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 Table of Contents  
Year : 2020  |  Volume : 32  |  Issue : 4  |  Page : 175-180

Comparative evaluation of different instrumentation techniques on post endodontic pain in single visit root canal treatment: A randomized controlled trial

Department of Conservative Dentistry and Endodontics, I T S Dental College, Hospital and Research Centre, Greater Noida, Uttar Pradesh, India

Date of Submission22-Jan-2020
Date of Decision06-Feb-2020
Date of Acceptance13-Mar-2020
Date of Web Publication18-Jan-2021

Correspondence Address:
Dr. Anchal Aggarwal
Department of Conservative Dentistry and Endodontics, I T S Dental College, Hospital and Research Centre 47, Knowledge Park III, Greater Noida, Uttar Pradesh 201 308
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/endo.endo_11_20

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Background: Postendodontic pain (PEP) is defined as pain of any degree that occurs after the initiation of randomized controlled trial. The development of postoperative pain is usually due to acute inflammatory response in the periradicular tissues.
Aim: The aim of the study was to evaluate and compare the influence of different instrumentation techniques on PEP following a single-visit root canal treatment.
Materials and Methods: Ninety-nine patients were divided into three groups (99 = 33 × 3): Group 1, Control (ProTaper Universal Hand); Group 2, Rotary (ProTaper Universal Rotary); and Group 3, Reciprocating (WaveOne Gold). A Visual Analog Scale questionnaire was given at the end of the appointment to be filled at 6, 12, 24, and 48 h.
Results: Group 2 (Rotary technique) (ProTaper Universal Hand) showed minimum PEP with a mean pain score of 2.0 at the end of 48 h, which was statistically significant (P < 0.0001).
Conclusion: Different instrumentation techniques/systems used for biomechanical preparation had an effect on PEP. Minimum PEP was reported by patients in Group 2 (ProTaper Universal Rotary) when compared with those in Group 3 (WaveOne Gold) and Group 1 (ProTaper Universal Hand).

Keywords: Postendodontic pain, rotary instrumentation, single-visit endodontics

How to cite this article:
Aggarwal A, Dewan R. Comparative evaluation of different instrumentation techniques on post endodontic pain in single visit root canal treatment: A randomized controlled trial. Endodontology 2020;32:175-80

How to cite this URL:
Aggarwal A, Dewan R. Comparative evaluation of different instrumentation techniques on post endodontic pain in single visit root canal treatment: A randomized controlled trial. Endodontology [serial online] 2020 [cited 2022 Jul 5];32:175-80. Available from: https://www.endodontologyonweb.org/text.asp?2020/32/4/175/307309

  Introduction Top

Postendodontic pain (PEP) is defined as pain of any degree that occurs after the initiation of randomized controlled trial (RCT). The development of PEP is usually due to acute inflammatory response in the periradicular tissues. It commences within few hours or days after the treatment. However, it is a poor indicator of pathosis and an unreliable predictor of long-term success. It might undermine patients' confidence in their dentists or patient satisfaction with the treatment.[1] It is a paradox that though pain is the principal motivating factor for an individual to seek dental treatment, it is also an appreciable entity that dissuades the sufferer from cheerfully opting for a root canal treatment.[2]

Pain is an extremely subjective experience personally influenced by many factors, including, but not limited to, behavioral and cultural learning and expectations, attention response from surrounding people, physical (genetic) factors, and psychological factors. Quantifying and standardizing pain objectively across a group of individuals can be challenging. Numeric and verbal self-rating scales or behavioral observation scales have traditionally been used in clinical studies.[3]

Shaping and cleaning procedures are not easy to perform, due to anatomical complexities and limitations of the endodontic instruments, which often result in iatrogenic errors. In most cases, dentine chips, pulp tissue fragments, necrotic tissue, microorganisms, and intracanal irritants may be extruded from the apical foramen during canal instrumentation. Apical extrusion of infected debris to the periradicular tissues is one of the principal causes of PEP.[4]

