|Year : 2020 | Volume
| Issue : 4 | Page : 209-215
Comparative evaluation and efficacy of ethylenediaminetetracetic acid, carbonated water, and chloroquick as final irrigant in smear layer removal using scanning electron microscope
Vipul Srivastava, Nazia Ali, Ayush Razdan Singh, Raju Chauhan
Department of Conservative Dentistry and Endodontics, Saraswati Dental College, Lucknow, Uttar Pradesh, India
|Date of Submission||18-May-2020|
|Date of Decision||26-Jun-2020|
|Date of Acceptance||03-Nov-2020|
|Date of Web Publication||18-Jan-2021|
Dr. Raju Chauhan
Department of Conservative Dentistry and Endodontics, Saraswati Dental College, Tiwariganj, Faizabad Road, Lucknow, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
Aim: The purpose of this study was to evaluate and compare the efficacy of EDTA, carbonated water, and chloroquick in smear layer removal at apical, middle, and coronal third of the root canal.
Materials and Methods: Eighty freshly extracted human mandibular premolars were used for the study The teeth were decoronated to obtain standardized working length of 14 mm. All samples were instrumented with ProTaper gold till apical size #F3 with 3% NaOCl irrigation between each file. The samples were randomly divided into four groups (n = 20) on the basis of final irrigant used: Group I: 17% ethylenediaminetetracetic acid (EDTA), Group II: carbonated water, Group III: chloroquick solution, and Group IV: normal saline (negative control). The samples were then split into longitudinal sections and observed under scanning electron microscope (SEM) at apical, middle, and coronal levels for the amount of smear layer present.
Statistical Analysis: Data were analyzed statistically using Kruskal–Wallis analysis of variance followed by the Mann–Whitney U-test and Chi-square test. The level of significance was set at 0.05.
Results: The present study showed that all the three experimental irrigants removed the smear layer equally at the middle and coronal third. At the apical third, Group III (Chloroquick solution) showed the least smear layer score (2.20 ± 0.41) followed by Group I (17% EDTA) (2.35 ± 0.49) and then Group II (Carbonated water) (2.45 ± 0.51). The P value was found to be < 0.001.
Conclusion: Chloroquick is more effective in smear layer removal in apical third followed by 17% EDTA and then carbonated water when used as final irrigant. No statistically significant result was found in smear layer removal among the three groups at coronal and middle third of the root canal.
Keywords: Carbonated water, chloroquick, ethylenediaminetetracetic acid, scanning electron microscope, smear layer
|How to cite this article:|
Srivastava V, Ali N, Singh AR, Chauhan R. Comparative evaluation and efficacy of ethylenediaminetetracetic acid, carbonated water, and chloroquick as final irrigant in smear layer removal using scanning electron microscope. Endodontology 2020;32:209-15
|How to cite this URL:|
Srivastava V, Ali N, Singh AR, Chauhan R. Comparative evaluation and efficacy of ethylenediaminetetracetic acid, carbonated water, and chloroquick as final irrigant in smear layer removal using scanning electron microscope. Endodontology [serial online] 2020 [cited 2021 Mar 2];32:209-15. Available from: https://www.endodontologyonweb.org/text.asp?2020/32/4/209/307317
| Introduction|| |
Elimination of micro-organisms from the root canal system and prevention of reinfection is the main aim of the root canal treatment. The current root canal instrumentation methods produce a granular amorphous layer covering the dentin, referred to as smear layer. The smear layer consists of both organic and inorganic substances covering the root canal walls and openings of the dentinal tubules. The smear layer can act as barrier between obturating materials and the canal wall, and thus, interfere with the formation of an appropriate seal. Hence, thorough debridement of the root canal system for removing smear layer is crucial for the long-term success of root canal treatment.
Ethylenediaminetetraacetic acid (EDTA) acts on the inorganic material by reacting with calcium ions in dentine, resulting in calcium chelation, promoting decalcification of dentin at depths of 20–30 μm within 5 min. Wu et al. showed that the smear layer removal ability of 17% EDTA was significantly better than 20% of citric acid and MTAD (Biopure™ mixture of tetracycline isomer, acid and detergent).
