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References

Pintor AV, Dos Santos MR, Ferreira DM Does smear layer removal influence root canal therapy outcome? A systematic review. J Clin Pediatr Dent. 2016; 40:1-7 https://doi.org/10.17796/1053-4628-40.1.1
Mader CL, Baumgartner JC, Peters DD Scanning electron microscopic investigation of the smeared layer on root canal walls. J Endod. 1984; 10:477-483 https://doi.org/10.1016/S0099-2399(84)80204-6
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; 94:658-666 https://doi.org/10.1067/moe.2002.128962
Brannstrom M Smear layer: pathological and treatment considerations. Oper Dent Suppl. 1984; 3:35-42
Nygaard B Chelation in root canal therapy: ethylenediaminetetraacetic acid for cleansing and widening of root canals. Odontologisk tidskrift. 1957; 65:3-11
Vemuri S, Kolanu SK, Varri S Effect of different final irrigating solutions on smear layer removal in apical third of root canal: A scanning electron microscope study. J Conserv Dent. 2016; 19:87-90 https://doi.org/10.4103/0972-0707.173207
Ng YL, Mann V, Gulabivala K A prospective study of the factors affecting outcomes of nonsurgical root canal treatment: part 1: periapical health. International endodontic journal. 2011; 44:583-609 https://doi.org/10.1111/j.1365-2591.2011.01872.x
Shahravan A, Haghdoost AA, Adl A Effect of smear layer on sealing ability of canal obturation: a systematic review and meta-analysis. J Endod. 2007; 33:96-105 https://doi.org/10.1016/j.joen.2006.10.007
De-Deus G, Reis C, Paciornik S Critical appraisal of published smear layerremoval studies: methodological issues. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2011; 112:531-543 https://doi.org/10.1016/j.tripleo.2011.01.046
American Association of Endodontists. Root canal irrigants and disinfectants. 2011. https://www.aae.org/specialty/wp-content/uploads/sites/2/2017/07/rootcanalirrigantsdisinfectants.pdf
Darcey J, Jawad S, Taylor C Modern endodontic principles part 4: irrigation. Dent Update. 2016; 43:20-30 https://doi.org/10.12968/denu.2016.43.1.20
Boutsioukis C, Arias-Moliz MT Present status and future directions - irrigants and irrigation methods. International endodontic journal. 2022; 55:588-612 https://doi.org/10.1111/iej.13739
Virdee SS, Seymour DW, Farnell D Efficacy of irrigant activation techniques in removing intracanal smear layer and debris from mature permanent teeth: a systematic review and meta-analysis. Intern endodon J. 2018; 51:605-621 https://doi.org/10.1111/iej.12877
Giardino L, Del Fabbro M, Cesario F Antimicrobial effectiveness of combinations of oxidant and chelating agents in infected dentine: an ex vivo confocal laser scanning microscopy study. Intern endodon J. 2018; 51:448-456 https://doi.org/10.1111/iej.12863
Clarkson RM, Podlich HM, Moule AJ Influence of ethylenediaminetetraacetic acid on the active chlorine content of sodium hypochlorite solutions when mixed in various proportions. J Endod. 2011; 37:538-543 https://doi.org/10.1016/j.joen.2011.01.018
Baumgartner JC, Ibay AC The chemical reactions of irrigants used for root canal debridement. J Endod. 1987; 13:47-51 https://doi.org/10.1016/S0099-2399(87)80153-X
Mohammadi Z, Shalavi S, Jafarzadeh H Ethylenediaminetetraacetic acid in endodontics. Eur J Dent. 2013; 7:S135-S142 https://doi.org/10.4103/1305-7456.119091
Moness Ali AM, Raab WH Smear layer removal efficiency using apple vinegar: An in vitro scanning electron microscope study. Am J Dent. 2019; 32:21-27
Silva PV, Guedes DF, Nakadi FV Chitosan: a new solution for removal of smear layer after root canal instrumentation. Intern endodon J. 2013; 46:332-338 https://doi.org/10.1111/j.1365-2591.2012.02119.x
Ballal NV, Ferrer-Luque CM, Sona M Evaluation of final irrigation regimens with maleic acid for smear layer removal and wettability of root canal sealer. Acta Odontol Scand. 2018; 76:199-203 https://doi.org/10.1080/00016357.2017.1402208
