Journal of Conservative Dentistry
Home About us Editorial Board Instructions Submission Subscribe Advertise Contact e-Alerts Login 
Users Online: 273
Print this page  Email this page Bookmark this page Small font sizeDefault font sizeIncrease font size
 


 
Table of Contents   
ORIGINAL RESEARCH ARTICLE  
Year : 2017  |  Volume : 20  |  Issue : 6  |  Page : 459-462
Incidence of dentinal defects during root canal preparation with hand files using different irrigants: An in vitro study


Department of Conservative Dentistry and Endodontics, Dr. HSJ Institute of Dental Sciences and Hospital, Panjab University, Chandigarh, India

Click here for correspondence address and email

Date of Submission25-Jul-2017
Date of Decision17-Oct-2017
Date of Acceptance21-Nov-2017
Date of Web Publication15-Jan-2018
 

   Abstract 


Introduction: The purpose of this in vitro study was to compare the incidence of dentinal defects during root canal preparation with hand files using different irrigants.
Materials and Methods: A total of 120 extracted mandibular incisors were randomly divided into onecontrol group and five experimental groups (n = 20) depending on the irrigant used. Biomechanical preparation was not done in control group. Teeth in experimental groups were prepared with hand K-files to a master apical file #35 with 1-mm increments step-back up to #50. In Group 2, saline was used as an irrigant. In Groups 3, 4, 5, and 6, 3% sodium hypochlorite (NaOCL), SmearClear, 17% ethylenediaminetetraacetic acid (EDTA), and 2% chlorhexidine (CHX), respectively, were used as an irrigant. Specimens were sectioned perpendicular to the long axis at 3, 6, and 9 mm from the apex. Sections were observed under a digital stereomicroscope at 30× magnification. Two-tailed t-test was used for statistical analysis.
Results: There was a statistically significant difference between the six groups. Group 5 (17% EDTA) had the highest number of dentinal defects, followed by Group 3 (3% NaOCl), Group 4 (SmearClear), and Group 6 (2% CHX).
Conclusions: 17% EDTA causes more dentinal defects as compared to 3% NaOCl, SmearClear, 2% CHX, and saline.

Keywords: 17% ethylenediaminetetraacetic acid; chlorhexidine; irrigant; SmearClear, sodium hypochlorite

How to cite this article:
Singla R, Jhamb S, Kaur A, Vashisht R. Incidence of dentinal defects during root canal preparation with hand files using different irrigants: An in vitro study. J Conserv Dent 2017;20:459-62

How to cite this URL:
Singla R, Jhamb S, Kaur A, Vashisht R. Incidence of dentinal defects during root canal preparation with hand files using different irrigants: An in vitro study. J Conserv Dent [serial online] 2017 [cited 2020 Sep 20];20:459-62. Available from: http://www.jcd.org.in/text.asp?2017/20/6/459/223190



   Introduction Top


The primary aim of the chemomechanical preparation is to completely remove the microorganisms, pulp tissue, and debris and to enlarge the canal diameter to receive an obturating material.[1] Perforation, canal transportation, ledge or zip formation, and fracture of files are some of the complications that may occur during the root canal preparation.[2],[3] Some recent studies have shown that canal instrumentation also has the potential to cause dentinal defects.[4],[5] These defects can propagate into vertical root fracture if the tooth is subjected to repeated occlusal forces.[6],[7]

The use of irrigants during instrumentation to clean all aspects of the root canal system is central to successful endodontic treatment.[8] Irrigation is complementary to instrumentation in facilitating the removal of pulp tissue and/or microorganisms.[9] A large number of substances have been used as root canal irrigants.

Sodium hypochlorite (NaOCl) with a concentration ranging between 1% and 5.25% is the most widely used irrigant in root canal treatment because of its antimicrobial activity and the capability to dissolve organic tissues.[10]

Chelating agents decalcify the dentin by combining with the calcium ions of the tooth.[11] Ethylenediaminetetraacetic acid (EDTA) is generally accepted as the most effective chelating solution in endodontic therapy. SmearClear (SybronEndo, Orange, CA, USA) is a 17% EDTA solution including cationic and an inorganic surfactant.

