External cervical resorption: a three-dimensional classification

Stress distribution in endodontically treated external cervical resorption lesions restored with MTA and biodentine - A finite element analysis

Introduction

Root resorption poses a significant challenge in dental practice, with external cervical resorption (ECR) being a common manifestation. ECR is often asymptomatic until advanced stages, complicating its diagnosis and management. Various factors contribute to its etiology, ranging from trauma to orthodontic treatment. The classification system proposed by Patel et al. (2018) offers a comprehensive framework for characterizing ECR lesions based on location and extent. Treatment strategies for ECR involve a combination of endodontic intervention and restorative techniques, with bioactive materials like mineral trioxide aggregate (MTA) and Biodentine emerging as promising options. However, the biomechanical behavior of teeth restored with these materials in the context of ECR remains underexplored.

Materials and methods

This study utilized finite element analysis (FEA) to assess stress distribution in teeth with simulated ECR lesions of varying sizes and locations, restored with MTA or Biodentine. Three-dimensional models of maxillary central incisors were generated based on CBCT scans, incorporating periodontal ligament and surrounding bone structures. Eight experimental models representing different ECR configurations were created and subjected to FEA using Optistruct software based on dimensional classification given by Patel et al., in 2018, A70 M & A70B: 1Ap, A130 M & A130B: 1Bp, B70 M & B70B: 2Ap, B130 M & B130B: 2Bp. All the models were tested for stress distribution by restoring the lesions with either M: MTA or B: Biodentine. Oblique load of 100 N was applied at 45°angle to the long axis 2 mm lingual to incisal edge. vonMises Stress distribution in enamel, dentine, restoration and at all the interfaces were observed.

Results

The analysis revealed that both MTA and Biodentine restorations exhibited uniform stress distribution around ECR lesions, with no significant differences based on lesion location or size. Maximum stress concentrations were observed around the restorations, particularly in subcrestal lesions. However, overall stress levels were comparable between MTA and Biodentine restorations, indicating similar biomechanical performance.

Conclusion

Finite element analysis provides valuable insights into the biomechanical behavior of teeth with ECR lesions restored with MTA and Biodentine. Both materials exhibit similar stress distribution patterns and offer adequate reinforcement against mechanical forces. Clinicians can confidently utilize MTA or Biodentine in the management of ECR, considering their favorable biomechanical properties and clinical outcomes. Further research is necessary to validate these findings and optimize treatment protocols for ECR.

External Cervical Resorption Detected by Cone Beam Computed Tomography on an Immature, Unerupted Maxillary Second Premolar

Root resorption is a commonly recognized risk of orthodontic treatment and can range from minimal changes at the apex to aggressive and extensive erosion of tooth structure. The following report is aimed at presenting a rare case of idiopathic aggressive preeruptive root resorption in a maxillary second premolar of a young child prior to orthodontic force. During phase I orthodontic treatment, the maxillary premolar required surgical exposure with a bracket and chain to assist in its eruption. Before the exposure, a cone beam computed tomography (CBCT) was captured to aid in localizing the premolar and its relationship to vital structures. In addition to identifying relevant anatomy, the image also revealed an incidental finding of extensive external cervical root resorption. The risks, benefits, prognosis, and alternatives of continuing with surgical exposure of the affected premolar were presented to the guardian. The informed and consented decision was made to continue with the exposure and subsequent orthodontic treatment to align the tooth in the arch. Upon eruption to the occlusal plane, the tooth was amenable to endodontic pulp vitality testing, Endo Ice, and a follow-up CBCT. It was determined that there was advanced aggressive progression of the resorptive process. The Patel Classification 3Cd/Class 4 Heithersay ECR diagnosis and a poor prognosis ultimately resulted in the extraction of the tooth. Management of this case highlights a number of important clinical features including the rarity of advanced preeruptive idiopathic external cervical root resorption, a multidisciplinary approach (orthodontic, endodontic, and surgical) to diagnose and manage the ECR, and the importance of prescribing and acquisition of appropriate imaging to aid in the early diagnosis of the entity. This case report will add to the body of knowledge of a rare incidence of advanced ECR on a young patient with a nontraumatized, unerupted maxillary second premolar.

Influence of tube current and metal artifact reduction on the diagnosis of external cervical resorption in teeth adjacent to a dental implant in CBCT: an ex-vivo study

OBJECTIVES

This ex-vivo study aimed to assess the influence of tube current (mA) and metal artifact reduction (MAR) on the diagnosis of early external cervical resorption (EECR) in cone-beam computed tomography (CBCT) in the presence of an adjacent dental implant.

MATERIALS AND METHODS

Twenty-three single-rooted teeth were sectioned longitudinally and EECR was induced using a spherical drill and 5% nitric acid in 10 teeth. Each tooth was positioned in the socket of the lower right canine of a dry human mandible and CBCT scans were acquired using 90 kVp, voxel of 0.085 mm, field of view of 5 x 5 cm, and varying tube current (4, 8 or 12 mA), MAR (enabled or disabled) and implant conditions (with a zirconia implant in the socket of the lower right first premolar or without). Five oral radiologists evaluated the presence of EECR in a 5-point scale and the diagnostic values (area under the receiver operating characteristic curve - AUC, sensitivity, and specificity) were compared using multi-way Analysis of Variance (α = 0.05). Kappa test assessed intra-/inter-evaluator agreement.

RESULTS

The tube current only influenced the AUC values in the presence of the implant and when MAR disabled; in this case, 8 mA showed lower values (p<0.007). MAR did not influence the diagnostic values (p>0.05). In general, the presence of an implant reduced the AUC values (p<0.0001); sensitivity values with 8 mA and MAR disabled, and specificity values with 4 mA and MAR enabled and 8 mA regardless MAR were also decreased (p<0.0001).

CONCLUSIONS

Variations in tube current and MAR were unable to improve EECR detection, which was impaired by the presence of an adjacent implant.

CLINICAL RELEVANCE

Increasing tube current or activating MAR tool does not improve EECR diagnosis, which is hampered by the artifacts generated by dental implants.

Challenges in differential diagnosis and treatment of cervical root resorption vs. root caries

External cervical root resorption may be occasionally mistaken for root caries and vice versa. Radiographical and clinical differential diagnoses of cervical root resorption and root caries are essential for correct treatment planning and a successful treatment outcome. This article reviews the contemporary literature and summarises the prevailing professional consensus pertaining to external cervical root resorption. Clinical diagnostics which help distinguish cervical root resorption from root caries are outlined and treatment approaches of external cervical root resorption are discussed.

The various forms of tooth resorption

Tooth resorption refers to the loss of the organic and inorganic components of tooth structure by clastic cells. The complex and multifaceted nature of its aetiology, along with the several classification schemes published in the area, are likely to create confusion amongst researchers and clinicians, and may lead to compromised treatment decisions. Therefore, this paper will categorise and address tooth resorption based on aetiology in order to help clinicians diagnose and filter treatment options based on the pathophysiology of the resorption at hand. With recent advancements in the literature, the purpose of this paper is to provide clinicians with a current, clinically relevant summary of the various forms of tooth resorption, with a focus on aetiologically driven treatment strategies and suggestions that facilitate their recognition, diagnosis and management.

