• Users Online: 566
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 

 Table of Contents  
Year : 2015  |  Volume : 5  |  Issue : 1  |  Page : 4-8

The effect of two continuous rotary and one reciprocating file systems on the incidence of postoperative pain after single-visit endodontic treatment

Department of Conservative Dentistry and Endodontics, College of Dental Sciences, Davangere, Karnataka, India

Date of Web Publication7-Dec-2015

Correspondence Address:
Rucha Nilegaonkar
Department of Conservative Dentistry and Endodontics, College of Dental Sciences, Davangere, Karnataka
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2231-6027.171165

Rights and Permissions

Aim: The aim of this study was to compare the amount of postoperative pain after using three different nickel–titanium file systems. Materials and Methods: Ninety patients with necrotic molar pulps were selected and divided into three groups. Group I (n = 30) was instrumented with ProTaper Next (PTN) file system, Group II (n = 30) was instrumented using WaveOne reciprocating system, and Group III (n = 30) was instrumented using Twisted File system. All canals were instrumented and obturated in the same visit. Postoperative pain response of patients was evaluated using the visual analogue scale (VAS) score. Results: For VAS pain scores, a statistically significant difference was found between the PTN and WaveOne technique (P = 0.000). Statistically significant difference was also found between the Twisted File and WaveOne technique (P = 0.002). Conclusion: It can be concluded that the difference in the postoperative pain is related to the instrumentation technique. Reciprocating system, WaveOne resulted in maximum pain followed by Twisted File and PTN file system.

Keywords: Continuous rotary systems, postoperative pain, reciprocating systems, root canal treatment

How to cite this article:
Shivanna V, Nilegaonkar R. The effect of two continuous rotary and one reciprocating file systems on the incidence of postoperative pain after single-visit endodontic treatment. Int J Oral Health Sci 2015;5:4-8

How to cite this URL:
Shivanna V, Nilegaonkar R. The effect of two continuous rotary and one reciprocating file systems on the incidence of postoperative pain after single-visit endodontic treatment. Int J Oral Health Sci [serial online] 2015 [cited 2022 Aug 18];5:4-8. Available from: https://www.ijohsjournal.org/text.asp?2015/5/1/4/171165

  Introduction Top

Endodontic treatment can be completed in either a single-visit or in multiple visits. It has been seen that patients generally tolerate and prefer single-visit endodontic therapy.[1],[2] Single-visit root canal treatment has become a common practice, which offers several advantages, including a decreased number of operative procedures [3] and decreased risk of inter-appointment leakage through temporary restorations.[1] As a consequence, innovative manufacturing processes to produce better instruments,[4],[5],[6],[7] and new instrumentation techniques have been recently commercialized to improve simplicity and safety of the treatment.[8],[9],[10]

DentsplyMaillefer (Baillagues, Switzerland) has developed a nickel-titanium instrument of greater taper - WaveOne, which is designed to be used with reciprocating motion and allow root canals to be prepared with one single instrument: In the majority of cases, a 0.08 taper, size 25 instrument is selected.[9],[10] However, there are studies indicating greater postoperative pain on using this reciprocating system.[9]

The fifth generation of shaping files has recently been introduced which consists of the ProTaper Next (PTN) system.[11] These files are used in continuous rotation. It is designed such that the center of mass of the file is offset from its center of rotation. Files that have an offset design produce a mechanical wave of motion that travels along the active length of the file. Like the progressive percentage tapered design of any given ProTaper file, this offset design serves to further minimize the engagement between the file and dentin.[11] In addition, an offset design enhances augering debris out of a canal and improves flexibility along the active portion of a PTN file (DENTSPLY Tulsa Dental Specialties).

SybronEndo has introduced the Twisted File system. This system utilizes continuous rotary motion and is available in a crown down sequence. The manufacturers have utilized the novel "R phase" heat treatment technology which has improved the mechanical properties of this file.[12]

This file system has a good cleaning efficiency which is comparable to that of the ProTaper rotary file system.[13]

It is well known that a small, inadvertent extrusion of debris and irrigants into periapical tissues occurs during the cleaning and shaping procedures, both with manual stainless steel and nickel–titanium rotary instrumentation techniques.[14],[15] However, studies have shown that reciprocating instrumentation techniques increase the amount of debris extruded beyond the apex, thus increasing the risk of postoperative pain.[16] A previous clinical study comparing reciprocating and NiTi rotary instruments has also confirmed these findings.[17] Based on these studies, goal of the present study was to evaluate and compare the incidence of postoperative pain using three different nickel–titanium instrumentation techniques: Two rotary techniques – the PTN and Twisted File system and a reciprocating single-file technique – the WaveOne system.

