Article type : Original Scientific Article

Accepted Article
European Society of Endodontology Position Statement:

External Cervical Resorption

European Society of Endodontology (ESE) developed by:

Patel S1,2, Lambrechts P3 ,Shemesh H4, Mavridou A3

Further contributions and revisions were made by ESE Executive Board members: PMH

Dummer, H Duncan, V Franco D Ørstavik, L Tjäderhane, J Whitworth.

1Endodontic Postgraduate Unit, King’s College London Dental Institute, London, UK, 245

Wimpole Street, London, UK, 3Conservative Dentistry, KU Leuven, Leuven, Belgium, and

4Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands,

Key words: external cervical resorption, CBCT, guidelines, Endodontology

Running head: Position statement on ECR

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doi: 10.1111/iej.13008
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 Correspondence:

PMH Dummer
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CEO of the European Society of Endodontology, Postboks 1237 Vika, 0110 Oslo, Norway

E-mail: ceo@e-s-e.eu

Abstract

This Position Statement represents a consensus of an expert committee convened by the

European Society of Endodontology (ESE) on External Cervical Resorption (ECR). The statement

is based on current clinical and scientific evidence as well as the expertise of the committee. The

primary aim is to provide the clinician with evidence-based criteria on aetiology,

histopathology, clinical presentation and management of ECR, and also to highlight areas where

there is minimal evidence. Previously published review articles provide more detailed

background information and the basis for this position statement (International Endodontic

Journal doi: 10.1111/iej.12942, 2018, International Endodontic Journal doi: 10.1111/iej.12946,

2018). It is intended that this position statement will be updated at appropriate intervals, as

further evidence emerges.

Introduction

ECR usually starts in the cervical region of the affected tooth and initially involves only the

periodontal ligament, cementum and dentine. However, in more advanced stages the pulpal

tissues may also become involved (Luso & Luder 2012, Mavridou et al. 2016a, Navid & Saberi

2018).

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 Until recently, the majority of the literature on this topic has been individual case (series)

reports focusing either on the possible aetiology and/or treatment options. Literature on
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histopathology and diagnosis is limited (Mavridou et al. 2017a, b) contributing to the risk of

inappropriate diagnosis and suboptimal management (Patel et al. 2018a, b).

Aetiology

For ECR to occur and propagate, it is assumed that there must be damage to the periodontal

ligament (PDL) and cementum, in combination with a stimulating factor that can induce and

maintain the activity of clastic cells (Marvidou et al. 2017a, b). The aetiology of ECR is poorly

understood and there may be aetiological factors which have not yet been identified. Previous

history of dental trauma and/or orthodontic treatment are the factors most commonly

associated with ECR (Tronstad 1988, Heithersay 1999, Marvidou et al. 2017a). However, more

research is required to confirm the cause and effect relationship of these suggested aetiological

factors (Patel et al. 2018a).

Histopathogenesis

It is well established that ECR is a complex and dynamic process (Luso & Luder 2012,

Mavridou et al. 2016a, 2017b), consisting of 3 main stages; resorptive (initiation),

resorptive (propagation) and reparative (remodeling) (Mavridou et al. 2016a, 2017b).

Resorption and repair can occur in parallel in different areas of the same lesion.

Increased understanding of the pathophysiology may ultimately result in strategies to

prevent and/or control the disease process.

Clinical presentation

The most commonly affected teeth are maxillary incisors, canines, first molars and mandibular

first molars (Mavridou et al. 2017a).

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 The presenting features of ECR are highly variable and dependent on several factors including

location and degree of progression (Patel et al. 2018a). It commonly presents as an incidental
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finding on clinical and radiographic examination, though there may be clinical signs of localised

gingival inflammation and bleeding, pulpal involvement, or in more advanced cases apical

periodontitis (Bergmans et al. 2002, Patel et al. 2009a, Bhuva et al. 2011).

Highly vascularized lesions involving the supracoronal regions of teeth may appear as pink

spots though other lesions such as advanced areas of internal resorption extending into

supragingival tissues may also present in this way. ECR may also be be mistaken clinically and

radiographically for cervical caries. However, high quality evidence on the clinical presentation

of ECR, as well as on its rate of progression, is lacking.

Radiographic assessment

There is no ‘classic’ radiographic appearance of ECR. The lesions may be radiolucent

(resorptive phase), radiopaque (reparative phase) or present as a combination of both

depending on the stage of the ECR lesion. To differentiate ECR from internal

inflammatory resorption, the outline of the root canal walls should be traceable through

the lesion on periapical radiographs. The parallax imaging technique can be used to

distinguish ECR from internal resorption as well as confirming the location of ECR

lesions, which are not detectable clinically by probing.

The limitations of periapical radiographs are well documented (Bender et al. 1961, Patel et al.

2009b), and can result in misdiagnosis and/or poor management of ECR (Schwartz et al. 2010,

Gunst et al. 2013, Vaz de Souza et al. 2017).

