Long-term prognosis for teeth with external cervical resorption based on periapical images and cone beam CT: A clinical study.

AIM: To evaluate whether supplemental information from CBCT changed long-term prognosis for teeth with external cervical resorption (ECR) compared to periapical (PA) images. Furthermore, to assess predictive findings in PA images and evaluate which findings in CBCT affected the long-term prognosis of teeth with ECR. METHODOLOGY: One hundred and ninty-four patients, mean age 41.2, range 13-81, having 244 teeth with ECR were included. An initial long-term prognosis determined either good or poor was established based on intraoral images. Afterwards, the patients underwent CBCT, and final long-term prognosis was decided. From the PA images and CBCT, ECR using Heithersay's classification system, pulp involvement and extension of ECR was assessed. In CBCT, the number of surface lesion(s) was additionally assessed. Descriptive statistics evaluated changes in long-term prognosis after CBCT. Logistic regression analyses tested if findings in PA images and CBCT affected the long-term prognosis. RESULTS: Based on CBCT, out of 244 teeth the long-term prognosis was assessed to be poor for 173 (70.9%) teeth and good for 71 (29.1%) teeth. The long-term prognosis changed in 76 (31.1%) teeth after CBCT; 5 (2.0%) changed from poor to good, and 71 (29%) changed from good to poor long-term prognosis. In 81 (33.2%) teeth the H-class increased, and in 10 (4.1%) teeth the H-class decreased after assessing CBCT. In 70 (28.7%) teeth, there was a change from no pulp involvement to involvement of the pulp after CBCT; eight (3.3%) teeth changed in the opposite direction. H-class 2 and 4 in PA images significantly increased the probability for a change in long-term prognosis compared to an H-class 3 (p < .05). H-class 4, pulp involvement, ECR in the oral 1/3 of the root, and more than two surface lesions seen in CBCT significantly influenced a poor long-term prognosis (p < .05). CONCLUSIONS: Supplemental information from CBCT changed long-term prognosis in almost one third of teeth with ECR. In most cases, the long-term prognosis changed from good to poor. H-class 3 in PA images had a significant influence on change in long-term prognosis. Several findings in CBCT influenced a poor long-term prognosis.

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.

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.

Surgical repair of external cervical resorption - Prognosis and prognostic factors.

Background/purpose: External cervical resorption (ECR) is an aggressive form of root resorption, which etiology is unclear and its prognosis remains unpredictable. The purpose of this study was to investigate the prognosis and potential prognostic factors of ECR-affected teeth after surgical intervention for external repair with/without root canal treatment. Materials and methods: Treated ECR cases from 2009 to 2019 were collected retrospectively. The survival of the teeth and the status of root resorption were assessed during the follow-up period. Potential prognostic factors were analyzed with log-rank test and Kaplan-Meier statistics. Results: A total of 42 treated ECR-affected teeth were enrolled. The two-year survival rate was 71.20% [54.16%, 93.59%]. Persistent root resorption was the main complication after treatment. Patients with multiple ECR-affected teeth had greater recurrent potential than patients with solitary ECR-affected teeth. Prolonged calcium hydroxide dressing may contribute to a more favorable clinical outcome. Gender, age, tooth position and the need for root canal treatment did not show statistically significant effect on the prognosis. Conclusion: The current surgical method was able to arrest ECR in most cases. However, the case type (the number of ECR-affected teeth per patient) could highly affect the prognosis of the teeth. Clinicians should consider long-term calcium hydroxide dressing in case of pulp involvement to achieve better results.

Delayed replantation of avulsed permanent maxillary central incisor: Case report with 6-year follow-up.

Replantation should be attempted in any case of avulsion, be it immediate or delayed. Retention of the replanted tooth helps in preservation of adjacent alveolar bone. Despite the occurrence of replacement resorption, the tooth can stay healthy and functional in the arch for a longer duration.

Multiple External Cervical Resorption Lesions in Patient with Graft versus Host Disease Treated with Systemic Bleomycin: A Case Report.