The null hypothesis was set as follows: There will be no difference in incidence of postoperative pain between PTN, Twisted File system, and WaveOne system.

  Materials and Methods Top

Ninety patients requiring endodontic treatment on permanent molar teeth with nonvital pulps were included in the study. Patients who had previously taken antibiotics or analgesics and those with preoperative pain were excluded. Radiographically, patients without periapical changes were selected. A diagnosis of pulp necrosis was made for each case based on the patient's symptoms and electric pulp test. A single clinician evaluated all patients using radiographic and clinical findings. The same clinician was assigned for treatment of all cases to eliminate or minimize interpersonal variability.

The patients were divided into three groups, each group consisting of 30 patients. After isolation and access, the canals of all teeth were prepared using three different instrumentation techniques. Irrigation was done using 5 ml, 5% sodium hypochlorite and 5 ml saline was done alternatingly after instrumentation with each file system. An irrigating needle of 30 gauge was used passively without forceful dispensing of the irrigant 1.5 mm short of its binding point. Intermittent agitation using a 15 number k file was done to prevent apical debris accumulation and coronoapical movements of the needle were done to agitate the irrigant manually. After completion of biomechanical preparation, canals were flushed with 5 ml saline. Final irrigant used was 5 ml of 17% ethylenediaminetetraacetic acid. The teeth in Group I (n = 30) were instrumented using PTN instruments, till master apical file number 25, 0.06%. Those in Group II (n = 30) were instrumented with a single-file technique, using WaveOne number 25, 8%. In Group III, canals were instrumented with Twisted Files, till master apical file number 25, 0.06%. Manufacturers' instructions were strictly followed during instrumentation of all the three file systems. After this, the canals were obturated with 25, 0.06% guttapercha cones and zinc oxide eugenol sealer using lateral condensation. All canals were shaped, cleaned, and obturated in a single visit.

After 3 days, the assessment of postoperative pain was carried out by one independent evaluator without knowledge of visit group under examination. The severity of pain was evaluated using a visual analogue scale (VAS) score, validated previously.[18]

  • No pain: The treated tooth felt normal. Patients do not have any pain
  • Mild pain: Recognizable, but not discomforting, pain which required no analgesics
  • Moderate pain: Discomforting, but bearable pain (analgesics if used, were effective in relieving the pain)
  • Severe pain: Difficult to bear (analgesics had little or no effect in relieving the pain).

VAS pain scores were compared using one-way ANOVA and post-hoc Tukey test. A value of P < 0.05 was required for statistical significance.

  Results Top

Results are shown in [Table 1]. For VAS pain scores, a highly statistically significant difference was found between PTN and WaveOne technique (P = 0.000). Statistically significant difference was also found between the WaveOne and Twisted File techniques (P = 0.002).
Table 1: Overall incidence of postoperative pain with ProTaper Next, WaveOne, and Twisted File systems

Click here to view

When comparing patients who developed no pain, PTN instrumentation technique showed significantly better results. When evaluating patients experiencing severe pain, the incidence of symptoms was significantly higher with the WaveOne single-file technique. Overall, severe pain occurred in 17.7% and no pain occurred in 22.2% patients.

  Discussion Top

Root canal preparation procedures often result in iatrogenic errors.[19],[20] Dentin chips, pulp tissue remnants, necrotic tissue, microorganisms, and endodontic irrigants may be extruded from the apical foramen during the canal instrumentation which may be related to the inflammation of periapical tissue, postoperative pain, and/or to a flare-up.[14],[15] Postoperative pain can be avoided using proper instrumentation and irrigation techniques.

Single-visit endodontics provide several advantages over multiple visit treatment such as familiarity with internal root canal anatomy, no risk of bacterial leakage between appointments, patient and operator convenience, and lower treatment cost.[3] There have been concerns in performing single-visit endodontics in pulp necrosis cases. However, multiple studies have shown that there is no statistically significant difference in postoperative healing and post treatment flare-ups between vital pulps and necrotic pulps.[21],[22] In fact, certain studies concluded that in asymptomatic necrotic pulps, significantly more flare-ups were present in two-visit cases than single-visit cases.[23],[24],[25] Thus, asymptomatic pulp necrosis cases were chosen for this study.

A diagnosis of pulp necrosis was made for each case based not only on the patient's symptoms but it was also confirmed using electric pulp test. In case of partial vitality of any of the root canals, chances of the patient being completely asymptomatic would be less. Electric pulp test method has been used in similar previously done studies.[18] In the current study, an electric pulp tester was used as it is easy to use and gives a reproducible value.