2% chlorhexidine (CHX) has been used in endodontics as an irrigating substance due to its biocompatibility,[12] substantivity,[13] lubricating property, and rheological actions.

The purpose of the following in vitro study was to compare the incidence of dentinal defects during root canal preparation with hand files using different irrigants.


   Materials and Methods Top


A total of 120 extracted mandibular incisors with single canal were used in this study. Buccolingual and mesiodistal radiographs were taken to verify the presence of the single canal. Teeth with external cracks or defects, deep caries, with previous restorations, immature apices, and teeth with more than one canal were excluded from this study. The root surfaces were observed under ×30 in a digital stereomicroscope to exclude cracks. All the teeth were decoronated using a diamond disc in a micromotor under copious water cooling, leaving a root length of approximately 12 ± 1 mm. A silicon impression material was used for coating the root surface to simulate periodontal ligament (PDL) space. The roots were divided into six groups (n = 20) depending on the irrigant used.

  • Group 1: Served as a control group, no biomechanical preparation was done
  • Group 2: Biomechanical preparation was done using saline as an irrigant
  • Group 3: 3% NaOCl was used as an irrigant
  • Group 4: SmearClear was used as an irrigant
  • Group 5: 17% EDTA was used as an irrigant
  • Group 6: 2% CHX was used as an irrigant.


Shaping and cleaning

The canals were prepared with K-file (Dentsply-Maillefer Ballaigues, Switzerland) to a master apical file #35 with 1-mm increments step-back up to #50. Canals were irrigated with respective irrigant after each instrument change. A volume of 16 ml irrigant was used in each canal.

Sectioning and observation

Specimens were sectioned perpendicular to the long axis at 3, 6, and 9 mm from the apex using Isomet 1000 Precision Saw (Buehler, an ITW Company, IL, USA) under water cooling. Sections were observed under a digital stereomicroscope (Carl Zeiss, Oberkochen, Germany) at ×30 [Figure 1]. Images were blindly checked by two operators for the presence of defects.
Figure 1: Sections observed under a digital stereomicroscope

Click here to view


Definitions of the dentinal defects

Dentinal defects were classified according to Wilcox et al.[6] “No defect” was defined as root dentin devoid of any cracks. “Defect” was defined as fracture lines (Type I defect) and craze lines or partial cracks (Type II defect) [Figure 2].
Figure 2: Classification of dentinal defects: (a) no defect, (b) fracture line (Type I), (c) craze line or partial crack (Type II)

Click here to view


Statistical analysis

Results were expressed as the number and percentage of roots showing dentinal defects in each group. Two-tailed t-test was used for statistical analysis of difference between and among the experimental groups.


   Results Top


No cracks were observed in the control group. Dentinal defects were found in all experimental groups. The results are shown in [Table 1] and [Graph 1]. There was a statistically significant difference between the six groups. Group 5 (17% EDTA) had the highest number of dentinal defects, followed by Group 3 (3% NaOCl), Group 4 (SmearClear), and Group 6 (2% CHX). Groups 3, 4, 5, and 6 were statistically different from Group 1 [Table 2].
Table 1: Number and percentage of root sections presenting different types of dentinal defects in experimental groups

Click here to view
Table 2: Statistical analysis between groups using two-tailed t-test

Click here to view




   Discussion Top


In the present study, mandibular incisors of nearly similar root size were selected to minimize anatomical variations. All teeth were inspected by stereomicroscope and radiograph for the exclusion of teeth with crack or fracture. The sectioning procedure had no influence on crack formation because the control teeth did not show any defects. This is in agreement with other studies that used a similar method.[5],[14] The root surfaces were coated with a layer of silicone impression material before placing within the acrylic blocks to simulate PDLs and distribute stresses during root canal preparation.[15]

In this study, 3% NaOCl, 17% EDTA, SmearClear, and CHX were used because these are the most commonly used endodontic irrigants.

