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Year : 2019  |  Volume : 9  |  Issue : 3  |  Page : 245-249
Shaping ability of 2Shape and WaveOne Gold files using cone-beam computed tomography

1 Department of Conservative Dentistry and Endodontics, Vyas Dental College and Hospital, Jodhpur, Rajasthan, India
2 Department of Dentistry, AIMST University, Semeling, Kedah, Malaysia
3 Department of Oral and Maxillofacial Surgery, Jubilee Mission Medical College Hospital and Research Institute, Thrissur, Kerala, India
4 Department of Pediatric Dentistry, King Khaled Hospital Al Kharj, Riyadh, Kingdom of Saudi Arabia
5 Department of Restorative Dentistry, College of Dentistry, King Khalid University, Abha, Kingdom of Saudi Arabia

Date of Submission25-Nov-2018
Date of Acceptance22-Mar-2019
Date of Web Publication7-Jun-2019

Correspondence Address:
Dr. Shalini Singh
Department of Conservative Dentistry and Endodontics, Vyas Dental College and Hospital, Jodhpur, Rajasthan - 342 005
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jispcd.JISPCD_411_18

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Aim and Objective: The aim of this study is to evaluate the apical transportation, centering ability, and volume of removed dentin of WaveOne Gold (WOG) and 2Shape with the use of cone-beam computed tomography.
Materials and Methods: Freshly extracted mandibular teeth with sample size of thirty were carefully chosen and instrumented using the 2Shape and WOG rotary files. Preoperative and postinstrumentation cone-beam computed tomographic scans were done to accomplish mesial and distal dentin walls' measurements and volume of removed dentin calculations, apical transportation, and centering ratio. Statistical analysis was performed and confirmed by independent t-test. Statistical significance was set at 5%.
Results: When shaping ability of 2Shape and WOG was evaluated, it was reported that there was no statistically significant differences noted among the groups in relation to the total volume of removed dentin, apical transportation, and centering ratio.
Conclusion: It can be concluded that 2Shape and WOG preserved the original canal anatomy well and did not eliminate excess dentin during shaping and cleaning. Rotary nickel–titanium files which work on the principle of rotary movement attained an outcome analogous to that of the rotary files working on reciprocating motion in relation to alteration in angle.

Keywords: Apical transportation, centering ratio, G-wire-reciprocating motion-WaveOne Gold, T-wire-2shape, volume of removed dentin

How to cite this article:
Singh S, Mirdha N, Shilpa P H, Tiwari RV, Abdul MS, Sainudeen S. Shaping ability of 2Shape and WaveOne Gold files using cone-beam computed tomography. J Int Soc Prevent Communit Dent 2019;9:245-9

How to cite this URL:
Singh S, Mirdha N, Shilpa P H, Tiwari RV, Abdul MS, Sainudeen S. Shaping ability of 2Shape and WaveOne Gold files using cone-beam computed tomography. J Int Soc Prevent Communit Dent [serial online] 2019 [cited 2022 Jan 28];9:245-9. Available from: https://www.jispcd.org/text.asp?2019/9/3/245/259806

   Introduction Top

The foremost aim of root canal treatment is to promote the shaping followed by amended cleaning of the root canal, to attribute a conical shape and to preserve the originally existing root canal curvature. Nevertheless, throughout chemomechanical preparation, deviations from the original root canal curvature may occur.[1] These changes could have a pessimistic influence on the superiority of obturation and subsequently on the success of the root canal treatment.[2]

Currently, there are no instruments available which are capable of symmetrically shaping the root canal walls;[3] however, nickel–titanium (NiTi) rotary instruments when compared to stainless steel instruments produce more centralized preparations with a lower transportation.[4]

Recently introduced, 2Shape (2S) NiTi rotary file is made of NiTi-alloy called T-wire. 2Shape has a sequence with two instruments: TS1 (#25, 0.04) and TS2 (#25, 0.06).[5]

Yared proposed a new technique employing reciprocating movements using just one instrument;[6] biomechanical preparation with reciprocating motion has been claimed to lessen the likelihood of unforeseen file fractures. WaveOne Gold (WOG) G-wire technology is available in 4 sizes: small (#20, 0.07), primary (#25, 0.07), medium (#35, 0.06), and large (#45, 0.05).[7]

There is a paucity of literature comparing the shaping ability of 2Shape and WOG. Therefore, this study was planned. Null hypothesis tested as new manufacturing methods and type of rotary motion will not have any effect on their shaping ability of root canals.