In a previous study,[17] the reciprocating single-file technique was found to produce a more significant inflammatory response and pain when compared to a rotary nickel–titanium crown down instrumentation technique using Twisted Files. The reciprocation movement is formed by a larger cutting angle and a smaller releasing angle. The file travels apically during releasing angle. Thus, instead of removing debris in the releasing angle, it gets pushed apically. As a result, the WaveOne file acts as a piston to propel debris beyond the apical foramen.

Apart from this, the WaveOne technique is a single-file system of higher taper (usually 0.08 taper, size 25). These instruments are used without any preliminary coronal enlargement. As a result, the entire length of the file contacts the canal wall, increasing the amount of debris formed.

Moreover, cutting ability of a reciprocating file is smaller when compared to continuous rotation, and also debris removal is smaller, thus increasing the frictional stress and torque demand, due to entrapment of debris within the flutes.[26]

The Twisted Files were found to produce intermediate levels of postoperative pain. These files have a triangular cross section and utilize a continuous rotary motion. Twisted File system has been manufactured using the R-phase heat treatment. This makes the files highly flexible with lesser chances of apical transportation. The Twisted File system is used in a crown down sequence. Because of this, with each file used, the debris load was reduced. This led to a decreased amount of debris available to get pushed apically, with most of it being augered out through the orifices.[18]

PTN files produced the least postoperative pain. These files are the convergence of three significant design features, including progressive percentage tapers on a single file, M-wire technology, and the fifth generation of continuous improvement – the offset design.[11]

These files are also used in a crown down sequence, which causes lesser amount of debris to get pushed apically. Apart from this, these files have an offset design that generates a traveling mechanical wave of motion along the active portion of a file. This swaggering effect serves to minimize the engagement between the file and dentin compared to the action of a fixed tapered file with a centered mass of rotation. Reduced engagement limits undesirable taper lock, the screw effect, and the torque on any given file.

A file with an offset design affords more cross-sectional space for enhanced cutting, loading, and augering debris out of a canal compared to a file with a centered mass and axis of rotation. Many instruments break as a result of excessive intrablade debris packed between the cutting flutes over the active portion of a file. Importantly, an offset file design decreases the probability for laterally compacting debris and blocking root canal system anatomy.[11]