No significant difference was found between Group 1 (control) and Group 2 (saline). This result is consistent with the previous study of Adl et al., which showed fewest cracks with saline.[16]

In the present study, the highest number of dentinal defects was observed in Group 5 (17% EDTA). This means in comparison with other groups, chelating action of 17% EDTA solution induces an adverse softening potential on the calcified components of dentin and reduces the microhardness of dentin.[17]

The present study is in accordance with Saleh and Ettma, who evaluated the effect of NaOCl and EDTA on the microhardness of root canal dentin and reported that both solutions decreased the microhardness of root dentin, but EDTA irrigation induced more reduction.[18]

Group 3 (3% NaOCl) showed significantly more defects when compared to the control group. This finding is compatible with the result of previous studies showing that NaOCl reduces microhardness, elastic modulus, and flexural strength of dentin.[19]

SmearClear (SybronEndo) contains 17% EDTA, cetrimide, and surfactant. Addition of a wetting agent reduces the surface tension and the effectiveness of calcium removal as compared to EDTA.[20]

Significant difference was found between Group 1 (control) and Group 6 (2% CHX). This is in accordance to the study of Oliveira et al., which showed 2% CHX significantly decreased the microhardness of dentin.[21]

Studies have evaluated and compared the potential effects of different preparation systems on dentinal defects; however, a literature search did not reveal any previous studies on the effects of different irrigation solutions on dentinal defect formation during root canal preparation. This study showed that endodontic irrigants are associated with risk of creating dentinal defects.

In our study, few internal craze lines were observed, and most of the defects were external cracks. These results are consistent with the results of a study by Shemesh et al.[4] and Milani et al.[22] This may be due to the stress generated by instrumentation within the canal, which is transmitted to the outer surface of the tooth where it overcomes the bonds holding the dentin together.[23]


   Conclusions Top


17% EDTA causes more dentinal defects as compared to 3% NaOCl, SmearClear, and 2% CHX.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Schilder H. Cleaning and shaping the root canal. Dent Clin North Am 1974;18:269-96.  Back to cited text no. 1
[PUBMED]    
2.
Tsesis I, Rosenberg E, Faivishevsky V, Kfir A, Katz M, Rosen E, et al. Prevalence and associated periodontal status of teeth with root perforation: A retrospective study of 2,002 patients' medical records. J Endod 2010;36:797-800.  Back to cited text no. 2
    
3.
Aydin B, Köse T, Calişkan MK. Effectiveness of HERO 642 versus Hedström files for removing gutta-percha fillings in curved root canals: An ex vivo study. Int Endod J 2009;42:1050-6.  Back to cited text no. 3
    
4.
Shemesh H, Bier CA, Wu MK, Tanomaru-Filho M, Wesselink PR. The effects of canal preparation and filling on the incidence of dentinal defects. Int Endod J 2009;42:208-13.  Back to cited text no. 4
[PUBMED]    
5.
Bier CA, Shemesh H, Tanomaru-Filho M, Wesselink PR, Wu MK. The ability of different nickel-titanium rotary instruments to induce dentinal damage during canal preparation. J Endod 2009;35:236-8.  Back to cited text no. 5
[PUBMED]    
6.
Wilcox LR, Roskelley C, Sutton T. The relationship of root canal enlargement to finger-spreader induced vertical root fracture. J Endod 1997;23:533-4.  Back to cited text no. 6
[PUBMED]    
7.
Shemesh H, van Soest G, Wu MK, Wesselink PR. Diagnosis of vertical root fractures with optical coherence tomography. J Endod 2008;34:739-42.  Back to cited text no. 7
[PUBMED]    
8.
Shen Y, Stojicic S, Qian W, Olsen I, Haapasalo M. The synergistic antimicrobial effect by mechanical agitation and two chlorhexidine preparations on biofilm bacteria. J Endod 2010;36:100-4.  Back to cited text no. 8
[PUBMED]    
9.
Haapasalo M, Endal U, Zandi H, Coil JM. Eradication of endodontic infection by instrumentation and irrigation solutions. Endod Topics 2005;10:77-102.  Back to cited text no. 9
    