Ballal NV, Kandian S, Mala K Comparison of the efficacy of maleic acid and ethylenediaminetetraacetic acid in smear layer removal from instrumented human root canal: a scanning electron microscopic study. J Endod. 2009; 35:1573-1576 https://doi.org/10.1016/j.joen.2009.07.021
Perez-Heredia M, Ferrer-Luque CM, Gonzalez-Rodriguez MP Decalcifying effect of 15% EDTA, 15% citric acid, 5% phosphoric acid and 2.5% sodium hypochlorite on root canal dentine. Intern endodon J. 2008; 41:418-423 https://doi.org/10.1111/j.1365-2591.2007.01371.x
Vertucci FJ Root canal morphology and its relationship to endodontic procedures. Endodontic Topics. 2005; 10:3-29 https://doi.org/10.1111/j.1601-1546.2005.00129.x
Garberoglio R, Becce C Smear layer removal by root canal irrigants. A comparative scanning electron microscopic study. Oral Surg Oral Med Oral Pathol. 1994; 78:359-367 https://doi.org/10.1016/0030-4220(94)90069-8
De Deus QD Frequency, location, and direction of the lateral, secondary, and accessory canals. J Endod. 1975; 1:361-366 https://doi.org/10.1016/s0099-2399(75)80211-1
Torabinejad M, Khademi AA, Babagoli J A new solution for the removal of the smear layer. J Endod. 2003; 29:170-175 https://doi.org/10.1097/00004770-200303000-00002
Boutsioukis C, Lambrianidis T, Kastrinakis E Irrigant flow within a prepared root canal using various flow rates: a Computational Fluid Dynamics study. Intern endodon J. 2009; 42:144-155 https://doi.org/10.1111/j.1365-2591.2008.01503.x
Khedmat S, Shokouhinejad N Comparison of the efficacy of three chelating agents in smear layer removal. J Endod. 2008; 34:599-602 https://doi.org/10.1016/j.joen.2008.02.023
Andrabi SM, Kumar A, Kumar Tewari R An in vitro SEM study on the effectiveness of smear layer removal of four different irrigations. Iran Endod J. 2012; 7:171-176
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; 31:590-592 https://doi.org/10.1097/01.don.0000152300.44990.6d
Giardino L, Del Fabbro M, Morra M Dual Rinse((R)) HEDP increases the surface tension of NaOCl but may increase its dentin disinfection efficacy. Odontology. 2019; 107:521-529 https://doi.org/10.1007/s10266-019-00436-4
Duncan HF, Kirkevang LL, Peters OA Treatment of pulpal and apical disease: The European Society of Endodontology (ESE) S3-level clinical practice guideline. Intern endodon J. 2023; 56:238-295 https://doi.org/10.1111/iej.13974
Calt S, Serper A Time-dependent effects of EDTA on dentin structures. J Endod. 2002; 28:17-19 https://doi.org/10.1097/00004770-200201000-00004
Tay FR, Gutmann JL, Pashley DH Microporous, demineralized collagen matrices in intact radicular dentin created by commonly used calcium-depleting endodontic irrigants. J Endod. 2007; 33:1086-1090 https://doi.org/10.1016/j.joen.2007.04.017
Mohammadi Z, Shalavi S, Yaripour S Smear layer removing ability of root canal irrigation solutions: a review. J Contemp Dent Pract. 2019; 20:395-402
Violich DR, Chandler NP The smear layer in endodontics – a review. Intern endodon J. 2010; 43:2-15 https://doi.org/10.1111/j.1365-2591.2009.01627.x
Hulsmann M, Heckendorff M, Lennon A Chelating agents in root canal treatment: mode of action and indications for their use. Intern endodon J. 2003; 36:810-830 https://doi.org/10.1111/j.1365-2591.2003.00754.x
Kumar Y, Lohar J, Bhat S Comparative evaluation of demineralization of radicular dentin with 17% ethylenediaminetetraacetic acid, 10% citric acid, and MTAD at different time intervals: An in vitro study. J Int Soc Prev Community Dent. 2016; 6:44-48 https://doi.org/10.4103/2231-0762.175412
Qian W, Shen Y, Haapasalo M Quantitative analysis of the effect of irrigant solution sequences on dentin erosion. J Endod. 2011; 37:1437-1441 https://doi.org/10.1016/j.joen.2011.06.005
Tay FR, Pashley DH, Loushine RJ Ultrastructure of smear layer-covered intraradicular dentin after irrigation with BioPure MTAD. J Endod. 2006; 32:218-221 https://doi.org/10.1016/j.joen.2005.10.035