Hence, we may conclude that the new PTN system is a unique technique that is able to minimize the risk of pushing debris apically and consequently reduce postoperative pain, a risk which is always present in a reciprocating motion (to a lesser or higher extent), due to the fact that in one sense of rotation, the flutes cut the dentin, whereas in the opposite sense the debris are pushed apically.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Sathorn C, Parashos P, Messer HH. Effectiveness of single-versus multiple-visit endodontic treatment of teeth with apical periodontitis: A systematic review and meta-analysis. Int Endod J 2005;38:347-55.  Back to cited text no. 1
Inamoto K, Kojima K, Nagamatsu K, Hamaguchi A, Nakata K, Nakamura H. A survey of the incidence of single-visit endodontics. J Endod 2002;28:371-4.  Back to cited text no. 2
Ingle JI, Bakland LK, Baumgartner JC. Modern endodontic therapy: Past, present and future. In: Ingle's Endodontics. 6th ed. Hamilton: BC Decker Inc.; 2008. p. 23.  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
Al-Sudani D, Grande NM, Plotino G, Pompa G, Di Carlo S, Testarelli L, et al. Cyclic fatigue of nickel-titanium rotary instruments in a double (S-shaped) simulated curvature. J Endod 2012;38:987-9.  Back to cited text no. 5
Plotino G, Grande NM, Mazza C, Petrovic R, Testarelli L, Gambarini G. Influence of size and taper of artificial canals on the trajectory of NiTi rotary instruments in cyclic fatigue studies. Oral Surg 2010;109:e60-6.  Back to cited text no. 6
Testarelli L, Plotino G, Al-Sudani D, Vincenzi V, Giansiracusa A, Grande NM, et al. Bending properties of a new nickel-titanium alloy with a lower percent by weight of nickel. J Endod 2011;37:1293-5.  Back to cited text no. 7
Kim HC, Kwak SW, Cheung GS, Ko DH, Chung SM, Lee W. Cyclic fatigue and torsional resistance of two new nickel-titanium instruments used in reciprocation motion: Reciproc versus WaveOne. J Endod 2012;38:541-4.  Back to cited text no. 8
Pedullà E, Grande NM, Plotino G, Palermo F, Gambarini G, Rapisarda E. Cyclic fatigue resistance of two reciprocating nickel-titanium instruments after immersion in sodium hypochlorite. Int Endod J 2013;46:155-9.  Back to cited text no. 9
Plotino G, Grande NM, Testarelli L, Gambarini G. Cyclic fatigue of reciproc and WaveOne reciprocating instruments. Int Endod J 2012;45:614-8.  Back to cited text no. 10
Ruddle CJ, Machtou P, West JD. The shaping movement: Fifth-generation technology. Dent Today 2013;32:94, 96-9.  Back to cited text no. 11
Kim HC, Yum J, Hur B, Cheung GS. Cyclic fatigue and fracture characteristics of ground and twisted nickel-titanium rotary files. J Endod 2010;36:147-52.  Back to cited text no. 12
Sharma G, Kakkar P, Vats A. A Comparative SEM investigation of smear layer remaining on dentinal walls by three rotary NiTi files with different cross sectional designs in moderately curved canals. J Clin Diagn Res 2015;9:ZC43-7.  Back to cited text no. 13
Oginni AO, Udoye CI. Endodontic flare-ups: Comparison of incidence between single and multiple visit procedures in patients attending a Nigerian teaching hospital. BMC Oral Health 2004;4:4.  Back to cited text no. 14
Siqueira JF Jr, Rôças IN, Favieri A, Machado AG, Gahyva SM, Oliveira JC, et al. Incidence of postoperative pain after intracanal procedures based on an antimicrobial strategy. J Endod 2002;28:457-60.  Back to cited text no. 15
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. 16
Gambarini G, Sudani DA, 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 2102;10:99-103.  Back to cited text no. 17
Gambarini G, Testarelli L, De Luca M, Milana V, Plotino G, Grande NM, et al. The influence of three different instrumentation techniques on the incidence of postoperative pain after endodontic treatment. Ann Stomatol (Roma) 2013;4:152-5.  Back to cited text no. 18
Plotino G, Grande NM, Cordaro M, Testarelli L, Gambarini G. Measurement of the trajectory of different NiTi rotary instruments in an artificial canal specifically designed for cyclic fatigue tests. Oral Surg 2009;108:e152-6.  Back to cited text no. 19
Plotino G, Grande NM, Cordaro M, Testarelli L, Gambarini G. A review of cyclic fatigue testing of nickel-titanium rotary instruments. J Endod 2009;35:1469-76.  Back to cited text no. 20
Calhoun RL, Landers RR. One-appointment endodontic therapy: A nationwide survey of endodontists. J Endod 1982;8:35-40.  Back to cited text no. 21
Walton R, Fouad A. Endodontic interappointment flare-ups: A prospective study of incidence and related factors. J Endod 1992;18:172-7.  Back to cited text no. 22
Eleazer PD, Eleazer KR. Flare-up rate in pulpally necrotic molars in one-visit versus two-visit endodontic treatment. J Endod 1998;24:614-6.  Back to cited text no. 23
Landers RR, Calhoun RL. One-appointment endodontic therapy: An opinion survey. J Endod. 1980;6:799.  Back to cited text no. 24
Al-Negrish AR, Habahbeh R. Flare up rate related to root canal treatment of asymptomatic pulpally necrotic central incisor teeth in patients attending a military hospital. J Dent 2006;34:635-40.  Back to cited text no. 25
De-Deus G, Barino B, Zamolyi RQ, Souza E, Fonseca A Jr, Fidel S, et al. Suboptimal debridement quality produced by the single-file F2 ProTaper technique in oval-shaped canals. J Endod 2010;36:1897-900.  Back to cited text no. 26


  [Table 1]

This article has been cited by
1 Regulatory Compliance of Health Warnings on Tobacco Packs in Karnataka, India
Somya Mullapudi,Muralidhar M Kulkarni,Veena G Kamath,John Britton,Crawford Moodie,Asha Kamath
Nicotine & Tobacco Research. 2020;
[Pubmed] | [DOI]
2 Assessment of implementation and compliance of (COTPA) Cigarette and Other Tobacco Products Act (2003) in open places of Delhi
Irfan Ali,Basavaraj Patthi,Ashish Singla,Kuldeep Dhama,Mohnish Muchhal,Ananthalekshmy Rajeev,Monika Kumari,Ambar Khan
Journal of Family Medicine and Primary Care. 2020; 9(6): 3094
[Pubmed] | [DOI]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
   Materials and Me...
   Article Tables

 Article Access Statistics
    PDF Downloaded479    
    Comments [Add]    
    Cited by others 2    

Recommend this journal