10.
Sena NT, Gomes BP, Vianna ME, Berber VB, Zaia AA, Ferraz CC, et al. In vitro antimicrobial activity of sodium hypochlorite and chlorhexidine against selected single-species biofilms. Int Endod J 2006;39:878-85.  Back to cited text no. 10
[PUBMED]    
11.
Scelza MF, Pierro V, Scelza P, Pereira M. Effect of three different time periods of irrigation with EDTA-T, EDTA, and citric acid on smear layer removal. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:499-503.  Back to cited text no. 11
[PUBMED]    
12.
Tanomaru Filho M, Leonardo MR, Silva LA, Aníbal FF, Faccioli LH. Inflammatory response to different endodontic irrigating solutions. Int Endod J 2002;35:735-9.  Back to cited text no. 12
    
13.
Rosenthal S, Spångberg L, Safavi K. Chlorhexidine substantivity in root canal dentin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:488-92.  Back to cited text no. 13
    
14.
Adorno CG, Yoshioka T, Suda H. The effect of working length and root canal preparation technique on crack development in the apical root canal wall. Int Endod J 2010;43:321-7.  Back to cited text no. 14
[PUBMED]    
15.
Rosentritt M, Fürer C, Behr M, Lang R, Handel G. Comparison of in vitro fracture strength of metallic and tooth-coloured posts and cores. J Oral Rehabil 2000;27:595-601.  Back to cited text no. 15
    
16.
Adl A, Sedigh-Shams M, Majd M. The effect of using RC prep during root canal preparation on the incidence of dentinal defects. J Endod 2015;41:376-9.  Back to cited text no. 16
[PUBMED]    
17.
Sayin TC, Serper A, Cehreli ZC, Kalayci S. Calcium loss from root canal dentin following EDTA, EGTA, EDTAC, and tetracycline-HCl treatment with or without subsequent NaOCl irrigation. J Endod 2007;33:581-4.  Back to cited text no. 17
[PUBMED]    
18.
Saleh AA, Ettman WM. Effect of endodontic irrigation solutions on microhardness of root canal dentine. J Dent 1999;27:43-6.  Back to cited text no. 18
[PUBMED]    
19.
Sim TP, Knowles JC, Ng YL, Shelton J, Gulabivala K. Effect of sodium hypochlorite on mechanical properties of dentine and tooth surface strain. Int Endod J 2001;34:120-32.  Back to cited text no. 19
[PUBMED]    
20.
Zehnder M, Schicht O, Sener B, Schmidlin P. Reducing surface tension in endodontic chelator solutions has no effect on their ability to remove calcium from instrumented root canals. J Endod 2005;31:590-2.  Back to cited text no. 20
[PUBMED]    
21.
Oliveira LD, Carvalho CA, Nunes W, Valera MC, Camargo CH, Jorge AO, et al. Effects of chlorhexidine and sodium hypochlorite on the microhardness of root canal dentin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:e125-8.  Back to cited text no. 21
    
22.
Milani AS, Froughreyhani M, Rahimi S, Jafarabadi MA, Paksefat S. The effect of root canal preparation on the development of dentin cracks. Iran Endod J 2012;7:177-82.  Back to cited text no. 22
[PUBMED]    
23.
Alapati SB, Brantley WA, Iijima M, Clark WA, Kovarik L, Buie C, et al. Metallurgical characterization of a new nickel-titanium wire for rotary endodontic instruments. J Endod 2009;35:1589-93.  Back to cited text no. 23
[PUBMED]    

Top
Correspondence Address:
Ruchi Singla
Department of Conservative Dentistry and Endodontics, Dr. HSJ Institute of Dental Sciences and Hospital, Panjab University, Chandigarh
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/JCD.JCD_215_17

Rights and Permissions


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2]



 

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


    Abstract
   Introduction
    Materials and Me...
   Results
   Discussion
   Conclusions
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed1011    
    Printed7    
    Emailed0    
    PDF Downloaded193    
    Comments [Add]    

Recommend this journal