An Evaluation of the Fracture Resistance of Teeth with Simulated External Cervical Resorption Cavities Categorized Using Three-Dimensional Classification

(1) Background: External cervical resorption causes dental hard tissue destruction that may reduce the fracture resistance of affected teeth. By using a compressive strength test, this study aimed to evaluate the fracture resistance of teeth with simulated external cervical resorption cavities that have different three-dimensional classifications. (2) Methods: In total, 170 teeth with simulated external cervical resorptions were divided into 16 experimental groups (n = 10) and 1 control group (n = 10) based on the three-dimensional classification: 1Ap, 1Bp, 1Cp, 1Dp, 2Ap, 2Bp, 2Cp, 2Dp, 3Ap, 3Bp, 3Cp, 3Dp, 4Ap, 4Bp, 4Cp, 4Dp and a control group. Defects were restored with mineral trioxide aggregate. The fracture resistances of the samples were statistically analyzed using two-way repeated ANOVA and the Bonferroni correction for multiple comparisons at a significance level of p < 0.05. (3) Results: The lowest resistance to fracture was observed in samples with vertical height level "4" and circumferential spread of "D" (p < 0.001). In the groups with circumferential spreads "B", "C" and "D", there were significant differences between the samples with vertical height levels "1", "2", "3" and "4" regarding fracture resistance (p < 0.001). (4) Conclusions: The circumferential spread and vertical height of the external cervical resorption influenced the fracture resistance of the affected teeth.

Root resorptions induced by genetic disorders: A systematic review

OBJECTIVES

Root resorption in permanent teeth is a common pathological process that often follows dental trauma or orthodontic treatment. More rarely, root resorption is a feature of genetic disorders and can help with diagnosis. Thus, the present review aims to determine which genetic disorders could induce pathological root resorptions and thus which mutated genes could be associated with them.

METHODS

We conducted a systematic review following the PRISMA guidelines. Articles describing root resorptions in patients with genetic disorders were included from PubMed, Embase, Web of Science, and Google Scholar. We synthesized the genetic disorder, the type, severity, and extent of the resorptions, as well as the other systemic and oral symptoms and histological features.

RESULTS

The synthetic analysis included 25 studies among 937 identified records. We analyzed 21 case reports, three case series, and one cohort study. Overall, we highlighted 14 different pathologies with described root resorptions. Depending on the pathology, the sites of resorption, their extent, and their severity showed differences.

CONCLUSION

With 14 genetic pathologies suspected to induce root resorptions, our findings are significant and enrich a previous classification. Among them, three metabolic disorders, three calcium-phosphorus metabolism disorders, and osteolysis disorders were identified.

Introducing a new auto edge detection technique capable of revealing cervical root resorption in CBCT scans with pronounced metallic artifacts

Cervical resorption is a serious threat to the longevity of the teeth. In this study, the Canny edge-detection algorithm was applied on CBCT images to compare the accuracy of original and Canny views for diagnosing cervical resorption in endodontically treated teeth. Intracanal metallic posts were inserted in 60 extracted teeth being randomly divided into three groups: control, 0.5 mm, and 1 mm cervical resorption. CBCT scans of the teeth were presented to three observers in both original and Canny formats with the accuracy being determined by receiver operating characteristic (ROC) analysis. The DeLong test was used for paired comparisons with the significance level set at 0.05. The highest accuracy belonged to Canny images in 1 mm resorption, followed by Canny images in 0.5 mm resorption, original images in 1 mm resorption, and original images in 0.5 mm resorption, respectively. The Canny images were significantly more accurate in the diagnosis of 0.5 mm (p < 0.001) and 1 mm (p = 0.009) resorption. Application of the Canny edge-detection algorithm could be suggested as a new technique for facilitating the diagnosis of cervical resorption in teeth that are negatively affected by metallic artifacts.

Prevalence and Characterization of External Cervical Resorption Using Cone Beam Computed Tomography

INTRODUCTION

The aim of this study was to assess the prevalence of external cervical resorption (ECR) and characterize the cases of ECR using cone beam computed tomography (CBCT).

METHODS

High-resolution CBCT scans of 6216 patients (2280 males and 3936 females), consecutively acquired during the period July 2021 to March 2022, were analyzed. Identified cases of ECR were characterized by 3 evaluators regarding lesion height, circumferential spread, portal of entry proximity to root canal, stage, location, and width.

RESULTS

In a total of 38 patients and 40 teeth, ECR cases demonstrated an incidence of 0.61%. The median age of the patients was 39 years. Prevalence of ERC was 0.78% among males and 0.50% among females. The most affected teeth were the maxillary incisors and canines. The most frequent characteristics of the lesion were: extension up to the cervical third (47.5%), more than 270° circumferential spread (42.55%), probable pulpal involvement (57.5%), progressive stage (65%), supracrestal (52.1%) and mesial (34.7%) localization of >1 mm in size (52.1%) portals of entry. Cases with greater longitudinal involvement also showed greater circumferential progression (P = .008). There was no association between portal of entry location and bone crest or ECR reparative phase (P = .42). Inter-rater agreement ranged from good to very good. No association between portal of entry and ECR progression was observed.

CONCLUSIONS

ECR showed low prevalence in the Brazilian population, affecting mostly anterior maxillary teeth of patients within a wide age range. CBCT allowed characterization of ECR lesions with good interobserver agreement.

Artificial Intelligence for Detection of External Cervical Resorption Using Label-Efficient Self-Supervised Learning Method

INTRODUCTION

The aim of this study was to leverage label-efficient self-supervised learning (SSL) to train a model that can detect ECR and differentiate it from caries.

METHODS

Periapical (PA) radiographs of teeth with ECR defects were collected. Two board-certified endodontists reviewed PA radiographs and cone beam computed tomographic (CBCT) images independently to determine presence of ECR (ground truth). Radiographic data were divided into 3 regions of interest (ROIs): healthy teeth, teeth with ECR, and teeth with caries. Nine contrastive SSL models (SimCLR v2, MoCo v2, BYOL, DINO, NNCLR, SwAV, MSN, Barlow Twins, and SimSiam) were implemented in the assessment alongside 7 baseline deep learning models (ResNet-18, ResNet-50, VGG16, DenseNet, MobileNetV2, ResNeXt-50, and InceptionV3). A 10-fold cross-validation strategy and a hold-out test set were employed for model evaluation. Model performance was assessed via various metrics including classification accuracy, precision, recall, and F1-score.

RESULTS

Included were 190 PA radiographs, composed of 470 ROIs. Results from 10-fold cross-validation demonstrated that most SSL models outperformed the transfer learning baseline models, with DINO achieving the highest mean accuracy (85.64 ± 4.56), significantly outperforming 13 other models (P < .05). DINO reached the highest test set (ie, 3 ROIs) accuracy (84.09%) while MoCo v2 exhibited the highest recall and F1-score (77.37% and 82.93%, respectively).

CONCLUSIONS

This study showed that AI can assist clinicians in detecting ECR and differentiating it from caries. Additionally, it introduced the application of SSL in detecting ECR, emphasizing that SSL-based models can outperform transfer learning baselines and reduce reliance on large, labeled datasets.

Evaluation of Fracture Strength after Repair of Cervical External Resorption Cavities with Different Materials

INTRODUCTION

The aim was to evaluate the stress distributions on dentin and repair materials caused by static force applied to teeth, with cervical external root resorption (CER) after repair with different materials using finite element analysis.