Smear layer management in endodontics: An update on commonly available materials

From Volume 52, Issue 5, May 2025 | Pages 318-324

Authors

Edward Longbottom

BDS, PDDS, FHEA (UK), MClinEndo, Clinical Lecturer in Restorative Dentistry, Undergraduate Endodontic Lead, Cardiff University, University Dental Hospital Wales, Cardiff.

Articles by Edward Longbottom

Email Edward Longbottom

Petros Mylonas

BDS, MMedEd, PhD (Lond), MJDF RCS (Eng) MFDS RCPS (Glasg), FHEA (UK)

BDS, PDDS, FHEA (UK), MClinEndo, Clinical Lecturer in Restorative Dentistry, Undergraduate Endodontic Lead, Cardiff University, University Dental Hospital Wales, Cardiff.

Articles by Petros Mylonas

N Vasudev Ballal

BDS, PDDS, FHEA (UK), MClinEndo, Clinical Lecturer in Restorative Dentistry, Undergraduate Endodontic Lead, Cardiff University, University Dental Hospital Wales, Cardiff.

Articles by N Vasudev Ballal

Arindam Dutta

BDS, MDS, MFDS RCPS(Glasg)

BDS, PDDS, FHEA (UK), MClinEndo, Clinical Lecturer in Restorative Dentistry, Undergraduate Endodontic Lead, Cardiff University, University Dental Hospital Wales, Cardiff.

Articles by Arindam Dutta

Abstract

The smear layer is a thin layer of tooth tissue, bacteria and infected dentine that is intimately attached to the wall of root canals. It is created during any instrumentation of the root canal and inhibits microbe removal from dentine tubules and intimate attachment of endodontic sealer, which necessitates its removal. A variety of materials for removal of the smear layer is available: this article discusses the different types and makes general recommendations on the treatment of the smear layer and the use of chelating agents in endodontic treatment.

CPD/Clinical Relevance:

Removal of the smear layer is necessary for thorough disinfection of the root canal system and for the predictable healing of apical periodontitis.

Article

Within modern endodontics, there has been a gradual shift towards the total removal of the smear layer found within root canals. This paradigm shift in thinking is, however, backed up by little or no evidence on clinical outcome.1 For the most part, evidence is based on in vitro studies about sealers, microleakage and the idea that the bacteria left behind in the tubules and covered with this organic/inorganic smear layer may be viable and hence need eradicating.

The endodontic smear layer is a 1–2-µm thick, superficial layer attached to the canal wall as a result of canal instrumentation. Smear plugs can also be formed when the substance is forced in to the dentinal tubules to a depth of up to 40 µm.2 This layer contains a mixture of both organic and inorganic dentine debris, as well as necrotic pulp tissue, odontoblast processes, bacteria and their by-products, coagulated proteins and blood cells.3 The smear layer may itself contain live bacteria and can provide protection for bacteria already present within the dentinal tubules.4

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