During root canal therapy (RoCT) cleaning and shaping of the canals using irrigant solutions is considered to play an important role in successful treatment. Sodium hypochlorite (NaOCl) is the most widely used irrigant although chlorhexidine gluconate (CHX), which has good antiseptic properties, is a promising alternative.

The aim of this review was to assess of the effectiveness of NaOCl and CHX for root canal disinfection during root canal therapy

Methods

Searches were conducted in the Medline, Web of Knowledge, SCOPUS, and Science Direct databases. Clinical trials and randomized controlled trials published in English and comparing CHX and NaOCl as irrigant agents during root canal treatment were considered. Two reviewers carried out study selection and data abstractions independently. Study quality was assessed using items from the CONSORT statement. Owing to the heterogeneity of the laboratory methods used meta-analysis was not conducted.

Results

• 5 studies were included (4 RCTs, 1 CT).
• Sample sizes varied from 20 to 54 patients.
• Only single rooted teeth were included in the studies.
• NaOCl concentrations were tested at 2.5% and 5.25%.
• CHX was evaluated using 0.12%, 0.2%, and 2%
• There was a lack of agreement between the studies
  • 1 study reported NaOCl at 2.5% was more effective than CHX at 2%.
  • 1 study that CHX at 2% was more effective than NaOCl at 5.25%.
  • 2 studies reported that NaOCl at 2.5% and CHX at 0.2% and 0.12% were effective in reducing the levels of bacterial in infected root canals.
  • 1 reported that NaOCl at 2.5% and CHX gel at 2% were not effective in eliminating endotoxin from the primarily infected root canals.

Conclusions

The authors concluded:

The available evidence on this topic is scarce, and the findings of studies were not consistent. Additional randomised clinical trials using clinical outcomes to compare the use of sodium hypochlorite and chlorhexidine during root canal therapy are needed.

Comments

This review set out to compare the efficacy of two root canal irrigants used during RoCT. A 2012 Cochrane review by Fedorowicz et al (Dental Elf – 13^th Sept 2012 ) has previously looked at this topic. They included 11 RCTs, four of which compared NaOCL and CHX. This new review also includes 4 RCTs only 2 of which were included in the 2012 Cochrane review. The Cochrane review concluded:-

Although root canal irrigants such as sodium hypochlorite and chlorhexidine appear to be effective at reducing bacterial cultures when compared to saline, most of the studies included in this review failed to adequately report these clinically important and potentially patient-relevant outcomes. There is currently insufficient reliable evidence showing the superiority of any one individual irrigant. The strength and reliability of the supporting evidence was variable and clinicians should be aware that changes in bacterial counts or pain in the early postoperative period may not be accurate indicators of long-term success. Future trials should report both clinician-relevant and patient-preferred outcomes at clearly defined perioperative, as well as long-term, time points.

This new review has not identified any RCTs published since 2012 so there is currently no evidence to suggest whether NaOCl or CHX should be the irrigant agent of choice during endodontic therapy.

Links

Primary paper

The Effect of Sodium Hypochlorite and Chlorhexidine as Irrigant Solutions for Root Canal Disinfection: A Systematic Review of Clinical Trials Lucio Souza Gonçalves, Renata Costa Val Rodrigues, Carlos Vieira Andrade Junior, Renata G. Soares, Mario Vianna Vettore

Other references

Dental Elf – 13^th Sep 2012 – Insufficient reliable evidence showing the superiority of any one individual irrigant agent for use during root canal treatment

Dental Elf- 20^th Jun 2013 – Review finds limited evidence for predisposing factors for irrigant extrusion during root canal treatment

Dental Elf – 10^th Jun 2014 – Only limited evidence on the use of photodynamic therapy in root canal disinfection