METHODS

This study was performed with the 3-dimensional finite element analysis method. Access cavity, root canal cavity dimensions, and supporting tissues other than cementum were modeled in the maxillary central tooth. The CER cavity was created on the labial side of the tooth model. The coronal side of the resorption cavity was restored with composite, and the radicular side with different materials (MTA, Biodentine, BioAggregate, calcium-enriched cement [CEM], glass ionomer cement [GIC], and resin-modified glass ionomer cement [RMGIC]). A static force of 300 N was applied to the palatal surface of the crown at an angle of 135° to the long axis of the tooth. The stress distributions in dentin and repair materials were analyzed.

RESULTS

The highest stress in dentin was seen in the fFigmodel with unrepaired CER. In the models repaired with MTA, GIC, and RMGIC, von Mises stress values in dentin were greater than for repairs with Biodentine, BioAggregate, and CEM materials. The von Mises stress on the repair materials applied to the root were highest for the BioAggregate material. This was followed by CEM, Biodentine, MTA, RMGIC, and GIC materials, respectively.

CONCLUSION

The repair of CER in the tooth significantly decreased the stress values in dentin. Biodentine, BioAggregate, and CEM absorbed more force and caused less stress to be transmitted to dentin compared to MTA, GIC, and RMGIC.

The consequences of Dental trauma

Traumatic dental injuries pose a variety of complex ongoing issues to the dental practitioner. As dental injuries are commonly experienced at a young age, the treatment often takes place during adolescence or early in adulthood years at crucial development stages and very early in the life of the permanent successor. Therefore, the ability to correctly diagnose the injury, and follow an appropriate management plan should increase practitioners' ability to improve both the outcomes of dental trauma and long-term prognosis of the tooth.The consequences of dental trauma can be explored by taking into consideration the type of injury, which enables an assessment of the degree of insult to the pulpal tissues, neurovascular bundle, periodontal ligament and cemental cells. This has a direct influence on post-trauma complications. Early intervention, where indicated, and appropriate follow-up utilising international guidelines is imperative to identify changing diagnoses and act accordingly. This review paper will discuss the classification of traumatic injuries and their associated outcomes with management strategies for emerging disease including potential endodontic and restorative complexities and when to refer to secondary care.

Effects of different treatment modalities on biomechanical behavior of maxillary incisors with external invasive cervical resorption at different progression levels

BACKGROUND/AIM

This study aimed to evaluate the biomechanical behavior of maxillary incisors with external invasive cervical resorption (EICR) at different progression levels after receiving different modes of treatment under occlusal forces using finite element analysis (FEA).

MATERIALS AND METHODS

Three-dimensional (3D) models of intact maxillary central incisors were constructed and modified to include EICR cavities with different progression levels in the buccal cervical areas. The EICR cavities confined to dentin were repaired using Biodentine™ (Septodont Ltd., Saint Maur des Fausse ́s, France), resin composite, or glass ionomer cement (GIC) . Additionally, EICR cavities with pulp invasion requiring direct pulp capping were simulated as repaired using Biodentine only or 1 mm thick Biodentine and either resin composite or GIC for the rest of the cavity. Moreover, models with root canal treatment and EICR defects repaired using Biodentine, resin composites, or GIC were also generated. A force of 240 N was applied to the incisal edge. The principal stresses in the dentin were evaluated.

RESULTS

GIC showed more favorable results than the other materials in EICR cavities confined to the dentin. However, Biodentine alone resulted in more favorable minimum principal stresses (Pmin ) compared to other materials in EICR cavities with close pulp proximity. Exceptionally, the models localized in the coronal third of the root with a circumferential extension of the cavity >90° showed more favorable results for GIC. The presence of root canal treatment had no significant effect on stress values.

CONCLUSIONS

Based on this FEA study the use of GIC in EICR lesions confined to the dentin is recommended. However, Biodentine may be a better option for restoring EICR lesions close to the pulp with or without root canal treatment. Except when the circumferential extension of the cavity is >90°, the use of GIC may be more advantageous.

Clinical management of external cervical resorption: A systematic review

This review investigated whether any therapeutic options influenced the outcome of treatment for teeth with external cervical resorption. Out of 870 articles identified by an electronic search, 60 clinical case reports and six case series were included. No randomised clinical trials were found. Risk of bias was assessed using Joanna Briggs Institute's tools. External surgical intervention was the preferred method of accessing the lesions. Removal of resorptive tissue was most often achieved mechanically. Bioactive endodontic cements were the preferred materials for restoring teeth. The outcome measures were based on clinical and radiographic parameters. Of the cases included in the review, no specific treatment approach had a superior outcome in relation to Heithersay's classification. Furthermore, due to the absence of randomised clinical trials, and the low level of evidence associated with case reports/case series, it was not possible to define the optimum clinical treatment for external cervical resorption.

Clinical and radiographic features of external cervical resorption - An observational study

AIM

To determine the prevalence of symptoms, clinical signs and radiographic presentation of external cervical resorption (ECR).

METHODOLOGY

This study involved 215 ECR lesions in 194 patients referred to the Endodontic postgraduate Unit at King's College London or Specialist Endodontic practice (London, UK). The clinical and radiographic findings (periapical [PA] and cone beam computed tomography [CBCT]) were readily accessible for evaluation. A checklist was used for data collection. Inferential analysis was carried out to determine if there was any potential association between type and location of tooth in the jaw as well as sex, age of the patient and ECR presentation and radiographic feature.

RESULTS

Eighty-eight patients (94 teeth) were female and 106 patients were male (121 teeth), the mean age (±SD) was 41.5 (±17.7) years. Fifteen patients (7.7%) had more than one ECR lesion. The most affected teeth were maxillary central incisors (21.4% [46 teeth]) and mandibular first molars (10.2% [22 teeth]). ECR was most commonly detected as an incidental radiographic finding in 58.1% [125 teeth] of the cases. ECR presented with symptoms of pulpal/periapical disease in 23.3% [n = 50] and clinical signs (e.g. pink spot, cavitation) in 16.7% [36 teeth] of the cases. Clinical signs such as cavitation (14%), pink spot (5.1%) and discolouration (2.8%) were uncommon, but their incidence increased up to 24.7% when combined with other clinical findings. ECR was detected in the resorptive and reparative phases in 70.2% and 29.8% of the cases respectively.

CONCLUSION

ECR appears to be quiescent in nature, the majority being asymptomatic and diagnosed incidentally from PA or CBCT. When assessed with the Patel classification, most lesions were minimal to moderate in relation to their height (1 or 2) and circumferential spread (A or B). However, the majority of ECRs were in (close) proximity to the pulp. Symptoms and clinical signs were associated with (probable) pulp involvement rather than the height and circumferential spread of the lesion. Clinical signs were more frequently associated when ECR affected multiple surfaces.

The prevalence, characteristics, and risk factors of external cervical resorption: a retrospective practice-based study

OBJECTIVES

External cervical root resorption (ECR) is a poorly understood and aggressive form of resorption. The purpose of this study was to examine the prevalence, characteristics, and risk factors associated with the occurrence of ECR in patients seeking endodontic care from private practice settings.