Studies on debris extrusion using reciprocating and rotary files are controversial. Variability has been observed between different rotary systems in terms of debris extrusion, which can be due to differences in cross-sectional geometry, cutting blade design, taper, flute depth, tip and sequence of files, kinematics, and cutting efficacy. Furthermore, it has previously been suggested that the reciprocating movement per se might play a role in packing the debris into the irregularities of the root canal space, pushing them beyond the apical foramen. Different nickel–titanium (Ni–Ti) rotary systems may yield different patterns of neurogenic inflammation response in the periodontal ligament as a consequence of different amounts of irritant extruded from the root canal space.[5]

  Materials and Methods Top

The study protocol was approved by the research and ethics committee (Ref. No. ITSCDSR/L/2018/115). Ninety-nine male patients within the age group of 18–50 years were selected to take part in this clinical trial.

Nonvital maxillary and mandibular molars requiring RCT were selected for the study. A clinical examination was conducted that included thermal and electric pulp testing (heat and cold), percussion and palpation evaluation, periodontal probing, mobility assessment, and a periapical radiograph. All the past and present symptoms were noted. A diagnosis of irreversible pulpitis/pulpal necrosis was determined on the basis of the history and clinical and radiographic features.

The inclusion criteria included male patients in the age group of 18–50 years, asymptomatic nonvital maxillary and mandibular 1st and 2nd molars, periapical radiolucency of not more than 2 mm, teeth with no history of RCT, teeth with no pus or inflammatory exudate draining out of the canal, teeth with no sinus tract, and teeth with sound periodontal apparatus.

The exclusion criteria were female patients; patients who have consumed any type of analgesic at least 6 h prior to the treatment; patients with diabetes mellitus, hypertension, and other systemic diseases known to affect healing status; patients reporting for root canal retreatment; patients with known allergy to any of the drugs used in this study; teeth having internal or external resorption; teeth with open apices; and patients with moderate-to-advanced periodontal diseases.

A preoperative radiograph was taken to check the canals, periodontal tissues, and presence of periapical radiolucency. Patients were informed about the nature of the study, and an informed consent was taken before the treatment. The patients were then divided randomly into three groups based on the instrumentation technique, as follows: Group 1 (n = 33), Control (ProTaper Universal Hand, Dentsply Maillefer Company, USA); Group 2 (n = 33), Rotary (ProTaper Universal Rotary); and Group 3 (n = 33), Reciprocating (WaveOne Gold). All teeth were treated in a single appointment by the same operator.

Before the administration of the anesthetic, a test dose of 1:10 dilution of 2% lignocaine was administered intradermally on the forearm to determine if the patient was allergic to local anesthetic. Once it was determined that the patient was not allergic to the anesthetic, the root canal procedure was initiated. Each patient was anesthetized with a solution of 2% lidocaine HCl with 1:100,000 epinephrine. The tooth was isolated with a rubber dam. An occlusal reduction was performed, and coronal access was made using a sterile round bur (#2). The working length was determined, and the instrument was kept 0.5 mm short of the radiographic apex. After the establishment of working length, an initial glide path was established using a hand file. The root canals were instrumented for each group according to the manufacturer's instructions.

The canals were irrigated using 30G side-vented needles with sterile saline and 2.5% NaOCl after each instrument was used. The final irrigation was performed using 3 ml of 17% ethylenediaminetetraacetic acid. A volume of 5-ml solution was used for standardization. The canals were then dried using paper points. Obturation was done by lateral compaction method using zinc oxide eugenol sealer and gutta percha cones of different tapers according to the biomechanical preparation (BMP) done in the group. A temporary filling material was then placed, and patients were recalled after 48 h for postendodontic restoration.