Chloroquick is a one-step irrigation solution which acts by chelating and emulsifying action. Chloroquick contains 18% etidronate or etidronic acid, i.e., 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) and 5% NaOCl, premixed with surfactant tween 80 for a complete root canal irrigation solution. Etidronic acid is a biocompatible chelator that can be used in combination with sodium hypochlorite and has good calcium chelating action. The highlight of such combination is that the NaOCl does not surrender its biological, antibacterial, and tissue dissolving properties, whereas the reduction and elimination of the inorganic elements are done with the help of etidronic acid.,, Karale et al. reported in their study that HEBP showed effective antimicrobial effect without interfering with antimicrobial properties of sodium hypochlorite or chlorhexidine.
Carbonated water (H2CO3) has pH 3 to 4, capable of removing smear layer and opens dentinal tubules. When carbon dioxide is exposed to atmosphere, bubble formation occurs which helps in smear layer removal.
Very few studies are conducted till date on chloroquick and carbonated water using as an irrigant. The present study evaluates and compares the efficiency of 17% EDTA, carbonated water, and chloroquick solution in their ability to remove smear layer at coronal, middle, and apical third of root canal when used as final irrigant. The null hypothesis for the study was that, all the four irrigants are equally effective in smear layer removal.
| Materials and Methods|| |
Selection of samples
Eighty freshly extracted single rooted human mandibular premolars were collected. Carious or fractured teeth, teeth with open apices, with resorption, craze line, and calcified canals were excluded. The teeth were digitally radiographed to ensure that they have a single canal and orifice. They were decoronated by diamond disk to standardize the root length of 14 mm for all samples.
Preparation of root canals and sample distribution
Endodontic access was obtained and patency established with size 10K-file (DENTSPLY Maillefer, Ballaigues, Switzerland). After achieving working length, 1 mm short from the apex, apical preparation was done till #15 K File. All teeth were then prepared using ProTaper gold (Dentsply Maillefer, Ballaigues, Switzerland), till master apical size #F3, according to manufacturer's specifications. Irrigation was done by 1 ml of 3% sodium hypochlorite solution (Parcan, Septodont Health care, India) using side vented needle (Top Endo, NMD India) between each instrument change. The irrigation needle was kept 1 mm short from the working length for effective irrigation of apical third area.
All samples were then randomly divided into four groups depending on the type of final irrigant used with 20 samples in each group; n = 20.
- Group I: (17% EDTA) – Final irrigation was done with 5 ml of 17% EDTA for 3 min followed by 3 ml of distilled water (Smear Clear, Sybron Endo, Orange, CA, USA)
- Group II: (carbonated water) – Final irrigation was done with 5 ml of carbonated water for 3 min followed by 3 ml of distilled water (Kinley Soda, Coca-Cola, India)
- Group III: (Chloroquick solution) – Final irrigation was done with 5 ml of chloroquick solution for 3 min followed by 3 ml of distilled water (ZoDenta, Innovations Endo, India).
- Group IV: (normal saline) – Final irrigation was done with 5 ml of normal saline for 3 min followed by 3 ml of distilled water (Lxir Medilabs Pvt. Ltd., India).
Scanning electron microscopy evaluation and scoring
After irrigation, all root canals were dried with absorbent paper points. Longitudinal grooves were prepared on buccal and lingual surfaces of each root using a diamond disc. The roots were then split into two halves using a chisel and mallet to be observed under scanning electron microscope (SEM). Coded samples were mounted on metallic stubs, gold sputtered and viewed under a SEM (JSM 5600LV, Jeon Inc., Peabody, MA, USA) in ×3000 at coronal, middle, and apical third.
The photomicrographs were observed by another experienced operator who was not informed about the experimental protocol. The images were scored according to the criteria given by Torabinejad et al. which measure the presence, quantity, and distribution of the smear layer.
- Score 1 – no smear layer. (no smear layer on the surface of the root canal: all tubules were clean and open)
- Score 2 – moderate smear layer. (no smear layer on the surface of the root canal, but tubules contained debris)
- Score 3 – heavy smear layer. (smear layer covered the root canal surface and the tubules).