MATERIALS AND METHODS

Records of 343 patients with 390 teeth diagnosed with ECR were identified from 3 private endodontic practices from 2008 to 2022. The patients' demographic information, systemic conditions, and dental history were recorded. The characteristics of the cases including Heithersay classification, pulpal and periapical status, and their management were documented. The association between case severity and potential predisposing factors was examined using chi-square analysis.

RESULTS

The overall prevalence of ECR among patients seeking endodontic care was low (< 1%). However, there was a greater than twofold increase in the pooled prevalence from 2016 to 2021 (0.99%) compared to the data from 2010 to 2015 (0.46%). The most commonly affected teeth were anterior teeth (48.7%). Class II (30.0%) and class III (45.4%) defects were the most often identified. Patients with a history of trauma or orthodontic treatment were significantly more likely to be diagnosed with severe cervical resorption (class III or IV) (p < 0.05).

CONCLUSIONS

There has been an increase in the prevalence of ECR in patients seeking endodontic care. A history of orthodontic treatment and traumatic dental mechanical injuries may predict the severity of resorption.

CLINICAL RELEVANCE

The upward trend in the occurrence of ECR warrants close monitoring of the patients at high risk of developing the condition to facilitate early detection and management.

Repair of an Extensive External Cervical Resorption Lesion Using Intentional Replantation with Crown Rotation

Treatment of large external cervical resorption (ECR) lesions may be compromised, rendering the tooth unrestorable. Intentional replantation is a potential treatment option depending on the site and extent of ECR. We present a case of a large ECR successfully managed with intentional replantation with rotation of the tooth. The female patient consulted the hospital clinic, with an extensive palatal ECR on the maxillary lateral incisor. Routine planar radiographs and cone-beam computed tomography demonstrated a larger palatal than the ECR lesion (Heithersay Class III and Patel's Class 2Bp) not amenable to nonsurgical treatment. Intentional replantation after short-term extrusion was planned. The defect was restored, then a palatal ferrule was achieved by rotating the tooth by 180°. At the 18-month follow-up, the periradicular and periodontal tissues remained healthy, and no other symptoms were reported. In conclusion, this successful video-illustrated clinical case highlights the benefits of intentional replantation in saving teeth with advanced ECR.

Stresses in teeth with External Cervical Resorption defects restored with different Biomimetic cements: A Finite Element Analysis

INTRODUCTION

This study compared the stress distributions in teeth with simulated external cervical resorption defects restored with different restorative materials and identified areas of high stress concentration.

METHODS

A maxillary central incisor created in a scanned model using HyperWorks software served as control. External cervical resorption defects based on Shanon Patel's classification were created (1Bd/2Bd/3Bd) in the scanned model. The defects were restored using Mineral Trioxide Aggregate (MTA), Biodentine, Glass Ionomer Cement (GIC) and Bioaggregate. On all the models a force of 100 N was applied on palatal aspect, 2 mm incisal to cingulum directed at 45° along the long axis of the tooth.

RESULTS

The stresses generated in dentin and cementum is less, with a restorative material having high Young's modulus. For 1Bd defect, MTA and Bioaggregate showed least stresses in dentin and cementum respectively, whereas Biodentine had consistently lower stresses in dentin and cementum both. Larger defects like 2Bd and 3Bd restored with Bioaggregate exhibited minimum stresses in dentin and cementum.

CONCLUSION

Bioaggregate and Biodentine replace dentin with maximum stress and maximum strain. Elastic moduli similar to or higher than dentin are preferred for restoring cervical third resorptive lesions of the tooth.

Reprint of: Prevalence and Characteristics of Root Resorption Identified in Cone-Beam Computed Tomography Scans

INTRODUCTION

Root resorption is a destructive process that compromises tooth structure and can result in tooth loss. Often it remains asymptomatic and is an incidental finding on radiographic examinations. The purpose of this study was to determine prevalence and characteristics of root resorption in patients referred for cone-beam computed tomography (CBCT) imaging for a variety of indications.

METHODS

The study included CBCT scans of 1086 consecutive patients referred for CBCT imaging over an 18-month period. A total of 1148 scans were acquired. Data were abstracted from radiology reports, and prevalence estimates of resorption were computed for the aggregate sample and also across specific indications.

RESULTS

Resorption was identified in 171 patients (15.7%, 95% CI: 13.6%-17.9%) and in 249 teeth with a prevalence range of 2.6%-92.3% across specific indications. An 18.7% of the patients had 2 resorption sites whereas 8.8% had 3 or more resorption sites. The majority of affected teeth were anteriors (43.8%), followed by molars (40.6%) and premolars (14.5%). The most prevalent resorption types were external (29.3%), cervical (22.5%), infection-induced apical resorption (13.7%), internal (9.6%), and impacted tooth induced (8.8%). The majority of teeth with resorption did not have prior endodontic treatment (73.9%) and had radiographically normal periapex (69.5%). Of 249 teeth with resorption, 31% presented as incidental finding. The prevalence of incidental findings of resorption increased with age, P < .05, and was significantly lower for anterior teeth (20.2%) as compared to premolars (41.7%) and molars (36.6%), (P < .05).

CONCLUSION

The high proportion of incidental findings of resorption detected by CBCT suggests that resorption is not recognized/detected by conventional radiography and therefore remains underdiagnosed.

CBCT in contemporary endodontics

Cone-beam computed tomography (CBCT) is a three-dimensional imaging modality which can aid endodontic diagnosis and treatment planning. While there are guidelines available describing the indications, there are divergent philosophies on when this technology should be applied in clinical practice. This paper reviews the applications of CBCT including the clinical relevance of parameters which can be assessed, highlights the limitations of this technology, and provides guidance on how to maximise its clinical utility.

Dental Bleaching with Phthalocyanine Photosensitizers: Effects on Dentin Color and Collagen Content

With the increasing demand for tooth bleaching in esthetic dentistry, its safety has been the focus of a comprehensive body of literature. In this context, the aim of the present study was to evaluate the application effects of pentalysine β-carbonylphthalocyanine zinc (ZnPc(Lys)₅)-mediated photodynamic therapy in dentin bleaching and its effects on dentin collagen. We first established a new and reproducible tooth staining model using dentin blocks stained by Orange II and then bleached with ZnPc(Lys)₅ (25 μM) and hydrogen peroxide (10% or 30%). Data were analyzed with one- and two-way ANOVA and a significance level of p < 0.05. ZnPc(Lys)₅ effectively bleached the dentin samples to an extent comparable to hydrogen peroxide at either 10% or 30% concentrations. Further studies on the dentin morphology, chemical element distribution, and protein constituents, using an electron microscope, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and SDS-PAGE, demonstrated that treatment with the photosensitizer preserved the dentin structure and, at the same time, the major organic component, collagen type I. For comparison, hydrogen peroxide (10% or 30%) treatment significantly degraded the collagen protein. This work indicated that the photosensitizer exerts potent bleaching effects on dentin staining; importantly, does not damage dentin and its collagen content; and opens up a new strategy to further explore various photosensitizers for the bleaching of both tooth enamel and dentin.