   Materials and Methods Top

Sample size was calculated, and thirty freshly extracted mandibular molars were selected, which on radiographic evaluation had canal curvature of 25°–30°, and samples were stored in normal saline till use. Cone-beam computed tomographic scanning was done before instrumentation.

Teeth were accessed with the aid of Endo-Access bur (Dentsply Maillefer) in a high-speed airotor. Through the mesiobuccal canals (MB), 10 K size files (Dentsply Maillefer) were inserted, and the curvature of the canal was evaluated according to Schneider's method. Canals with curvatures of 25°–30° were included for shaping and cleaning. Distal roots were sectioned using low-speed diamond disc with the respective part of the crown from the furcation level and discarded, and only the mesial roots were used for the study. The determination of the working length was established by inserting size 10 K-file to root canal terminus and subtracting 1 mm from this measurement which was then confirmed using electronic apex locator. The teeth were marked from 1 to 30 and divided randomly into two groups of 15 each after randomization of the sample.

Group 1 (2S, n = 15): Instrumented with 2Shape (MicroMega, France) in the sequence TS1>TS2 (6%/#25) as it can be considered as standard control preparation in continuous rotation in pecking motion according to manufacturer's recommendations.

Group 2 (WOG, n = 15): Instrumented with primary file (7%/#25) WOG (Dentsply Maillefer, Switzerland) in reciprocating motion (clockwise – 140° and counterclockwise – 45°).

Root canal shaping

A single operator performed the root canal procedure according to the manufacturer's instructions for each NiTi rotary system. Electric motor (X-Smart plus; Dentsply Maillefer) with a 16:1 reduction handpiece was used for mechanical instrumentation with NiTi rotary files. As a lubricating agent during instrumentation, Glyde (Dentsply Maillefer) was used. A glide path was performed using ProGlider (Dentsply Maillefer; size 16, 0.02 taper) file to the working length. Apical preparation was completed with a size 25 file using the file order specified by the manufacturer. During instrumentation, irrigation of the canals was done with 2 mL 5% NaOCl. After instrumentation, 1 mL of 17% ethylenediaminetetraacetic acid was applied for 3 min followed by final irrigation with 3 mL of NaOCl. Each instrument was used to prepare three canals and then discarded.

Cone-beam computed tomography analysis

Custom-made specimen holders were used for placement of sectioned tooth in which each root could be positioned in the same place before and after instrumentation. Pre- and post-instrumentation measurements of MB canals were achieved. The volume of removed dentine was measured in mm3 for each root canal by subtracting the uninstrumented canal volume from the instrumented canal volume [Figure 1]. Canal transportation and centering ratio were calculated at three cross-section levels, i.e., 3, 5, and 7 mm from the apical end of the root using the following equation:
Figure 1: Pre- and post-instrumentation cone-beam computed tomography images

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Degree of canal transportation: Mesiodistally = (m1 − m2) − (d1 − d2).

Canal centering ratio = (m1 − m2)/(d1 − d2) or (d1 − d2)/(m1 − m2).

Statistical analysis

A statistical analysis (SPSS 15.0; SPSS Inc., Chicago, IL, USA) of the data was performed, each set of measurements were analyzed using the Kolmogorov–Smirnov test. Statistical significance level was set at P < 0.05.

   Results Top

Volume of removed dentine

[Table 1] shows the mean ± standard deviation of volume of removed dentine (mm) for tested groups and statistical analysis. There is no significant difference between the two tested groups (P > 0.05).
Table 1: Mean and standard deviation values for volume of removed dentin detected at 3 different levels (mm)

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Canal transportation

There is no statistically significant difference reported as shown in [Table 2] for degree of canal transportation mesiodistally for tested groups (P > 0.05). Graphical representation of canal transportation is shown in [Graph 1].
Table 2: Mean and standard deviation values for the amount of canal transportation irrespective of the direction at 3 measurement levels (mm)

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Centering ratio

No statistically significant difference between the two tested groups is noticed (P > 0.05), as shown in [Table 3]. Graphical representation of canal transportation is shown in [Graph 2].
Table 3: Centering ratio means and standard deviations detected at 3 different levels (mm)

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[Table 2] shows the mean and standard deviation values of the canal transportation at the three studied levels (3, 5, and 7 mm) for each tested group. Both the tested groups showed similar results when compared.

[Table 3] shows the mean and standard deviation values of the centering ratio at the three studied levels (3, 5, and 7 mm) for each tested group. Both the tested groups showed similar results when compared.