The data were entered into Epi Info version 3.5.1 (CDC, Atlanta, Georgia, U.S.A) and analyzed using the Statistical Package for the Social Sciences (SPSS) software version 21 (IBM SPSS Statistics for Windows, version 21.0. IBM Corp., Armonk, NY, USA). Kruskal–Wallis test was used for intragroup comparisons and Mann–Whitney U-test was used for intergroup comparisons followed by the Chi-square test [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10]. Significance for all statistical tests was predetermined at P < 0.05.
| Results|| |
No statistical difference was found in all groups in smear layer score at coronal and middle third of the root canal, but there was statistical difference when the scores were compared at apical third. At the apical third, Group III (Chloroquick solution) showed the least smear layer score (2.20 ± 0.41) followed by Group I (17% EDTA) (2.35 ± 0.49), then Group II (Carbonated water) (2.45 ± 0.51) and Group IV (normal saline) (3.00) [Table 1].
All tested irrigants removed smear layer effectively from coronal and middle third, and there was no significant difference [Figure 1] and [Figure 2]. At the apical third, there was significant difference between the groups. Group III (Chloroquick solution) has no smear layer on the surface of the root canal; all tubules were clean and open [Figure 3]. Group I (EDTA) has no smear layer on the surface of the root canal, but few tubules contained debris [Figure 3]. Group II (carbonated water) has no smear layer on the surface of the root canal, but all tubules contained debris and Group IV (normal saline) has smear layer covering the root canal surface and the tubules [Figure 3]. This can also be seen in the graphical representation of scores obtained for all groups [Graph 1].
|Figure 1: Scanning electron microscope images of all groups at coronal third of root canal (×3000); (a) sample of Group I, (b) sample of Group II, (c) sample of Group III; the dentinal tubules are cleaner in this group (d) sample of Group IV|
Click here to view
|Figure 2: Scanning electron microscope images of all groups at middle third of root canal (×3000); (a) sample of Group I, (b) sample of Group II, (c) sample of Group III; smear layer is less here compared to other groups (d) sample of Group IV|
Click here to view
|Figure 3: Scanning electron microscope images of all groups at apical third of root canal (×3000); (a) sample of Group I, (b) sample of Group II, (c) sample of Group III; this group appears to have less smear layer (d) sample of Group IV|
Click here to view
| Discussion|| |
The smear layer contains organic and inorganic substances that include fragments of odontoblastic processes, microorganisms, and necrotic materials. When viewed under the SEM, the smear layer often has an amorphous irregular and granular appearance. It may act as a substrate for bacteria, allowing their deeper penetration in the dentinal tubules. It can act as a barrier between filling materials and the canal wall and therefore compromise the formation of a satisfactory seal. Therefore, endodontic treatment should not be limited to the removal of pulp remnants and the widening of root canals, but should also focus on smear layer removal. Various chemicals, lasers, and chelating agents have been recommended for chemical and mechanical debridement during root canal treatment for the removal of the smear layer.
In the present study, we used 30 G needle tips, which can penetrate more deeply into the apical third and also controlled the flow rate of irrigants used. Flow rate is considered a highly significant factor in determining the flow pattern in irrigation dynamics and has been shown to influence the replacement of the irrigant., NaOCl 3% was used for the cleaning and shaping between each instrument, which acts on organic matter but has very little effect on inorganic components of smear layer.
In the present study, all the irrigants removed the smear layer effectively from coronal and middle third with statistically no significant difference between them. In apical third, canal diameter is narrower than middle and coronal third, more over apical region has complex anatomy which further prevents the proper contact of irrigant to canal wall in the apical region. Therefore, at apical third region, significant difference in mean smear layer score was obtained. Similar results were obtained in the studies conducted by Kuruvilla et al., and Zhou et al., where they found no statistically significant difference among the irrigants used to remove smear layer at coronal and middle third of root canal. In contrast to this study, Attur et al. found a statistically significant difference between 17% EDTA and 7% maleic acid and 17% EDTA and 2% chlorhexidine at coronal and middle third of the root canal. Group III (Chloroquick) has the least smear layer score in the apical third region as compared to other groups.