IS EXTERNAL CERVICAL RESORPTION AN ESTABLISHED MANIFESTATION OF SYSTEMIC SCLEROSIS? A CASE REPORT

AIM

Scleroderma, or systemic sclerosis, is a multisystem autoimmune disorder characterized by hardening and fibrosis of the skin. To date, only a small number of case reports have established a relationship between scleroderma and external cervical resorption (ECR). The aim of this case report is to document the case of a patient with multiple external cervical resorption lesions, who was referred to our unit.

SUMMARY

A 54-year-old female patient, with a 10-year history of systemic sclerosis diagnosed by her rheumatologist, was referred to our unit regarding extensive ECR. A total of 14 maxillary and mandibular teeth with ECR were detected by clinical examination and cone-beam computed tomography (CBCT). The characteristic vascularity of resorptive defects with profuse bleeding upon probing was not evident. The patient declined any active treatment owing to the desire to avoid lengthy and unpredictable treatment, which may hasten the loss of her teeth.

CONCLUSIONS

General practitioners should be aware of the relationship between connective tissue disorders and ECR. Although not well established in the literature, the vascular changes implicated in scleroderma may stimulate the odontoclastic processes involved in ECR.

External Cervical Resorption: Relationships Between Classification, Treatment, and One-Year Outcome with Evaluation of the Heithersay and Patel Classification Systems

INTRO

The purpose of this study was to identify possible associations between classification, treatment, and one-year outcome of external cervical resorption (ECR) lesions using the Heithersay and Patel systems. Performance of the Patel 3-dimensional classification system was also evaluated.

METHODS

A chart review identified 142 cases of ECR over a twelve-year period. Information regarding demographics, predisposing factors, lesion classification, treatment, and outcomes were collected and analyzed. Inter- and intra-observer reliability analyses were conducted for both classification systems.

RESULTS

There were 72 cases with at least one year of follow up. 70% of these cases survived. Treatment recommendations were correlated with both Heithersay and Patel classification. There were no correlations found between one-year outcome and either classification or treatment done. The weighted reliability analysis showed substantial agreement in both classification systems for both inter- and intra-observer agreement. There was a significant association between the two systems, however the Heithersay system tended to underestimate the apical extent of the lesion.

CONCLUSIONS

Periodic review of ECR lesions presents as a viable treatment option, at least for one year after diagnosis. The Patel 3-D classification system is at least as effective as the Heithersay system and should be used in future ECR prognosis studies. Further long-term outcome assessments are still needed.

Histologic features of external cervical resorption affecting impacted maxillary canines. Report of two cases

Reports on the histopathologic features of external cervical resorption (ECR) in unerupted teeth are scarce. This article reports on 2 maxillary impacted canines from different patients that showed ECR lesions and were surgically removed and histologically evaluated. Case 1 showed symptoms associated with oral communication of the dental follicle and pulpal exposure. Radiographs and cone-beam computed tomographic imaging showed that resorption affected a large part of the root and the crown. Case 2 was asymptomatic, and the resorption cavity was restricted to the tooth crown. Both teeth were extracted and subjected to histologic processing and analysis. In case number 1, the coronal pulp was necrotic and infected, showing areas of exposure to the resorption channels. The apical pulp was vital and uninflamed. The pulp space was surrounded by a continuous pericanalar resorption-resistant sheet. Part of the resorbed area of dentin was occupied by inflamed granulation tissue. More apically, a network of trabecular bone was present in the resorbed area. In case number 2, the pulp around the resorbed area was uninflamed and vital. A large fraction of the lost dentin was replaced by trabecular bone, closely adapted to the irregularly resorbed dentin surface, and no inflammatory cells. Our findings indicate that impacted teeth with ECR may remain asymptomatic until associated with infection. Histologic features of resorption in impacted teeth were similar to those in erupted teeth. In the case associated with infection, the resorbed area was occupied by inflamed tissue and newly formed bone. In the case with no infection, the resorption area was filled with bone undergoing a remodeling process.

Intentional replantation and management of avulsion related ankylosis and external cervical resorption. A 10-year follow up case report

Replantation is the treatment of choice for avulsed permanent teeth; ankylosis and cervical root resorption are among survival complications. A 9.5-year-old boy presented with an avulsed maxillary permanent central incisor with an open root apex following a school accident. The tooth was kept in milk, after a dry time of 15-20 min. Its replantation was performed 60 min after the accident. At 8 months, apexification with apical plug was attempted upon radiographic evidence of apical periodontitis. Ankylosis sound with infraocclusion and radiographic evidence of external cervical root resorption (ECR) were evident at 3 years and 3 months. At the patient's return one year later with esthetic concerns (2 mm infraocclusion) there was a 5 mm diameter ECR cavity. After intentional atraumatic extraction the resorptive cavity was debrided and restored with Biodentine; subsequently the tooth was reimplanted and splinted at an extruded position. At the 10-year follow up since the first avulsion the tooth remains esthetically pleasing, asymptomatic, non-ankylotic and functional. The present case supports intentional replantation as an option in managing infraoccluded teeth with advanced ECR.

Prevalence and Characteristics of Root Resorption Identified in Cone-Beam Computed Tomography Scans

INTRODUCTION

Root resorption is a destructive process that compromises tooth structure and can result in tooth loss. Often it remains asymptomatic and is an incidental finding on radiographic examinations. The purpose of this study was to determine prevalence and characteristics of root resorption in patients referred for cone-beam computed tomography (CBCT) imaging for a variety of indications.

METHODS

The study included CBCT scans of 1086 consecutive patients referred for CBCT imaging over an 18-month period. A total of 1148 scans were acquired. Data were abstracted from radiology reports, and prevalence estimates of resorption were computed for the aggregate sample and also across specific indications.

RESULTS

Resorption was identified in 171 patients (15.7%, 95% CI: 13.6%-17.9%) and in 249 teeth with a prevalence range of 2.6%-92.3% across specific indications. An 18.7% of the patients had 2 resorption sites whereas 8.8% had 3 or more resorption sites. The majority of affected teeth were anteriors (43.8%), followed by molars (40.6%) and premolars (14.5%). The most prevalent resorption types were external (29.3%), cervical (22.5%), infection-induced apical resorption (13.7%), internal (9.6%), and impacted tooth induced (8.8%). The majority of teeth with resorption did not have prior endodontic treatment (73.9%) and had radiographically normal periapex (69.5%). Of 249 teeth with resorption, 31% presented as incidental finding. The prevalence of incidental findings of resorption increased with age, P < .05, and was significantly lower for anterior teeth (20.2%) as compared to premolars (41.7%) and molars (36.6%), (P < .05).

CONCLUSION

The high proportion of incidental findings of resorption detected by CBCT suggests that resorption is not recognized/detected by conventional radiography and therefore remains underdiagnosed.

Early detection of external cervical resorption in posterior teeth: a radiographic, cross-sectional study of an adolescent population

OBJECTIVES

To establish the prevalence and severity of external cervical resorption (ECR) in posterior teeth observed in bitewing (BW) radiographs in an epidemiological study of a 17-year-old patient population from community dentistry. Furthermore, to assess the potential predisposing factors for ECR.

METHODS

Posterior BWs from 5596 patients (2717 females, 2879 males; mean age 17.8 years) were assessed by three observers in order to detect ECR (using Heithersay's classification system, severity classes 1-4). When ECR was suspected, cone beam CT (CBCT) was offered to verify diagnosis. Prevalence was estimated based on ECR suspected in BWs and finally in CBCT. Possible predisposing factors (orthodontic treatment, trauma, and periodontal disease) were recorded and assessed for association with ECR.