A questionnaire was given to the patients at the end of the appointment, and patients were educated on how to assess and record the incidence and severity of pain at 6, 12, 24, and 48 h. Patients were asked to rate any pain occurring after endodontic procedure using the Visual Analog Scale (VAS). A rescue medication tablet ibuprofen 400 mg was prescribed to all the patients, and the examiner was asked to record it if consumed. Patients were recalled after 48 h with the filled questionnaire. Rating from the questionnaire was then tabulated. An illustration of how the trial was designed, analyzed, and interpreted is displayed in a flow diagram which presents the progress of all participants through the trial [Figure 1].
Figure 1: Flowchart of consort

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Statistical analysis

Data were entered into Microsoft Excel spreadsheet and were analyzed using the Statistical Package for the Social Sciences (SPSS) version 21 (IBM SPSS Statistics for Windows, version 21.0, Armonk, NY:IBM Corp.). VAS scores for pain were summarized as mean and standard deviation [Table 1].
Table 1: Comparison of mean pain scores between the three groups (n=33)

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Intergroup comparison of mean VAS scores was done using Kruskal–Wallis test along with post hoc pair-wise comparison by Mann–Whitney U-test. Intragroup comparison was done using Friedman test and Wilcoxon test. The level of statistical significance was set at 0.05 [Table 2].
Table 2: Intragroup and intergroup comparisons of Visual Analog Scale pain scores among the three different groups with the mean, median, and standard deviation

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  Results Top

Intragroup comparison of VAS scores for pain showed that the highest mean postoperative pain scores were observed 6-h post treatment in all the groups with a statistically significant decline thereafter (P < 0.05) [Figure 2] and [Table 2].
Figure 2: Graphical representation of the trends of pain with different instrumentation techniques of all groups at different time intervals

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To obtain intergroup comparison, the results were subjected to post hoc pair-wise comparison, in which Group 2 (Rotary technique) showed a statistically significantly lower mean VAS score when compared with Group 3 (Reciprocating technique), followed by Group 1 (Hand Filing technique) at all postoperative time points (P < 0.05) [Figure 3]. None of the 99 participants reported severe pain or flare-up during the period of the study.
Figure 3: Comparative analysis of the trends of pain between patients of all groups at different time intervals

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  Discussion Top

Pain of endodontic origin is widely feared due to its intensity. Pak and White showed that postobturation pain prevalence was 40% at 24 h, which reduced to 11% at 1 week. The severity of pain was substantially decreased within the first 2 days.[1] However, the etiology of PEP is multifactorial. Age, sex, tooth type or location, preoperative pain, periapical radiolucency, pulpal status, prophylactic drug, anesthetic agent, working length method, instrumentation, irrigation, use of lasers, obturation technique, occlusal reduction, postoperative drug, and operator contribute to PEP.[6]

In this study, only male patients were included to exclude any bias. Both maxillary and mandibular molars were selected as the literature does not reveal any difference in the PEP between the two. Single–visit treatment was chosen to maintain a simple uniform protocol and to rule out the potential influence of intracanal medication. VAS was used as a result of its ease, validity, and reliability to measure pain.[5] It provides a continuous scale for subjective magnitude estimation and consists of a straight line, the limits of which carry a verbal description of each extreme of the symptom to be evaluated. The line is usually 10 cm long and vertical. The failure of VAS is between 4% and 11%, but this can be reduced if the tool is carefully explained to the patient.[7]

In this study, 99 patients were divided into three groups as follows: Group 1 (ProTaper Universal Hand, n = 33), Group 2 (ProTaper Universal Rotary, n = 33), and Group 3 (WaveOne Gold, n = 33). ProTaper was selected in this study to assess the influence of variable taper along the length of the file in causing PEP. WaveOne reciprocating files were selected for this trial as a new intervention to evaluate the influence of motion kinematics for the reduction of PEP.[5] The unique design feature of WaveOne Gold is that each file has an alternating offset, parallelogram-shaped cross section. This design limits the engagement between the file and dentin to only 1 or 2 points of contact at any given cross section, subsequently reducing taper lock and the screw effect.[8]

From the results, the following observations were made at all given intervals of time (6, 12, 24, and 48 h):

Group 2 >Group 3 >Group 1.

Rotary technique >Reciprocating technique >Hand Filing technique.

