Post Instrumentation Pain After the Use of Either Mtwo or the SAF System. A Randomized Controlled Clinical Trial

P. Saumya-Rajesh, J. Krithikadatta, N. Velmurugan, C. Sooriaprakas

Int Endod J. 2017. 50(8):750-760.


AIM: This randomized controlled trial compared the incidence of post-instrumentation pain associated with Mtwo rotary NiTi files and the Self-Adjusting file system following canal shaping and cleaning.

METHODOLOGY: Following sample size estimation, a total of 130 patients were randomized into two groups based on selection criteria [Group Mtwo; and Group SAF (Self-Adjusting File)]. Root canal treatment was carried out in two appointments. The teeth were endodontically treated with the appropriate allotted systems following similar clinical parameters. Participants were asked to rate the intensity of pre-instrumentation and post-instrumentation pain (at 2,4,6,8,24,48 hours) using the VAS score. The Kruskal- wallis test was done for overall comparisons of the two systems. The Friedman test was used to compare between time points with each system. Sub-group analyses for independent variables (gender, pulp status and diagnosis) used the Mann-Whitney test and Wilcoxon Signed Ranks test (P < 0.05).

RESULTS: No significant difference was found between the two groups in relation to post instrumentation pain. Teeth with pulpal necrosis had significant pain at 8 hours compared to teeth with vital pulps (P = 0.04). Teeth with vital pulps in the SAF group had significantly less post-instrumentation pain compared to the Mtwo group at 6 hours (P = 0.042). Patients with teeth with non-vital pulps in the SAF group experienced more post-instrumentation pain at 8 hours (P = 0.017) and 24 hours (P = 0.005)

CONCLUSION: The incidence of post-instrumentation pain at different time intervals in patients undergoing root canal treatment was similar for both the Self-Adjusting file and Mtwo file systems.


The full article is available online: Researchgate

Saumya Rajesh IEJ 2017


Additional Info

  • ReDent Nova’s note:

    Measuring post-operative pain in endodontics is a delicate issue, relating not only to technical aspects (i.e. the instrumentation technique) but also to psychological aspects - the patients' expectations, the way their participation in the research was presented to them, the way that they are questioned, etc.

    This research, basically, showed that there is little to no post-operative pain after endodontic instrumentation. This contradicts many researches that showed that such pain exists to a significant extent and relate it to the mode of instrumentation. Some examples to such researches: Bürklein et al., Int Endod J 2014; Gambarini et al. Ann Stomatol 2013; Arias et al. J Dent 2014; Nekoofar et al, J Endod 2015.

    Since the SAF System was shown in several researches to extrude significantly less debris than rotary instrumentation systems, further research is required to investigate this topic.

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  • View abstract on PubMed. PMID: 27662605