RESULTS

In 41 patients, ECR was suspected in BWs (suspected prevalence 0.73%). 32 patients accepted CBCT examination, of which eight were verified to have ECR (final prevalence 0.18%). In 24 patients, other disease entities and abnormal tooth morphology, that had mimicked ECR in BWs, excluded ECR in CBCT. ECR severity ranged from class 1-3 in BW and 2-4 in CBCT. All but one case had not been diagnosed by the patient's community dentist. No statistically significant association between predisposing factors and ECR was identified.

CONCLUSIONS

ECR had low prevalence in this adolescent population, as observed in both BWs and CBCT. Still, early detection of ECR is important for treatment prognosis, and attention should be paid to this disease entity when assessing BWs obtained for other diagnostic purposes. CBCT may subsequently aid in verifying the disease.

Resistance to fracture of simulated external cervical resorption cavities repaired with different materials

The aim of the study was to evaluate the fracture resistance (FR) of teeth with simulated external cervical resorption (ECR) cavities repaired with different materials. Following the shaping of the 80 human permanent maxillary central incisors, standard ECR cavities were prepared and restored with a nanohybrid composite resin; a high viscosity GIC Equia Forte Fill; Biodentine; Biodentine + nanohybrid composite resin; MTA BIOREP; MTA BIOREP + nanohybrid composite resin. Then, the root canals were obturated with AH Plus and gutta-percha. The roots were embedded acrylic resin blocks and fracture strength test was applied. The highest FR was observed in the Biodentine group, while the lowest was in Equia group (p < 0.05). No significant results were observed among composite, Biodentine + composite, MTA BIOREP + composite and MTA BIOREP (p > 0.05). Biodentine may be a preferable material for repairing ECR cavities. Adding a composite layer on MTA BIOREP and Biodentine did not improve the FR of these materials.

Conservative Therapy of External Invasive Cervical Resorption with Adhesive Systems: A 6-Year Follow-Up Case Report and Literature Review

The diagnosis and treatment of external invasive cervical resorption (EICR) could be a challenging clinical situation even for the most experienced dentists. It is a fairly rare lesion and a poorly understood phenomenon, and its insidious and aggressive nature can lead to tooth loss. Even in the era of dental implants, trying to save a compromised tooth is imperative for any clinician. This report presents a case of an upper central incisor with a class II Heithersay EICR in which treatment was performed using a multidisciplinary approach and the defect was restored with resin composite. The surgery in which the defect was exposed and repaired was followed by an endodontic treatment and the placement of a fiber-reinforced post. In this case, the use of modern materials, such as resin composites, allowed not only the avoidance of tooth extraction but also the achievement of satisfactory aesthetic results. The 6-year follow-up demonstrated the success of therapy and the resolution of clinical symptoms. This case report highlights the importance of early detection of EICR and how composite resins could provide an effective and aesthetic restauration of the defect, which favors the health of the surrounding gingival tissue.

Present status and future directions: Root resorption

Root resorption is the loss of dental hard tissue because of odontoclastic action. In permanent teeth, it is undesirable and pathological in nature. Root resorption may occur on the inner aspect of the root canal (internal root resorption) or on the outer aspect of the root (external root resorption). Regardless of its location, root resorption is irreversible, and may result in discomfort for the patient, requires management and/or, in some cases, results in the premature loss of the affected tooth. Root resorption is often challenging to accurately diagnose and manage. The aim of this narrative review is to present the relevant literature on the aetiology, pathogenesis, diagnosis and management, as well as discuss the future directions of diagnosis and management of root resorption.

Tooth root resorption: A review

Tooth root resorption is multifactorial, leading to progressive destruction and eventual loss of tooth root dentin and cement. There are internal and external types of root resorption, each having its variety. The etiology and pathogenesis of tooth root resorption are poorly understood, and the most significant etiological factors are trauma, pulpal infection, tooth bleaching, and orthodontic treatment. Tooth root resorption is primarily asymptomatic; thus, it is revealed accidentally by radiographic examination. Progressive clinical manifestations are pain, tooth discoloration, tooth mobility, and other conditions. Awareness of the causes and risk factors allowing tooth root resorption, and regular radiographic examination, in case of necessity, make it possible to reveal resorption at an early stage and to prevent its further development. Thus, the aim of this study is to present etiopathogenesis, a clinical course, and diagnostic peculiarities of internal and external types of tooth root resorption, enabling practicing dentists to timely diagnose root resorption and take appropriate measures to avoid further complications. Within the limitation of this review, even though the etiopathogenesis of tooth root resorption is yet not fully understood, it is suggested that the etiological factors fall into two groups (endogenic and exogenic) to enhance further understanding of the possible causes and mechanisms of root resorption and allow practitioners to monitor high-risk patients and make timely diagnoses. Moreover, radiographic examination and CBCT are indispensable for the diagnosis of root resorption.

Influence of Cone-beam Computed Tomography in clinical decision-making among different specialists in External Cervical Resorption lesions: a before-after study

INTRODUCTION

Inadequate management of external cervical resorption (ECR) lesions may impact the treatment outcome. This study aimed to ascertain the influence of cone-beam computed tomography (CBCT) in clinical decision-making choices in cases of ECR among dentistry specialists (endodontics, prosthodontics, oral surgery, periodontics orthodontics, and general dentistry). A secondary objective was to evaluate the self-reported level of difficulty in choosing a treatment plan before and after viewing the CBCT images.

METHODS

Sixty examiners from different specialties were chosen to evaluate 12 cases of ECR lesions. Each case included clinical photographs, digital periapical (PA) radiographs, and a small-volume CBCT scan. In the first assessment, the examiners were given all the relevant information of each case, except the CBCT scan. Each examiner was asked to select 1 of the proposed treatment options and assess the difficulty of decision making. Four weeks later, the examiners randomly reviewed the same 12 cases with additional information from the CBCT data.

RESULTS

After the CBCT evaluation, the clinicians changed their treatment plan in 72.2% of the cases (P < .05). The self-reported level of difficulty in choosing a treatment changed in all groups after evaluating the CBCT scans (P< .05). After viewing the CBCT scan, the extraction option increased significantly in all groups (P < .05).

CONCLUSIONS

CBCT scan had a significant impact on clinical decision-making in cases of ECR evaluated by different specialists.