Studies have demonstrated that all canal preparation techniques are associated with wide-ranging variability in debris extrusion depending on the mechanical systems used. This could be attributed to differences in the cross section, cutting-edge design, taper, tip type, configuration, concept of use, flexibility, alloy type, number of files used, kinematics, or cutting efficacy.

The pain associated with periradicular inflammation due to extrusion of debris may also be attributed to substance P and calcitonin gene-related peptide which activates G protein-coupled receptors on nociceptors, leading to the sensitization or activation of neurons, and these neuropeptides can cause peripheral sensitization characterized as hyperalgesia, allodynia, and spontaneous pain. Furthermore, central sensitization is initiated by a barrage in C-fiber inputs with sufficient intensity and duration.[9]

Minimum amount of pain occurred when ProTaper Rotary instrumentation was used. This could be because rotary system reduces the amount of extrusion of debris because the flutes of these instruments tend to pull debris back toward the orifice. Oppositely, in the manual step-back method, the file acts as a piston in the apical one-third, tending to plunge the debris through the apical foramen, leaving not enough space to expel it coronally; thus, it is more likely to cause inflammation and pain.[10]

Rotary instruments have been developed with symmetrical and asymmetrical rotary motions. The center of asymmetrical rotary instruments is positioned off-center relative to the instrument's central axis of rotation. During rotation, a mechanical wave of motion travels along the length of the working part of the instrument, which minimizes the contact between the file and dentin. In this case, rotary systems could yield cleaner canals with less debris accumulation than reciprocating instruments.[11]

The results of this study were in accordance with a study carried out by Bürklein and Schäfer,[12] who reported that full-sequence rotary instrumentation was associated with less debris extrusion compared with the use of reciprocating single-file systems, and suggested that this factor could be associated with less postoperative pain.

The results of this study are also similar to those of another study carried out by Gambarini et al.,[13] who compared the incidence and severity of postoperative pain after root canal treatment of necrotic teeth with RaCe rotary files and the single-file reciproc system. The results showed higher incidence and more severity of postoperative pain in the reciproc group, which was statistically significant.

According to Gambarini et al.,[14] two possible mechanisms can be responsible for an increased amount of extruded debris and consequently the more intense postoperative pain shown by the reciprocation instrumentation technique. First, the reciprocation movement is formed by a wider cutting angle and a smaller releasing angle. Second, the flutes will tend not to remove debris but to push some of them apically. The second mechanism is probably more relevant. It is well known that rotary Ni–Ti instruments perform best when using a crown-down technique, with the coronal part instrumented first and the apical part last. This strategy minimizes extrusion because the coronal parts of the canal have been cleaned and cleared before the apical part contents are addressed.

Moreover, the reciprocation technique uses a quite rigid, large, single file of increased taper (08 taper, size 25), which goes directly into the apex. In many cases, in order to reach the working length, reciprocating instruments are used with force directed apically to make an effective piston to propel debris from a patient's apical foramen.[15]

The results of this study are also similar to those of a study carried out by Pasquilini et al.[16] Patients' quality of life after treatment (including pain) was compared in two groups of patients undergoing treatment with the rotary technique (ProTaper) and the reciprocating system (WaveOne). Pain was significantly less in the rotary group.

However, in a study by Kherlakian et al.,[17] it was concluded that the reciprocating systems and the continuous rotary system were found to be equivalent with regard to the incidence of postoperative pain and intake of analgesic medication at the time points assessed.

The null hypothesis was thus rejected that there was no effect of different instrumentation techniques/systems on PEP.

  Conclusion Top

Within the limitations of this study, it was thus concluded that different instrumentation techniques/systems used for BMP had an effect on PEP. Minimum PEP was reported by patients, in which the BMP was done using Rotary technique (ProTaper Universal Rotary) when compared with Reciprocating (WaveOne Gold), followed by Hand Filing (ProTaper Universal Hand) techniques.

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Conflicts of interest

There are no conflicts of interest.