The phenomenon of multiple external cervical root resorption (ECRR) lesions in a single patient is rare but may have a link with the chemotherapeutic agent bleomycin. This case details an adult male with multiple ECRR lesions that developed following chemotherapy. His treatment regimen for Hodgkin's lymphoma included the chemotherapeutic antibiotic bleomycin, which has previously been linked with development of multiple ECRR lesions. The patient developed graft versus host disease following an allogeneic stem cell transplant, which could have a significant role in the development and promotion of the ECRR lesions. In total, 8 teeth developed ECRR, and all the known causative factors were excluded when examined. To our knowledge, this is only the second reported case in the literature to link bleomycin to multiple ECRR lesions. This case report aims to bring the reader's attention to the fact that multiple cervical resorption lesions can develop simultaneously. These lesions can be difficult to diagnose and treat and are often misdiagnosed as caries. Finally, the reader should consider the possible role of bleomycin and graft versus host disease in development of multiple lesions of ECRR.

Conservative management of an advanced external cervical resorption with internal approach using bio-ceramic materials: A case report.

Key clinical message: A successful management of an advanced external cervical resorption using a conservative approach with CBCT, dental operating microscope, and a new bio-ceramic material. Abstract: External cervical resorption (ECR) is a pathologic condition that is initiated on the external aspect of the root, below the epithelial attachment in the cervical position. This article will report a case of external cervical resorption (ESR) in an advanced stage, which was asymptomatic and was incidentally detected in a follow-up radiograph after the end of orthodontic treatment. Cone-beam computed tomography (CBCT) was prescribed to accurately diagnose the resorptive lesion and differentiate it from internal root resorption (IRR), and the final diagnosis was Heithersay's class IV ECR. Considering the health of the periodontium and the absence of attachment loss, it was decided to use a conservative internal approach to the management of this case. After the treatment, the patient was asymptomatic and the radiographic examinations showed no signs of peri-radicular pathology during the follow-up period. With the correct case selection and the availability of the appropriate materials and equipment such as a dental operating microscope (DOM) and bio-ceramic materials, the internal approach can be a successful and minimally invasive treatment, even for the management of advanced ECR cases.

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.

Biomechanically and Periodontally-Based Orthodontic Treatment of a Patient with Upper Canine Affected by External Cervical Resorption (ECR): A Case Report.

(1) Background: Orthodontic treatment may be a potential predisposing factor for ECR. The affected tooth goes to ankylosis, which could lead to a malocclusion. Although teeth severely affected by ECR (class IV Heithersay) are usually extracted, this case report aims to present the use of an ECR class IV upper canine, both as ankylosed to solve the malocclusion and the occlusal plane canting, as well as not ankylosed to correct its ridge defect with orthodontic extrusion. (2) Methods: A 14-year-old male, complaining of an ugly smile and a failed orthodontic attempt to recover an impacted canine, was referred to the orthodontic clinic. He was diagnosed with class II right subdivision, midline deviation, both upper and lower occlusal plane canting, and an upper left canine, previously impacted, showing ECR class IV. The treatment first included canting resolution with a cantilever and a spring, exploiting the anchorage offered by the ankylosed ECR canine. Then, a coronectomy, endodontic treatment, and orthodontic extrusion of that canine were performed to obtain the implant site development. (3) Results: Clinical and radiographic outcomes showed normocclusion and better bony conditions for safer implant placement in the aesthetic zone. (4) Conclusions: The high aesthetics and the periodontal and bony conditions obtained are probably not achievable by other therapeutic alternatives.

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.

A Cone-beam Computed Tomography Evaluation of External Invasive Resorption of Unerupted Teeth. Report of Three Cases.

Tooth resorption can occur either physiologically or pathologically and can be classified as internal or external. The term "external invasive resorption" (EIR) has been used to describe lesions originating from any surface defect exposing dentin. The absence of bacterial contamination, an intact pulp space, and a lesion consisting mainly of fibrovascular tissue characterize EIR. This study presents three cases of invasive resorption in unerupted teeth, emphasizing the importance of cone-beam computed tomography (CBCT). In two cases, the primary defect localized on the enamel surface, while in the third case, the focal point of the defect was not clear. CBCT provided detailed visualization of the resorption lesion's size and its relationship with surrounding structures, enhancing the diagnosis of EIR. Histological analysis of the third case confirmed the initial diagnosis. Invasive resorption can occur due to any surface defect in the case of unerupted teeth. Further research and correlation between radiographic and histological analysis are essential for the detection and classification systems in unerupted teeth.

Reporte de caso: reabsorción cervical externa / Case report: external cervical resorption

La reabsorción cervical externa es una patología poco frecuente y difícil de detectar, lo que complica el diagnóstico y pronóstico. El proceso destructivo provoca pérdida progresiva de tejido, comenzando en la superficie radicular y avanzando hacia la pulpa. Este tipo de reabsorción ocurre principalmente en la región cervical de la raíz dental pudiendo confundirse con lesión de caries radicular. El objetivo del reporte de caso es ilustrar al equipo de salud la existencia de esta condición y destacar la importancia del diagnóstico temprano y diferencial para evitar llegar a la pérdida del diente afectado.