Tooth resorption-Part 2: A clinical classification

Tooth resorption is either a physiological or a pathological process resulting in loss of dentin and/or cementum. It may also be associated with bone loss. Currently there is no universal classification for the different types of tooth resorption. This lack of a universal classification leads to both confusion amongst practitioners and poor understanding of the resorptive processes occurring in teeth which can result in incorrect/inappropriate diagnoses and mis‐management. When developing a classification of diseases and/or conditions that occur within the body, several criteria should be followed to ensure a useful classification. The classification should not only include pathological conditions but also physiological conditions. Since tooth resorption can be either pathological or physiological, a classification of tooth resorption should include both of these categories. Any classification of diseases should be possible to use clinically, meaningful, useful, clear and universal. It should enable easy storage, retrieval and analysis of health information for evidenced‐based decision‐making. It should also be possible to share and compare data and information between different institutions, settings and countries. A classification of tooth resorption should be developed by combining anatomical, physiological and pathological approaches. For some types of resorption, the aetiological approach should also be incorporated. A classification of tooth resorption that uses simple, relevant and appropriate terminology based on the nature and location of the resorptive process occurring in teeth is proposed. There are two broad categories of internal and external tooth resorption which are sub‐divided into three types of internal tooth resorption (surface, inflammatory, replacement) and eight types of external tooth resorption (surface, inflammatory, replacement, invasive, pressure, orthodontic, physiological, idiopathic). The clinician's understanding, diagnosis and management of tooth resorption can be facilitated by using this simple classification which should ideally be used universally by the entire dental profession to ensure clarity and to avoid confusion.

External cervical resorption - Treatment outcomes and determinants: a retrospective cohort study with up to 10 years of follow-up

AIM

To assess long-term external cervical resorption (ECR) treatment outcomes in relation to both local and treatment-related determinants.

METHODOLOGY

Information was available for 76 patients (98 teeth) who were diagnosed with ECR during the period from 2008 to 2018 at the University of British Columbia graduate endodontics clinic. The ECR patients were followed-up, and a clinical and radiographic examination was conducted. Chi-Square test compared failure rates among different subgroups. The survival analysis was used to evaluate the overall ECR survival/failure rates in relation to several local and treatment-related determinants.

RESULTS

Overall, 67 patients (89 teeth) were followed-up. The mean follow-up time was 3.9 years, and the minimum was 1 year. Twenty-four teeth failed (19 extracted, 5 not functional), and the overall probability of failure was 50.0% 8 years after the diagnosis. Significant (p < 0.05) local ECR determinants were tooth location and the Heithersay classification, and treatment-related determinants were root canal treatment (RCT) and the ECR repair combined with RCT. Treatment outcomes for Heithersay class 1 and 2 cases were better than for class 3 and 4 cases.

CONCLUSIONS

Higher failure rates were associated with posterior tooth location and higher Heithersay class, while RCT and ECR repair combined with RCT were associated with lower failure rates.

Impact of cone beam CT on diagnosis of external cervical resorption: the severity of resorption assessed in periapical radiographs and cone beam CT. A prospective clinical study

OBJECTIVES

To compare the severity of external cervical resorption (ECR) observed in periapical (PA) images and cone beam CT (CBCT) using the Heithersay classification system and pulp involvement; and to assess inter- and intraobserver reproducibility for three observers.

METHODS

CBCT examination was performed in 245 teeth (in 190 patients, mean age 40 years, range 12-82) with ECR diagnosed in PA images. Three observers scored the severity of ECR using the Heithersay classification system (severity class 1-4) and pulp involvement (yes/no) in both PA images and CBCT. Percentage concordance and κ-statistics described observer variation in PA images and CBCT for both inter- and intraobserver reproducibility.

RESULTS

For all three observers, the ECR score was the same in the two modalities in more than half of cases (average 59%; obs1: 54%, obs2: 63%, obs3: 61%). However, in 38% (obs1: 44%, obs2: 33%, obs3: 36%) of the cases, the observers scored more severe ECR in CBCT than in PA images (p < 0.001). The ECR score changed to a less severe score in CBCT only in 3% (obs1: 1%, obs2: 4%, obs3: 4%). For pulp involvement, 14% (obs1: 7%, obs2: 20%, obs3: 15%) of the cases changed from "no" in PA images to "yes" in CBCT. In general, κ values were higher for CBCT than for PA images for both the Heithersay classification score and pulp involvement.

CONCLUSIONS

ECR was generally scored as more severe in CBCT than PA images using the Heithersay classification and also more cases had pulp involvement in CBCT.

A clinical approach strategy for the diagnosis, treatment and evaluation of external cervical resorption

AIM

To propose a clinical approach strategy on the diagnosis, treatment, and evaluation of external cervical tooth resorption (ECR) cases. To investigate and discuss the outcome of this approach.

METHODOLOGY

A clinical approach strategy on ECR was developed based on a retrospective observation study of 542 teeth. 47 teeth were excluded due to lack of clinical/radiographical information, and 182 were immediately extracted. This approach had three steps: diagnosis, treatment planning, and evaluation. During diagnosis, the medical, dental history and clinical/radiographical characteristics were evaluated. Depending on the resorption extent, ECR cases were categorized into four classes according to Heithersay's classification. During treatment planning, a treatment decision flowchart was prepared based on four main decisive criteria: probing feasibility, pain, location and extent of resorption (class), and existence of bonelike tissue. Three treatment options were applied: a) extraction, b) monitoring, or c) conservative treatment by external, internal, or combination of internal-external treatments. During evaluation, assessment of ECR progression, tooth survival and other factors like esthetics and periodontal attachment were performed. Descriptive statistical analysis of the outcome for up to ten years (for the overall clinical approach and for each individual treatment decision), was carried out with OriginLabs OriginPro 9 and Microsoft Excel 365.

RESULTS

A three-step strategy was developed on how to deal with ECR cases. Indicative examples of each treatment decision were presented and discussed. The overall survival rate of this strategy was 84.6% (3 years), 70.3% (5 years), 42.7% (8 years) and 28.6% (10 years). Higher survival rate was observed for external treatment decision than for internal. The success of each treatment decision depended on the extent of the resorption (class). The success of a treatment decision should be based on the long-term outcome, as a different evolution can be observed with time.

CONCLUSIONS

A clinical approach strategy was introduced on ECR pathosis. This strategy was not solely based on ECR class, as other important decisive criteria were considered. This step-wise approach, has a 70.3% survival rate with a mean of 5 years. This work will hopefully provide an incentive for a broader collaboration, to potentially establish a universally accepted ECR treatment strategy.

Survey based assessment of diagnosis through periapical radiograph and CBCT and treatment of root resorption with Brazilian and American dentists and endodontists

Background

This study assesses and compares the knowledge level of endodontists (ENDs) and general dental practitioners (GPs) from Brazil and United States of America (USA) in the diagnosis and treatment of internal and external inflammatory root resorptions through periapical radiographic (PA) and cone beam computed tomography (CBCT) examinations.

Material and Methods

A cross-sectional online questionnaire-based survey was presented to the volunteers containing questions regarding personal and professional profile, as well as three clinical cases of internal and external inflammatory root resorption. A series of multiple-choice questions about the diagnosis and treatment options were surveyed. The data collected was analysed by the Chi-square test with Yates correction with a significance level of 5 %.

Results

Most answers were considered adequate when all three questions about the diagnosis and all two questions relating to the treatment were answered accurately. A total of 374 dentists answered the survey (n: 229 from Brazil vs. 145 from USA) being 41% END and 59% GP. END presented higher level of knowledge than GP regarding to diagnosis and treatment of inflammatory root resorptions both in Brazil and USA (p<0.05); USA presented higher level of adequate responses than Brazil (p<0.05).

Conclusions

END achieved a level of knowledge of the diagnosis and treatment of root resorption superior to the GP. Comparing the results obtained in both countries, it was observed that the USA had a higher correct response rate than Brazil. Key words:Internal root resorption, external root resorption, management, diagnosis, treatment.