Chloroquick is a combination of stabilized sodium hypochlorite solution with buffer and etidronic acid. Sodium hypochlorite removes the organic portion of smear layer and necrotic debris, whereas etidronic acid removes the inorganic portion of smear layer due to its soft-chelating action. This combination has better tissue dissolution capacity by keeping the hypochlorite-hypochlorous acid equilibrium toward hypochlorite. EDTA acts on inorganic material by reacting with calcium ions in dentine, resulting in calcium chelation, promoting decalcification of dentine but has no effect on organic portion. EDTA is less efficient in narrow portions of the canal, requires a long application time for optimum results and can seriously damage the dentin causing erosion of the dentinal tubules. Furthermore, EDTA interferes with the organic tissue dissolution properties and antimicrobial efficacy of sodium hypochlorite. Carbonated water does not show chelating action and has no effect on organic portion of smear layer, it only dissolves smear layer. Normal saline when used alone produces a sludge layer made up of residual debris that occluded the dentinal tubules. Hence, maximum smear layer score was recorded in Group IV (normal saline).
The result of the current study is in accordance with Hegde and Thakkar and De-Deus et al., Hegde verified that chloroquick shows better removal of smear layer and does not significantly change the structure of dentin. De-Dues et al. demonstrated that soft chelating irrigation (HEBP) protocol optimizes bonding quality of the sealer because of better opening of dentinal tubules which were covered with smear layer.
In contrast to the present study, Patil et al. revealed that EDTA in combination with NaOCl and surfactant proved superior to chloroquick solution. This finding might be attributed to synergistic effect of combination of EDTA and NaOCl along with surfactant as final rinse. Solution modified with surfactants had significantly lower surface tension than its normal composition, thereby increasing their adaption to dentin and penetration into the dentinal tubules. Similarly Paqué et al. verified that hypochlorite-compatible chelator can reduce but not completely prevent hard-tissue debris accumulation during rotary root canal instrumentation. This result can be attributed to the use of complex mesial root canal systems of mandibular molars for the experiment. It is conceivable that microorganisms remaining in canal fins and ramifications after instrumentation may be protected by accumulated hard-tissue debris from disinfectants that are applied into the main root canal system.
The null hypothesis for this study was rejected as there was statistically significant difference observed in smear layer removal at apical third of the root canal. Chloroquick was better in removing smear layer at the apical third followed by EDTA and then carbonated water. No statistically significant result was seen at coronal and middle third of the root canal.
Further, long-term clinical studies are necessary to confirm these results and evaluate their significance to treatment outcome. Moreover, the present study was conducted in vitro, so the results may vary if it is conducted in vivo as there are so many variables in the oral environment which may affect the actions of agents used in the root canal system.
| Conclusion|| |
All irrigants could remove the smear layer from coronal and middle third of root canal, more or less equally but the difference exits at apical third. Within the limitations of this study it may be concluded that chloroquick was effective in removing the smear layer from apical third, more efficiently compared with other irrigants as it removes both organic and inorganic parts of smear layer because of soft chelating action. It is followed by EDTA which only removes the inorganic portion of smear layer followed by carbonated water which only dissolves the smear layer.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Guerisoli DM, Marchesan MA, Walmsley AD, Lumley PJ, Pecora JD. Evaluation of smear layer removal by EDTAC and sodium hypochlorite with ultrasonic agitation. Int Endod J 2002;35:418-21.
Ballal NV, Kandian S, Mala K, Bhat KS, Acharya S. Comparison of the efficacy of maleic acid and ethylenediaminetetraacetic acid in smear layer removal from instrumentated human root canal. A scanning electron microscopic study. J Endod 2009;35:1573-105.
Mohammadi Z, Shalavi S, Jafarzadeh H. Ethylenediaminetetraacetic acid in endodontics. Eur J Dent 2013;7:S135-42.
Wu L, Mu Y, Deng X, Zhang S, Zhou D. Comparison of the effect of four decalcifying agents combined with 60°C 3% sodium hypochlorite on smear layer removal. J Endod 2012;38:381-4.
Feldman M, Richardson CT. Histamine H2-receptor antagonists. Adv Intern Med 1978;23:1-24.
Hegde V, Thakkar P. Effect of continuous soft chelating irrigation protocol on removal of smear layer. Endodontology 2019;31:63-7. [Full text]
Cobankara FK, Erdogan H, Hamurcu M. Effects of chelating agents on the mineral content of root canal dentin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;112:e149-54.
Arias-Moliz MT, Ordinola-Zapata R, Baca P, Ruiz-Linares M, Ferrer-Luque CM. Antimicrobial activity of a sodium hypochlorite/etidronic acid irrigant solution. J Endod 2014;40:1999-2002.