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 CBCT overcomes the limitations of periapical radiographs (Abella et al. 2012, Hashem et al.

2013, Rodriguez et al. 2017a, b) and can improve the diagnosis and/or management of ECR, by
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giving the clinician a precise appreciation of the nature and extent of the lesion, i.e. 3D

morphology, degree of circumferential spread and proximity to the root canal (Mavridou et al.

2016b, Patel et al. 2016, 2017).

The European Society of Endodontology position statement on CBCT (ESE 2014) highlights the

relevance of CBCT for the management of potentially restorable ECR lesions. The radiation dose

of a small field of view CBCT scan is relatively low when compared to computed tomography,

and is in the same order of magnitude as multiple parallax radiographs (Loubele et al. 2009,

Pauwels et al. 2012); this justifies its use for ECR diagnosis and follow up. CBCT is

recommended when the diagnosis is unclear, and/or treatment is being planned for ECR.

The Heithersay classification of ECR is based on 2-dimensional imaging, resulting in

underestimation and/or inadequate appreciation of the true extent of the resorptive

process (Heithersay 1999, Vaz de Souza et al. 2017). The Patel classification is 3-

dimensional, based on periapical radiographs and CBCT (Patel et al. 2018b). The aim of

this descriptive classification is to ensure an accurate diagnosis and aid communication

of ECR between clinicians. In the future, it should allow objective outcome assessment,

aid in decision making and in formulating a treatment plan that is likely to be successful

(Figure 1). Ultimately, treatment outcome and prognostic factors may also be assessed

in relation to the 3-dimensional nature of ECR (Patel et al. 2018b).

As with any device emitting ionizing radiation, the benefits of the CBCT scan must outweigh the

risks (ICRP 2007, ESE 2014). The ALARA principle (`as low as reasonably achievable’) must be

applied.

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 Treatment

The aim of treatment is to retain affected teeth in a healthy and functional state, and,
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when indicated, improve aesthetics (Patel et al. 2018c).

The objectives of treatment are elimination of the resorptive tissue, sealing of the

resultant defect and portal of entry and prevention of recurrence.

Treatment options for ECR depend on the extent, nature and accessibility of the

resorptive process; in some cases, a mucoperiosteal flap may have to be raised. The

treatment options include (Table 1):

 External repair of the resorptive defect +/- endodontic treatment

Excavation of the resorptive defect and restoration of the defect with a direct

restoration, for example, Patel class 1Ad, 2Ad, 2Bd). Root canal treatment may be

indicated if there is (probable) pulp involvment, for example, Patel class 1Ap,

2Ap, 2Bp).

 Internal repair and root canal treatment

Root canal treatment, excavation and restoration of the resorptive defect with a

direct plastic restoration, for example, Patel class 2Cp, 2Dp, 3Cp, 3Dp).

 Intentional replantation

Extraction of an endodontically treated tooth to allow restoration and/or

recontouring of an otherwise inaccesible ECR defect, followed by reinsertion, for

example, Patel class 3Ad, 3Bd.

 Periodic review

Untreatable teeth may be reviewed on a periodic basis, for example Patel class 2-

4Dd, 2-4Dp, or cases with significant reparative tissue within the ECR lesion.

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  Extraction

Indicated when ECR is inaccessible for treatment, or when the lesion is so

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extensive that the tooth may not be restored to satisfactory function or

aesthetics.

More research is required to assess the impact of these management options on the outcome of

treatment, as well as prognostic factors which may impact on the survival rate of affected teeth.

Prognosis

ECR lesions that are accessible and therefore ammenable to conservative treatment have a good

prognosis. However, patients should be advised of the limited evidence on treatment outcomes.

Research is required to assess the impact of the size and stage of the lesion (resorptive versus

reparative) on the outcome of treatment.

Conclusion

The clinical and radiographic presentation of ECR is highly variable with no classic presentation.

The current evidence confirms that periapical radiography has significant limitations in

accurately assessing the extent and nature of ECR and formulating an appropriate treatment

plan. Therefore, CBCT is recommended when considering treatment of potentially treatable ECR

lesions. Further high quality research is required to support the evidence base in all aspects of

ECR from its pathophysiology to effective clinical management.

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 References

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Accepted Article
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 Vaz de Souza D, Schirru E, Mannocci F, Foschi F, Patel S (2017) External cervical resorption: a

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and periapical radiographs. Journal of Endodontics 43, 121-5.

Table 1 Treatment options for ECR

• external repair of the resorptive defect +/_endodontic treatment

• internal repair and root canal treatment

• intentional replantation

• periodic review (untreatable teeth)

• extraction (untreatable teeth)

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ccepted Articl

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination
and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi:
10.1111/iej.13008
This article is protected by copyright. All rights reserved.
ccepted Articl
Figure Legend

Figure 1 A 3 dimensional classification for ECR

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