External cervical resorption: Radiological diagnosis and literature (Review)

External cervical resorption (ECR) is a relatively unknown and insidious pathology characterized by the loss of hard dental tissues such as: Enamel, cementum and dentine due to clastic function. It begins as a localized resorptive process that initiates on the area of the root beneath the epithelial attachment and the coronal part of the alveolar process, involving vital and non-vital tissues. Despite the fact that there are several potential predisposing factors related to ECR, its aetiology still remains poorly understood and more research is needed to establish the cause-and-effect relationship of all the etiological factors. Improved radiographic detection using cone-beam computed tomography (CBCT) is required in order to correctly classify and assess this entity. This provides a three-dimensional insight into the lesion, regarding the location, the size, the depth and the circumferential spread of the ECR defect. It also allows establishment of the most efficacious treatment plan and management. The purpose of this literature review is to cover the relevant literature concerning the etiology, pathogenesis, clinical and radiological presentation and management of ECRs (based on the CBCT findings).

Comparison of imaging modalities in the diagnosis of external cervical resorption (ECR): an in-vitro study

External cervical resorption is a pathological condition affecting the cervical margins of teeth. Due to the increased prevalence and the area it affects, it can be easily misdiagnosed. The ability of clinicians to diagnose ECR and subcategorise the lesions using periapical radiographs and cone beam-CT scans has not been investigated in-depth. This study aims to assess if diagnostic ability to detect ECR lesions with the two modalities was different and if there was a change in the diagnosis when CBCT was used. A human skull, including the mandible was used for this study. The teeth were randomly allocated to the different subcategories, then pre and post-preparation radiographs with CBCT were taken. Statistical analysis was done using IBM SPSS version 16.0 (SPSS Inc., Chicago, IL, USA). The study sample was composed of 60 participants, the overall sensitivity of intraoral radiographs was significantly lower than CBCT. When the participants were told the radiograph and the CBCT were of the same tooth 60% said they would change their diagnosis. The use of intraoral radiographs alone might not be enough to identify and correctly diagnose ECR lesions. CBCT can give a better idea about the nature and the extent of the lesion.

A Bioinformatics Systems Biology Analysis of the Current Oral Proteomic Biomarkers and Implications for Diagnosis and Treatment of External Root Resorption

External root resorption (ERR) is a silent destructive phenomenon detrimental to dental health. ERR may have multiple etiologies such as infection, inflammation, traumatic injuries, pressure, mechanical stimulations, neoplastic conditions, systemic disorders, or idiopathic causes. Often, if undiagnosed and untreated, ERR can lead to the loss of the tooth or multiple teeth. Traditionally, clinicians have relied on radiographs and cone beam computed tomography (CBCT) images for the diagnosis of ERR; however, these techniques are not often precise or definitive and may require exposure of patients to more ionizing radiation than necessary. To overcome these shortcomings, there is an immense need to develop non-invasive approaches such as biomarker screening methods for rapid and precise diagnosis for ERR. In this review, we performed a literature survey for potential salivary or gingival crevicular fluid (GCF) proteomic biomarkers associated with ERR and analyzed the potential pathways leading to ERR. To the best of our knowledge, this is the first proteomics biomarker survey that connects ERR to body biofluids which represents a novel approach to diagnose and even monitor treatment progress for ERR.

A Review of External Cervical Resorption

External cervical resorption (ECR) is a relatively uncommon yet aggressive form of dental hard tissue destruction. It is initiated at the cervical aspect of the root surface and extends apicocoronally and circumferentially inside the dentin. Despite the large number of case reports and clinical studies that have investigated ECR, its etiology remains unclear. Recent advancements in clinical assessment measures, such as the use of cone-beam computed tomographic imaging, have provided additional insights into the nature of this lesion. This has facilitated the continued development and improvement of treatment methods for this condition. In this article, we provide an overview of the latest research pertaining to the etiology, histopathology, predisposing factors, diagnosis, classification, and treatment of ECR. Furthermore, we provide a summary of the different classification schemes for ECR and highlight the relevant therapeutic principles.

Management of severe traumatic intrusion in the permanent dentition

Traumatic intrusion is considered one of the most severe luxation injuries to the permanent dentition. There are limited studies based on minimal evidence supporting suggested management protocols, owing to the rare occurrence of intrusion. The following case report details the multidisciplinary management and 18-month follow-up, in line with current UK guidelines, of a 23-year old adult male who sustained severe intrusion injuries to both permanent maxillary central incisor teeth. Timely, accurate diagnosis and subsequent appropriate management correlates with improved outcomes for traumatic injuries and it is therefore imperative those involved with the acute and long-term management of dentoalveolar trauma are aware of current guidelines.

Detection of the internal anatomy of lower anterior teeth using cone-beam computed tomography

Morphology study of root canal systems is essential for a correct diagnosis, therapy and prognosis of root canal treatment. This study aimed to analyse the dental anatomy of the lower anterior teeth, using cone-beam computed tomography (CBCT). Lower anterior teeth were classified in terms of type, number and location of root canals, evaluating the bilaterality of anatomical occurrences and determining whether the gender and age influence the findings. We analysed 749 CBCT of patients attending the School of Dentistry for different reasons. Spearman's correlations and Wilcoxon signed-rank test were used to analyse data (α = 0.05). There was no significant correlation between gender (male and female) and anatomy of the canals 33 (P = 0.162), 32 (P = 0.815), 31 (P = 0.708), 41 (P = 0.422), 42 (P = 0.382) and 43 (P = 0.063). There was a significant correlation between age and anatomy of the canals 33 (P = 0.045), 32 (P = 0.033), 31 (P = 0.022), 41 (P = 0.000), 42 (P = 0.037) and 43 (P = 0.037). There was no significant correlation between gender and patients' age (P = 0.325). There was no anatomical difference between the bilateral pairs (right and left homologous teeth) (P > 0.05). The most common anatomical configuration was single-canal teeth (85.29%), followed by the configuration in which one canal leaves the chamber, divides into two and unite again (12.88%). Anatomy of the lateral incisors and lower canines does not change with the gender of patients. However, as age rises, single canals and the incidence of division into two canals ending in a single foramen also increases.

Non-Hodgkin Lymphoma Mimicking Endodontic Lesion: A Case Report with 3-dimensional Analysis, Segmentation, and Printing

Non-Hodgkin lymphoma (NHL) of the oral cavity can present with pain, swelling and radiolucent lesion mimicking endodontic diseases. This article reports on a case of diffuse large B-cell lymphoma initially diagnosed and treated as periodontal disease and then endodontic disease in the maxillary anterior and premolar area of a 40-year old female. A cone beam computed tomography (CBCT) image of the lesion was taken. The lesion was segmented using Mimics software (Materialise NV, Lueven, Belgium). Three-dimensional models of the tumor were printed. During the surgical phase teeth #4, 6, and 7 were extracted and biopsy samples were obtained. Histopathologic examination showed invasive sheets of large, atypical, basophilic cells strongly and diffusely positive for CD20. Three-dimensional analysis, segmentation, and printing of radiolucent lesions of the jaws assists with differential diagnosis and efficient treatment. Oral health professionals can play a crucial role in the early detection and diagnosis of oral NHL, thereby preventing extensive loss of function and esthetics, and even saving lives.