Root canal treatment is a routine procedure and is increasingly being carried out as a single -visit procedure. However, post-operative pain is still common being reported to occur in 3-58% of cases. The mechanism of post-operative pain remains unclear but may result from inadequate instrumentation, extrusion of irrigation solutions, intra-canal dressing or apical debris, missed canals,periapical pathosis or preoperative pain. Studies have also suggested that instrument choice may play a role.
The aim of this review is to compare the postoperative pain after single-visit root canal treatment using manual and rotary instruments. The second objective was to compare the postoperative pain after single-visit root canal treatment using rotary and reciprocating instruments
Methods
Searches were conducted in the PubMed, Embase, Cochrane Library and Web of Science databases Randomised controlled trials (RCTs) prospective or retrospective controlled trial comparing different type of root canal instrumentation where outcome measures included incidence or intensity of post-operative pain percentage of analgesia used and dosage were considered. Two reviewers independently selected studies abstracted data and assessed risk of bias using the Cochrane tool. meta-analysis was conducted when two or more of the selected studies adopted similar indexes.
Results
- 17 studies were included, 9 for the first outcome and 12 for the second outcome.
- None of the studies was considered to be at low risk of bias, 16 were at unclear risk and 1 at high risk.
- Manual versus rotary instruments [9 studies]
- 2 studies reported a higher frequency of post treatment analgesic use in the manual group
- Meta-analysis indicated a significantly lower incidence of postoperative pain in the rotary files groups (RR, 0.32; 95% CI, 0.17–0.61; p = .0005) [5 studies].
- Meta-analysis [6 studies] indicated a significantly lower pain intensity with rotary instruments than with manual instruments at 6 or 8 hr,12hr and 24hrs.
| Pain Intensity | Standardised Mean Difference (95%CI) |
| 6 or 8 hr | −1.92; (−2.81 to −1.03) |
| 12hr | −2.47; (−3.26 to −1.68) |
| 24hrs | −1.86; (−2.54 to −1.19) |
- Rotary versus reciprocating instruments [12 studies]
- A sub-group meta-analysis suggested that multiple rotary-file systems contributed to a lower incidence of postoperative pain than did reciprocating single- file systems (RR, 0.73, 95% CI, 0.63–0.85, p < .0001 [ 4 studies].
- 5 studies reported a lower intensity of postoperative pain after root canal treatment with rotary files than with reciprocating files while 4 reported a non-significant difference and two studies reported a higher pain intensity.
- 2 studies reported on analgesic use reporting no difference between rotary and reciprocating groups.
Conclusions
The authors concluded: –
the results of the present study showed that the use of rotary instruments contributed to lower incidence and intensity of postoperative pain than hand files in patients who received single-visit root canal treatment. In addition, the use of multiple rotary-file systems contributed to a lower incidence of postoperative pain than did reciprocating systems. Further high-quality studies comparing the pain intensity after the use of rotary versus reciprocating systems are required to obtain a more convincing conclusion.
Comments
The authors have searched a good range of databases selecting 17 studies ,10 of which they have used to undertake a number of meta-analyses. While they have provided an overview of the characteristics of the included studies they have not indicated the study designs in their table. The risk of bias assessment suggests that only 6 of the included studies were randomised controlled trials and none of the studies were of high quality. Last year a study by Hou & Hou compared post-endodontic pain after single-visit root canal preparation with rotary vs reciprocating instruments and included 3 RCTs all of which are included in the current review.
This study found that manual instruments resulted in more pain than rotary instruments. The findings also support those of the Hou & Hou review in that rotary instruments resulted in less pain than reciprocating instruments. However, the quality of the available evidence is low so it needs to be interpreted cautiously.
Links
Primary Paper
Sun C, Sun J, Tan M, Hu B, Gao X, Song J. Pain after root canal treatment with different instruments: A systematic review and meta-analysis. Oral Dis. 2018 Mar 7. doi: 10.1111/odi.12854. [Epub ahead of print] Review. PubMed PMID: 29516592.
Other references
Hou XM, Su Z, Hou BX. Post endodontic pain following single-visit root canalpreparation with rotary vs reciprocating instruments: a meta-analysis of randomized clinical trials. BMC Oral Health. 2017 May 25;17(1):86. doi:10.1186/s12903-017-0355-8. PubMed PMID: 28545437; PubMed Central PMCID:PMC5445416.