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El Mubarak AH, Abu-bakr NH, Ibrahim YE. Postoperative pain in multiple-visit and single-visit root canal treatment. J Endod 2010;36:36-9.  Back to cited text no. 1
Bhagwat S, Mehta D. Incidence of post-operative pain following single visit endodontics in vital and non-vital teeth: An in vivo study. Contemp Clin Dent 2013;4:295-302.  Back to cited text no. 2
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Attar S, Bowles WR, Baisden MK, Hodges JS, McClanahan SB. Evaluation of pretreatment analgesia and endodontic treatment for postoperative endodontic pain. J Endod 2008;34:652-5.  Back to cited text no. 3
Plotino G, Grande NM, Melo MC, Bahia MG, Testarelli L, Gambarini G. Cyclic fatigue of NiTi rotary instruments in a simulated apical abrupt curvature. Int Endod J 2010;43:226-30.  Back to cited text no. 4
Krithikadatta J, Sekar V, Sudharsan P, Velumurugan N. Influence of three Ni-Ti cleaning and shaping files on postinstrumentation endodontic pain: A triple-blinded, randomized, controlled trial. J Conserv Dent 2016;19:311-6.  Back to cited text no. 5
Nagendrababu V, Gutmann JL. Factors associated with postobturation pain following single-visit nonsurgical root canal treatment: A systematic review. Quintessence Int 2017;48:193-208.  Back to cited text no. 6
Jalalzadeh SM, Mamavi A, Shahriari S, Santos FA, Pochapski MT. Effect of pretreatment prednisolone on postendodontic pain: A double-blind parallel-randomized clinical trial. J Endod 2010;36:978-81.  Back to cited text no. 7
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Saha SG, Gupta RK, Bhardwaj A, Misuriya A, Saha MK, Nirwan AS. Comparison of the incidence of postoperative pain after using a continuous rotary system, a reciprocating system, and a self-adjusting file system in single-visit endodontics: A prospective randomized clinical trial. J Conserv Dent 2018;21:333-8.  Back to cited text no. 9
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Kashefinejad M, Harandi A, Eram S, Bijani A. Comparison of single visit post endodontic pain using Mtwo rotary and hand k-file instruments: A randomized clinical trial. J Dent (Tehran) 2016;13:10-7.  Back to cited text no. 10
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Bürklein S, Schäfer E. Apically extruded debris with reciprocating single-file and full-sequence rotary instrumentation systems. J Endod 2012;38:850-2.  Back to cited text no. 12
Gambarini G, Al Sudani D, Di Carlo S, Pompa G, Pacifici A, Pacifici L, et al. Incidence and intensivity of postoperative pain and periapical inflammation after endodontic treatment with two different instrumentation techniques. Eur J Inflamm 2012;10:99-103.  Back to cited text no. 13
Gambarini G, Gerosa R, De Luca M, Garala M, Testarelli L. Mechanical properties of a new and improved nickel-titanium alloy for endodontic use: An evaluation of file flexibility. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;105:798-800.  Back to cited text no. 14
Zand V, Milani AS, Hassani Dehkharghani A, Rahbar M, Tehranchi P. Treatment of necrotic teeth using two engine-driven systems and patient's postoperative pain: A double-blind clinical trial. Iran Endod J 2016;11:267-72.  Back to cited text no. 15
Pasqualini D, Corbella S, Alovisi M, Taschieri S, Del Fabbro M, Migliaretti G, et al. Postoperative quality of life following single-visit root canal treatment performed by rotary or reciprocating instrumentation: A randomized clinical trial. Int Endod J 2016;49:1030-9.  Back to cited text no. 16
Kherlakian D, Cunha RS, Ehrhardt IC, Zuolo ML, Kishen A, da Silveira Bueno CE. Comparison of the incidence of postoperative pain after using 2 reciprocating systems and a continuous rotary system: A prospective randomized clinical trial. J Endod 2016;42:171-6.  Back to cited text no. 17


  [Figure 1], [Figure 2], [Figure 3]

  [Table 1], [Table 2]


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