Comparison of the Effect of Root Canal Preparation by Using WaveOne and ProTaper on Postoperative Pain: A Randomized Clinical Trial

Mohammad H. Nekoofar, DDS, MSc, DoIBoE, PhD , Mohammad S. Sheykhrezae, DDS, MSc, DoIBoE, Naghmeh Meraji, DDS, MSc, DoIBoE , Azad Jamee, DDS , Armin Shirvani, MD , Javid Jamee, PhD , Paul M.H. Dummer, BDS, MScD, PhD, DDSc, FDSRCS(Ed), FHEA

Most manufacturers of endodontic instruments claim that their instruments and recommended techniques are “the best” allowing practitioners to complete their treatment with fewer instruments and in less time. But what about the patients? Post-treatment pain is a consequence that can create increased anxiety and foster poor relations between practitioners and their patients who expect that the treatment they received was to eliminate their discomfort, not to prolong it.

In a paper published in the May 2015 issue of the Journal of Endodontics Nekoofar et al reported on a clinical trial that “was to compare the incidence and intensity of postoperative pain after use of the WaveOne system and the ProTaper Universal (Dentsply Maillefer) rotary system to prepare root canals in permanent human teeth.”

Both systems are manufactured by Dentsply Maillefer with WaveOne being a single-file reciprocating system and ProTaper Universal being a multi-file full rotation system.

The authors hypothesized “that preparation with WaveOne causes the same postoperative pain as ProTaper.”

They found, in this limited study,¬† that “(p)ostoperative pain lasted longer and was more intense in patients treated with the WaveOne system compared with the ProTaper Universal system.” Besides the differing effect that a reciprocating vs. a rotational motion may have on debris extrusion, the authors felt that an additional factor might be the fact that the WaveOne¬† technique is not used with coronal enlargement while in the ProTaper Universal system the Sx file used initially was primarily included for the purpose of coronal flaring. As it has been shown that the crown-down technique is associated with less debris extrusion compared with other instrumentation techniques “it is possible that early preflaring is associated with less debris extrusion and postoperative pain.”

The authors’ published abstract appears below.



WaveOne is a single-file reciprocating instrumentation system with the benefits of M-Wire alloy that has increased flexibility and improved resistance to cyclic fatigue over the conventional alloy. Root canal preparation techniques may cause postoperative pain. The goal of the present study was to compare the intensity and duration of postoperative pain when using WaveOne or ProTaper Universal systems for instrumentation of root canals.


Forty-two patients who fulfilled specific inclusion criteria were assigned to 2 groups according to the root canal instrumentation technique used, WaveOne or ProTaper Universal. Root canal treatment was carried out in 2 appointments, and the severity of postoperative pain was assessed by numerical rating scale (NRS) score after each session until complete pain relief was achieved. Analgesic consumption, duration of pain, and root canal preparation time were also recorded.


The mean NRS score and duration of pain after both appointments were significantly higher in the WaveOne group (P < .05); however, the mean analgesic consumption was only significantly higher in the WaveOne group after the first appointment (P < .05). In all groups the highest mean NRS score was seen 6 hours after each therapeutic appointment. Canal preparation time was significantly shorter in the WaveOne group (P < .001).


Postoperative pain was significantly lower in patients undergoing canal instrumentation with ProTaper Universal rotary instruments compared with the WaveOne reciprocating single-file technique.

Dr. Barry H. Korzen

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