Paqué F, Rechenberg DK, Zehnder M. Reduction of hard-tissue debris accumulation during rotary root canal instrumentation by etidronic acid in a sodium hypochlorite irrigant. J Endod 2012;38:692-5.
Lottanti S, Gautschi H, Sener B, Zehnder M. Effects of ethylenediaminetetraacetic, etidronic and peracetic acid irrigation on human root dentine and the smear layer. Int Endod J 2009;42:335-43.
Karale R, Odedra KM, Srirekha A, Champa C, Shetty A, Pushpalatha S, et al
. Effect of dentin on the antimicrobial efficacy of 3% sodium hypochlorite, 2% chlorhexidine, 17% ethylenediaminetetraacetic acid, and 18% etidronic acid on Candida albicans: An in vitro
study. J Conserv Dent 2016;19:455-60.
] [Full text]
van der Sluis LW, Wu MK, Wesselink PR. The efficacy of ultrasonic irrigation to remove artificially placed dentine debris from human root canals prepared using instruments of varying taper. Int Endod J 2005;38:764-8.
Torabinejad M, Handysides R, Khademi AA, Bakland LK. Clinical implications of the smear layer in endodontics: A review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;94:658-66.
Pashley DH. Smear layer: Overview of structure and function. Proc Finn Dent Soc 1992;88 Suppl 1:215-24.
Brännström M, Nordenvall KJ, Glantz PO. The effect of EDTA-containing surface-active solutions on the morphology of prepared dentin: An in vivo
study. J Dent Res 1980;59:1127-31.
George S, Kishen A, Song KP. The role of environmental changes on monospecies biofilm formation on root canal wall by Enterococcus faecalis. J Endod 2005;31:867-72.
Lester KS, Boyde A. Scanning electron microscopy of instrumented, irrigated and filled root canals. Br Dent J 1977;143:359-67.
Tilton JN. Fluid and particle dynamics. In: Perry RH, Green DW, Maloney JO, editors. Perry's Chemical Engineer's Handbook. 7th
ed. New York, USA: McGraw-Hill; 1999. p. 1-50.
Gopikrishna V, Sibi S, Archana D, Pradeep Kumar AR, Narayanan L. An in vivo
assessment of the influence of needle gauges on endodontic irrigation flow rate. J Conserv Dent 2016;19:189-93.
] [Full text]
Bystrom A, Sundqvist G. The antibacterial action of sodium hypochlorite and EDTA in 60 cases of endodontic therapy. Int Endod J 1985;18:35-40.
Kuruvilla A, Jaganath BM, Krishnegowda SC, Ramachandra PK, Johns DA, Abraham A. A comparative evaluation of smear layer removal by using edta, etidronic acid, and maleic acid as root canal irrigants: An in vitro
scanning electron microscopic study. J Conserv Dent 2015;18:247-51.
] [Full text]
Zhou H, Li Q, Wei L, Huang S, Zhao S. A comparative scanning electron microscopy evaluation of smear layer removal with chitosan and MTAD. Niger J Clin Pract 2018;21:76-80.
] [Full text]
Attur K, Joy MT, Karim R, Anil Kumar VJ, Deepika C, Ahmed H. Comparative analysis of endodontic smear layer removal efficacy of 17% ethylenediaminetetraacetic acid, 7% maliec acid, and 2% chlorhexidine using scanning electron microscope: An in vitro
study. J Int Soc Prevent Communit Dent 2016;6 Suppl S2:160-5.
De-Deus G, Zehnder M, Reis C, Fidel S, Fidel RA, Galan J Jr., et al
. Longitudinal co-site optical microscopy study on the chelating ability of etidronate and EDTA using a comparative single-tooth model. J Endod 2008;34:71-5.
De-Deus G, Namen F, Galan J Jr., Zehnder M. Soft chelating irrigation protocol optimizes bonding quality of Resilon/epiphany root fillings. J Endod 2008;34:703-5.
Patil PH, Gulve MN, Kolhe SJ, Samuel RM, Aher GB. Efficacy of new irrigating solution on smear layer removal in apical third of root canal: A scanning electron microscope study. J Conserv Dent 2018;21:190-3.
] [Full text]
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10]