   Discussion Top

The purpose of this study is to compare the shaping ability of two recently introduced NiTi rotary instruments recommended for the preparation of curved root canals, one of which is activated by reciprocating movement and one by continuous rotary movement. The following parameters were evaluated: volume of removed dentin, apical transportation, and centering ratio.

Crowns corresponding to the mesial roots were retained to mimic the clinical conditions where the tension is produced during canal instrumentation by file, due to the interference of cervical dentine projections.[8]

For assessment of shaping ability, cone-beam computed tomography imaging technique was used as it provides a specific, reproducible, and three-dimensional assessment of dentine thickness and root canal volume alteration before and after preparation without damaging the specimens.[9]

The angle of curvature at 25°–30° was preferred as it is considered as moderate curvature according to American Association of Endodontists Endodontic Case Difficulty Assessment to obtain results that cover a large scale of cases.[10]

Curvatures with high susceptibility to iatrogenic mishaps usually exist at these three levels: 3, 5, and 7 mm, which represent the apical, middle, and coronal thirds of the root canals, respectively; hence, they were chosen for evaluation in the study.[11]

In this study, there was no statistically significant difference reported between 2Shape and WOG systems when the volume of removed dentin was evaluated, as shown in [Graph 1] (P > 0.05).

There was no statistically significant difference noted between 2Shape and WOG systems (P > 0.05) while assessing the canal transportation [Graph 2] and centering ratio [Graph 3] at all the levels 3 mm, 5 mm, 7 mm. The probable reason could be the tip design, metallurgy, file cross-section, and principle working motion of each file system.

2Shape (2S) NiTi rotary file works on rotating motion and is made of NiTi-alloy called T-wire which is a method which allows for an increased resistance to cyclic fatigue (+40%) and a better negotiation of curvatures. The two instruments – TS1 (0.25/0.04) and TS2 (0.25/0.06) return to their original shape after each use. A latest generation of cross-section with tripe helix: two primary cutting edges and 1 secondary cutting-edge aids in the perfect compromise between cutting efficiency and debris removal.[5]

WOG works on the principle of reciprocating motion and is claimed to be able to completely shape and clean root canals with only one single use instrument. These files are made of a special NiTi-alloy called G-Wire which is created by an innovative thermal treatment process. The benefits of this G-Wire NiTi are increased flexibility of the instruments and improved resistance to cyclic fatigue. Reverse helix, semi-active and modified guiding tip, and offset parallelogram-shaped cross-section limit the engagement zone. Reciprocating movement minimizes torsional and flexural stresses, increases the centering ability of canal, and reduces the taper lock of the instrument within the canal.[12],[13],[14],[15]

An in-vitro study on shaping ability of Reciproc, WOG, and HyFlex EDM Single-file Systems in Simulated S-shaped Canals was conducted by Ozyurek et al. in the year 2017; it was concluded that all the NiTi files produced various levels of removal of resin.[12] However, the lower level of resin removal was reported with the use of WOG and HEDM NiTi files as compared to the RPC NiTi files. The results for WOG were in accordance with our study stating less volume of removed dentin.[16]

Similarly, the results of the study done by Abdullah et al. in 2018 comparing the shaping ability of ProTaper Gold and WOG system in simulated S- and L-shaped canals revealed that there was a highly significant difference noted in preparation, and it was concluded that WOG showed better shaping ability with less canal aberrations and faster canal preparation as compared to ProTaper Gold.[17] Hence, it is supporting the results of the current study that WOG respects the canal anatomy better when used for chemomechanical preparation. Simone Staffoli et al. in 2018 conducted the study to compare the centering ability of ProTaper Next and 2Shape file system on simulated teeth with severe curvature; it was reported that there was no significant difference in centering ability of ProTaper Next and 2Shape. Both the file systems showed some degree of canal transportation, especially in the apical third.[18],[19]

The 2Shape and WOG NiTi rotary systems revealed comparable volume of removed dentine, canal transportation, and centering ratio. There is a paucity of literature on shaping ability of 2Shape system; hence, the file system was selected for the study. Further investigations to the metallurgy and mechanical properties of these recent systems are required to gain insight on how the proprietary advanced metallurgy processing of these affects its properties. In addition, evaluations of the clinical performance of these systems in vivo are needed to provide reliable recommendations for endodontists.

   Conclusion Top

Within the limitations of this in-vitro study, both 2Shape and WGO rotary systems performed similarly with regard to volume of removed dentin, canal transportation, and centering ratio and were able to maintain the original canal curvature in mesial canals of mandibular molars.

Financial Support and Sponsorship


Conflicts of Interest

There are no conflicts of interest.

