Pain following root canal treatment has been reported In 1.5 – 53% of patients and is a cause of concern for them and clinicians. Studies have been conducted into a number of strategies to reduce post-operative endodontic pain including pharmacological approaches, intracanal medication and occlusal reduction. Recently a number of trials have examined the use of intracanal cryotherapy.
The aim of this review was to evaluate the effect of intracanal cryotherapy in reducing postoperative pain after instrumentation or obturation in root canal treatment in patients with pulpal or periradicular pathosis.
Methods
The review protocol was registered with PROSPERO and followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) principles . Searches were conducted in the PubMed, Embase, Scopus, and the Cochrane Library databases. This was supplemented by hand searches of the journals, Journal of Endodontics, the International Endodontic Journal, and the Australian Endodontic Journal. Only randomised controlled trials (RCTs) were considered the primary outcome being postoperative pain from the first day until the seventh day with rescue medication and adverse effects as secondary outcomes. Two reviewers independently assessed eligibility and risk of bias using the Cochrane tool and extracted data. Mean differences (MDs) with 95% confidence intervals (CIs) were used to assess outcomes and random effects meta-analysis conducted. The quality of evidence for each outcome was assessed using the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) system.
Results
- 8 RCTs involving 810 patients were included.
- 2 studies had low risk of bias in all domains with 6 being at high risk of bias in two or more domains.
- 6 studies contributed to the meta-analyses.
| Post-operative pain at | No. of studies
(patients) |
MD (95%CIs) | GRADE |
| 6 hrs | 4 (380) | -1.37 (-0.61 to -2.14)* | Moderate |
| 24hrs | 6 (593) | -1.43 (-0.70 to -2.15)* | Moderate |
| 48 hrs | 3 (170) | -0.67 (0.12 to -1.46) | Low |
| 72 hrs | 2 (253) | -2.99 (2.49 to -8.48) | Low |
| 7 days | 2 (83) | -1.64 (1.57 to -4.86) | Very Low |
*statistically significant difference
- 2 out of 3 studies comparing analgesic use reported significantly less analgesic use in the intracanal cryotherapy group.
- No adverse events were reported in any study.
Conclusions
The authors concluded: –
Moderate-quality evidence suggests that intracanal cryotherapy in the form of cold saline irrigation as the final irrigant significantly reduces pain between 6 and 24 hours after root canal therapy. Intracanal cryotherapy may also reduce the need for rescue medication. Well-designed trials assessing the effectiveness of cryotherapy in patients with severe preoperative pain, symptomatic apical periodontitis, and the long-term success of intracanal cryotherapy are warranted.
Comments
This well conducted systematic review has searched 4 major databases identifying 8 RCTs. However only 2 of the included studies were at low risk of bias in all domains. While the findings suggest that the use of intracanal cryotherapy reduced post-operative pain significantly at 6 and 24 hrs. While this is a relatively simple intervention the authors note that the optimal dosage and duration has not been determined although most studies used 20 mL cold saline at 2.5°C for 5 minutes. The findings suggest that intracanal cryotherapy may be of benefit in reducing the use of rescue medication so this and the impact of intracanal cryotherapy in patients with apical periodontitis and those severe preoperative pain in future well conducted studies
Links
Primary Paper
Sadaf D, Ahmad MZ, Onakpoya IJ. Effectiveness of Intracanal Cryotherapy in Root Canal Therapy: A Systematic Review and Meta-analysis of Randomized Clinical Trials. J Endod. 2020 Dec;46(12):1811-1823.e1. doi: 10.1016/j.joen.2020.08.022. Epub 2020 Sep 8. PMID: 32916207.
Other references
Dental Elf – 28th Aug 2020
Dental Elf – 4th Feb 2020
Post-endodontic pain: Is it influenced by concentration of sodium hypochlorite irrigation?
Dental Elf – 25th Jun 2018
Dental Elf – 18th Jun 2018