External cervical resorption is a rare and difficult-to-detect condition, which complicates diagnosis and prognosis. The destructive process causes progressive loss of tissue, starting at the root surface and advancing towards the pulp. This type of resorption primarily occurs in the cervical region of the dental root and can be confused with root caries. The case report aims to inform the healthcare team about the presence of this condition and emphasizes the significance of early and differential diagnosis to prevent the loss of the affected tooth.

Evaluating the Effect of Different Intra-Orifice Barriers and Various Bleaching Agents on the Fracture Resistance of Teeth After the Walking Bleach Procedure: An In Vitro Study.

Objective This study aimed to evaluate the effect of three different commercially available intra-orifice barriers and bleaching agents on root canal-treated teeth. Materials and methods Forty-five freshly extracted single-rooted incisors, canine, and premolars were collected and stored in 10% formalin. Root canal procedures were performed on the extracted teeth and these were classified into three groups and three subgroups (n=5). Group 1: resin-modified glass ionomer cement (RMGIC); placed at the level of cemento-enamel junction (CEJ) and cured for 20 seconds. Group 2: BiodentinTM (Septodont Ltd., Saint Maur des Fausse´s, France); powder and liquid were mixed according to the manufacturer's instructions and placed at the level of CEJ, and waited for 15 minutes to set. Group 3: bulk-fill composite; placed at the level of CEJ. Group A was treated with 35% carbamide peroxide (Ultradent Opalescence 35% PF regular). Group B was bleached with 35% hydrogen peroxide (Pola Office). Group C, which was the control group, was treated with distilled water. The bleaching procedure was repeated once every seven days for a period of three weeks. After bleaching, every sample was sectioned 2 mm above the level of CEJ to remove the crown. Auniversal testing machine (UTM) was used for the evaluation of the fracture resistance of teeth. Data were analyzed for significance by using analysis of variance (ANOVA) and further pair-wise comparison was performed by pos-hoc analysis. The level of significance was set at p<0.05 Results There was a significant difference between the fracture resistance of the three materials when bleached using distilled water (p<0.05). The fracture resistance of Group 3 was significantly greater than that of Group 2 and Group 1 (p<0.05). The difference in the fracture resistance between Group 1 and Group 2 was nonsignificant (p>0.05). Conclusion Walking bleach performed via bleaching agents 35% carbamide peroxide and 35% hydrogen peroxide leads to a reduction in the fracture resistance of endodontically treated teeth; 35% hydrogen peroxide causes more fracture resistance reduction than carbamide peroxide of the same concentration. The presence of intra-orifice barriers leads to greater fracture resistance and reinforcement of endodontically treated teeth that undergo the walking bleach procedure. Bulk-fill composite can be used as an intra-orifice barrier with good fracture resistance.

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 (Altair Engineering Inc, Troy, MI) served as the 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, Biodentine, glass ionomer cement, and Bioaggregate. On all the models, a force of 100 N was applied on the palatal aspect 2 mm incisal to the cingulum directed at 45° along the long axis of the tooth. RESULTS: The stresses generated in dentin and cementum are less, with a restorative material having a high Young's modulus. For the 1Bd defect, MTA and Bioaggregate showed least stresses in dentin and cementum, respectively, whereas Biodentine had consistently lower stresses in dentin and cementum. Larger defects like 2Bd and 3Bd restored with Bioaggregate exhibited minimum stresses in dentin and cementum. CONCLUSIONS: 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.

Is External Cervical Resorption an Established Manifestation of Systemic Sclerosis? A Case Report.

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. 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. 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. 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 1-Year Outcome with Evaluation of the Heithersay and Patel Classification Systems.

INTRODUCTION: The purpose of this study was to identify possible associations between classification, treatment, and 1-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 12-year period. Information regarding demographics, predisposing factors, lesion classification, treatment, and outcomes were collected and analyzed. Inter- and intraobserver reliability analyses were conducted for both classification systems. RESULTS: There were 72 cases with at least 1 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 1-year outcome and either classification or treatment done. The weighted reliability analysis showed substantial agreement in both classification systems for both inter- and intraobserver agreement. There was a significant association between the 2 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 1 year after diagnosis. The Patel 3-dimensional 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.

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.

