature were searched to identify randomized clinical trials that evaluated postoperative pain after endodontic treatment using NaOCl. NaOCl concentrations were dichotomized into 'LC' (0.5% to 3%) and 'HC' (≥ 5%) and a proportion meta-analysis was applied to determine the postoperative pain prevalence: overall and according to pain intensity and postoperative time. The prevalence of patients using pain control medication was also determined. A significance level of 5% and a random effect model were applied for data analysis. Between-study heterogeneity was assessed by I2 index. Risk of bias (RoB) was assessed using the Cochrane Risk-of-Bias 2.0 tool. The certainty of evidence was assessed using the GRADE approach.

RESULTS

Ten studies were included in the review and eight in the meta-analysis. The overall prevalence of postoperative pain was 45% in LC and 39% in HC. The prevalence of pain in LC and HC after 24 h was 25% and 40%, respectively. After 48 h, the prevalence decreased to 10% in LC and 25% in HC. 'Absent pain' was the most prevalent score. The prevalence of patients who used medication was 9% in LC and 15% in HC. Three studies were classified as 'high RoB', five as 'low RoB', and two as 'some concerns'. The certainty of evidence was very low.

CONCLUSIONS

The overall prevalence of postoperative pain after endodontic treatment using LC and HC of NaOCl was 45% and 39%, respectively.

CLINICAL RELEVANCE

Postoperative pain is common after endodontic treatment using NaOCl, but tends to decrease over time.

What is the best effective postoperative medication in reducing pain after non-surgical root canal treatment?

Data sources Medline, Embase, CENTRAL, Cumulative Index to Nursing and Allied Health Literature and Scopus databases were searched (until July 31 2019). They searched the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov databases for completed and ongoing trials, as well as ProQuest, Google Scholar (first 100 hits) and the OpenGrey database for those unpublished. In addition, abstracts of annual meetings from the American Association of Endodontists, the International Federation of Endodontic Associations and the European Society of Endodontics were searched. A manual search of references in related papers and textbooks was carried out. Any missing information was filled in by contacting the authors.Study selection All randomised clinical trials (RCT) of nonsurgical endodontic therapy with pharmaceutical treatments provided postoperatively to alleviate pain on adult subjects were eligible. Two reviewers selected the studies and extracted the data and the results were examined by a third reviewer. Any differences were settled with the help of a fourth reviewer.Data extraction and synthesis Two authors independently evaluated and retrieved data from chosen trials found through searches. Another reviewer looked at the trial selection and data extraction. They also assessed the risk of bias in each of the research they chose.The mean and standard deviation of a 0-100 (mm) visual analogue pain scale were extracted or derived from study text, graphs and tables The postoperative medications were compared using network meta-analysis in a Bayesian model. Mean differences (MDs) and 95% credible intervals (CrIs) of post-operative pain were estimated at 6-8 hours and 12, 24 and 48 hours. Two authors utilised the CINeMA web application to assess the confidence in the main results by accounting for six domains: within- and across-study bias; indirectness; imprecision; heterogeneity; and incoherence. Each domain was assigned no concerns, major concerns, or minor concerns. Each result would be assigned a confidence level of high, moderate, low, or very low. To establish an agreement, a third reviewer was consulted.Results From the initial search of 969 records, 11 RCTs matched the inclusion criteria. Five studies were rated as having a low risk of bias, five as having a moderate risk and one as having a high risk. Moderate and major heterogeneity and some inconsistencies were detected, though not statistically significant.Oral medications were classified into placebo, non-steroidal anti-inflammatory drugs (NSAIDs), opioids, acetaminophen, NSAIDs + acetaminophen, corticosteroids, NSAIDs + benzodiazepines and NSAIDs + opioids groups.With moderate confidence, NSAIDs + acetaminophen were shown to be more efficacious than placebo at 6-8 hours following nonsurgical root canal therapy (MD = 22; 95% CrI = [-38, -7.2]). With very low confidence, NSAIDs had a greater effect than placebo after 12 and 24 hours (MD = -28; 95% CrI = [-49, -7] and MD = -15; 95% CrI = [-27, -2.3], respectively). After 6 12 and 24 hours, other medications were no more effective than placebo in pain reduction. After 48 hours, no treatment was more effective than placebo. Subgroup analysis found that other medications, such as corticosteroids and acetaminophen, were no more beneficial than placebo for patients who could not use NSAIDs. Six trials provided safety data and concluded that the therapies were safe and posed no significant risks.Conclusions Very low to moderate-quality evidence suggests that postoperative administration of NSAIDs and acetaminophen, or NSAIDs alone, reduced discomfort after non-surgical root canal therapy in patients with irreversible pulpitis or pulpal necrosis. Trials have shown, however, that using these drugs does not result in major complications. We cannot, however, be confident that they are risk-free.