   References Top

Saber SE, Nagy MM, Schäfer E. Comparative evaluation of the shaping ability of WaveOne, Reciproc and OneShape single-file systems in severely curved root canals of extracted teeth. Int Endod J 2015;48:109-14.  Back to cited text no. 1
Wu MK, Fan B, Wesselink PR. Leakage along apical root fillings in curved root canals. Part I: Effects of apical transportation on seal of root fillings. J Endod 2000;26:210-6.  Back to cited text no. 2
Foschi F, Nucci C, Montebugnoli L, Marchionni S, Breschi L, Malagnino VA, et al. SEM evaluation of canal wall dentine following use of Mtwo and ProTaper NiTi rotary instruments. Int Endod J 2004;37:832-9.  Back to cited text no. 3
Glossen CR, Haller RH, Dove SB, del Rio CE. A comparison of root canal preparations using Ni-Ti hand, Ni-Ti Engine-driven, and K-flex endodontic instruments. J Endod 1995;21:146-51.  Back to cited text no. 4
Micro Mega, France 2Shape. Available from: http://www.micro-mega.com/shaping/2shape?lang=en. [Last accessed on 2017 Sep 17].  Back to cited text no. 5
Yared G. Canal preparation using only one Ni-Ti rotary instrument: Preliminary observations. Int Endod J 2008;41:339-44.  Back to cited text no. 6
Dentsply Tulsa Dental Specialties. WaveOne Gold. Available from: https://www. Dentsply.com/content/dam/dentsply/pim/manufacturer/Endodontics/Obturation/Gutta_Percha_Points/WaveOne_Gold_Gutta_ Percha_Points/W1G_Brochure_EN.pdf. [Last accessed on 2016 Oct 14].  Back to cited text no. 7
Hashem AA, Ghoneim AG, Lutfy RA, Foda MY, Omar GA. Geometric analysis of root canals prepared by four rotary NiTi shaping systems. J Endod 2012;38:996-1000.  Back to cited text no. 8
Hartmann MS, Barletta FB, Camargo Fontanella VR, Vanni JR. Canal transportation after root canal instrumentation: A comparative study with computed tomography. J Endod 2007;33:962-5.  Back to cited text no. 9
Schneider SW. A comparison of canal preparations in straight and curved root canals. Oral Surg Oral Med Oral Pathol 1971;32:271-5.  Back to cited text no. 10
Michetti J, Maret D, Mallet JP, Diemer F. Validation of cone beam computed tomography as a tool to explore root canal anatomy. J Endod 2010;36:1187-90.  Back to cited text no. 11
Özyürek T, Yılmaz K, Uslu G. Shaping ability of Reciproc, WaveOne GOLD, and HyFlex EDM single-file systems in simulated S-shaped canals. J Endod 2017;43:805-9.  Back to cited text no. 12
Takeshi U, Michiko H, Kaori S, Ryoichiro W, Ikuya S, Noriko M, et al. The study of shaping ability using WaveOne Gold. Japn J Conserv Dent 2016;59:111-8.  Back to cited text no. 13
Guillén RE, Nabeshima CK, Caballero-Flores H, Cayón MR, Mercadé M, Cai S, et al. Evaluation of the WaveOne Gold and one shape new generation in reducing Enterococcus faecalis from root canal. Braz Dent J 2018;29:249-53.  Back to cited text no. 14
Webber J. Shaping canals with confidence: WaveOne GOLD single-file reciprocating system. Int Dent Afr Ed 2016;6:6-17.  Back to cited text no. 15
Surakanti JR, Punna R, Vanapatla A, Vemisetty H. Comparative evaluation of cleaning ability of Reciproc and WaveOne Gold reciprocating file systems – A scanning electron microscopic study. Indian J Dent Sci 2018;10:98-101.  Back to cited text no. 16
  [Full text]  
Abdullah A, Mohammad A, Thomas S, Abdul M. Shaping ability of ProTaper Gold and WaveOne Gold nickel-titanium rotary file in different canal configurations. Saudi Endod J 2018;8:202-7.  Back to cited text no. 17
Staffoli S, Ozyurek T, Hadad A, Lvovsky A. Comparison of shaping ability of ProTaper next and 2Shape nickel-titanium files in simulated severe curved canals. G Ital Endod 2018;32:52-6.  Back to cited text no. 18
Rubio J, Zarzosa JI, Pallarés A. Comparison of shaping ability of 10 rotary and reciprocating systems: An in vitro study with AutoCad. Acta Stomatol Croat 2017;51:207-16.  Back to cited text no. 19


  [Figure 1]

  [Table 1], [Table 2], [Table 3]

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