External Cervical Resorption: A Volumetric Analysis on Evolution of Defects over Time.

INTRODUCTION: The aim of this study was to assess the temporal evolution of external cervical resorption (ECR) defects using a volumetric quantification method. METHODS: Cone-beam computed tomographic (CBCT) images of patients diagnosed with ECR who chose not to receive treatment and attended recalls were collected. ECR defects were segmented in CBCT images at baseline and recall, and their volumes were quantified. The volumetric ratio of resorption defects/teeth was calculated. Three-dimensional classification of defects at baseline and recall and the prevalence of root surface perforations ≥1 mm were determined. The Wilcoxon matched pairs signed rank test, chi-square test, and linear regression models were used to analyze the data. RESULTS: Fifteen patients with 20 teeth diagnosed with ECR and an average recall time of 21 months were included. Nine (45%) teeth showed a change in 3-dimensional classification at recall. The volume of resorption defects (P = .0001) and the volumetric ratio of resorption defects/teeth (P = .0001) increased over time. The prevalence of root surface perforations ≥1 mm was higher at recall (n = 17, 85%) compared with baseline (n = 9, 45%) (P = .008). Linear regression models showed significant associations between the resorption defect volume at recall compared with baseline (P < .0001; 95% confidence interval, 0.053-0.081) and the volumetric ratio of resorption defects/teeth at recall compared with baseline (P < .0001; 95% confidence interval, 0.205-0.356). There was no association between the volume of resorption defects at recall with the length of the recall period, sex, or age (P > .05). CONCLUSIONS: When left untreated, ECR defects can increase in size and develop more root surface perforations. ECR has a dynamic nature, and its volumetric increase over time does not result from uniform/linear expansion of the defects.

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.

Avaliação da prevalência de trinca, fratura e reabsorção cervical externa pré e durante a pandemia da Covid-19: um estudo coorte retrospectivo / Evaluation of the prevalence of cracks, fractures and external cervical reabortion before and during the Covid-19 pandemic: a retrospective cohort study

Evidências emergentes mostram que a pandemia teve impactos significativos na saúde mental, provocando aumento da ansiedade e maior isolamento social devido às políticas de distanciamento físico introduzidas para controlar a doença. Um dos relatos mais frequentes dos cirurgiões-dentistas na pandemia foi o aumento do número de casos de pacientes com bruxismo e apertamento. Em consequência, observou-se acentuado número de casos de trincas e fraturas. Outra possível consequência do quadro de bruxismo e apertamento dos pacientes é a ocorrência de reabsorção cervical externa. O objetivo deste estudo é avaliar o número de casos com a presença de fratura, trinca e reabsorção cervical externa antes, durante e pós pandemia da COVID-19. Os dados foram obtidos através de tomografia computadorizada cone beam no centro de radiologia Slice, uma clínica particular de radiologia referência em endodontia na cidade de Belo Horizonte Minas Gerais, Brasil. O presente estudo observou um aumento no número de casos de trinca e fratura nos anos de 2020, 2021 e 2022. Os casos de reabsorção cervical externa apresentaram um aumento nos anos de 2021 e 2022. A pandemia da COVID-19 trouxe várias consequências negativas para a população, dentre elas o aumento da ansiedade e do estresse, que estão diretamente relacionados com o hábito do bruxismo e apertamento dental, consequentemente os casos de trincas, fraturas e reabsorção cervical externa aumentaram.

Emerging evidence shows that the pandemic has had significant impacts on mental health, causing increased anxiety and greater social isolation due to physical distancing policies introduced to control the disease. One of the most frequent reports from dental surgeons during the pandemic was the increase in the number of cases of patients with bruxism and clenching. As a result, a high number of cases of cracks and fractures were observed. Another possible consequence of patients' bruxism and clenching is the occurrence of external cervical resorption. The objective of this study is to evaluate the number of cases with the presence of fractures, cracks and external cervical resorption before, during and after the COVID-19 pandemic. The data were obtained through cone beam computed tomography at the Slice radiology center, a private radiology clinic that is a reference in endodontics in the city of Belo Horizonte Minas Gerais, Brazil. The present study observed an increase in the number of crack and fracture cases in 2020, 2021 and 2022. Cases of external cervical resorption increased in 2021 and 2022. The COVID-19 pandemic brought several negative consequences for the population, among them the increase in anxiety and stress, which are directly related to the habit of bruxism and clenching teeth, consequently the cases of cracks, fractures and external cervical resorption have increased.