Bones heal, teeth don't! The involvement of dentists in the acute and long-term management of patients injured in the Manchester Arena Bomb.

This paper outlines the involvement of dentists in the treatment of patients following the terror attack at Manchester Arena on 22 May 2017. It predominantly describes the role of the authors - a paediatric dental consultant and maxillofacial surgery dental core trainee (DCT). As a result of the incident a number of patients suffered oro-facial injuries, with many treated at Central Manchester Foundation Trust Hospitals' Manchester Royal Infirmary and Royal Manchester Children's Hospital. The major incident response of the trust is discussed, as are the presentation of blast injuries and corresponding NHS guidance. Two paediatric cases present the role of the paediatric dental consultant in the acute, intermediate and long-term management of these patients. The presentation of unique dento-alveolar injuries in the context of other trauma and their subsequent treatment demanded true multidisciplinary management. The importance of teeth and oral health to physical and psycho-social wellbeing and recovery was clear and recognised by other teams involved in the patients' management. The experience reinforced the overall impact dental health has on physical and psycho-social health, and how a holistic approach is integral to treatment of major trauma.

Restoration of a large class IV fracture using direct composite resin: A clinical report.

Restoration of anterior tooth fractures is a common dental procedure. Both direct and indirect options are clinically acceptable to repair fractured teeth. For a large class IV fracture, treatment planning is time consuming, and the artistic skills necessary to achieve optimal results can be daunting. This clinical report describes a step-by-step protocol for achieving highly esthetic direct anterior restorations.

Classification and Epidemiology of Traumatic Dentoalveolar Injuries in Dogs and Cats: 959 Injuries in 660 Patient Visits (2004-2012).

The objective of this study was to determine the epidemiology of traumatic dentoalveolar injuries (TDI) in dogs and cats and to evaluate the applicability of a human classification system for TDI in dogs and cats. All patients diagnosed with a TDI were identified from the University of Wisconsin-Madison School of Veterinary Medicine Dentistry and Oral Surgery Service case log and the hospital patient processing software. The study population consisted of 621 dogs and cats, in a total of 660 patient visits from 2004 to 2012, admitted for oral treatment and subsequently diagnosed with at least one TDI Medical records including diagnostic imaging studies were reviewed to group the injury according to a classification system used in humans for TDI. Patient signalment, tooth injured, and number of injuries per patient were recorded and tabulated. The overall prevalence of TDI was 26.2%. The mean +/- SD number of TDI per patient was 1.45 +/- 0.85. All 14 classes of TDI recognized by the classification system utilized in humans were identified, and all (100%) TDI identified in this study were classifiable using this system. Enamel-dentin-pulp fracture was the most common TDI (49.6%). The most commonly injured teeth were the mandibular or maxillary canine teeth (35.5%). The most common age for dogs and cats with TDI were 3-6 years (33.0%) and 7-10 years (31.3%). With a frequency of 1 in 4 animals, TDI are common and represent a significant pet health concern. Most TDI are considered severe and require timely, and sometimes immediate, treatment. The adoption and utilization of a complete classification system, such as the one used in this study, is recommended in order to improve future epidemiological study of TDI in animals.

Longitudinal Evaluation of the Structural Integrity of Teeth Affected by Molar Incisor Hypomineralisation.

The aim of this prospective cohort study was to evaluate the risk of posteruptive breakdown and the development of caries lesions in teeth with molar incisor hypomineralisation (MIH). A total of 367 permanent incisors and first molars, affected and not affected by MIH lesions, of 45 children with MIH from Araraquara, São Paulo, Brazil, were evaluated at intervals from 6 to 12 months by assessing the severity of MIH, the presence of tooth caries lesions and the treatment needed. During the study period, all patients received preventive care. The data were analysed using Fisher's exact test and actuarial method survival analysis. Significant associations were also found in teeth between the presence of MIH and a DMFT index >0 in all periods and also between the need for treatment and the presence of MIH. The teeth affected by MIH opacities were healthy in 99% of incisors and 93% of molars at the end of the 12-month period. Due to the high likelihood of maintaining the tooth structure in opacities, the complete or premature removal of the affected area is not justified.

Time delays in treating dental trauma at a children's hospital and private pediatric dental practice.

PURPOSE: The purpose of this study was to compare the time interval between a child sustaining a dental injury and the rendering of treatment in a hospital setting and a private pediatric dental practice. METHODS: Data were collected from the patient records of children treated for dental trauma at a children's hospital emergency department, a children's hospital dental clinic, and a private pediatric dental practice. Data included demographics and the time, date, type of injury, and its treatment. RESULTS: Injuries were more severe, treatment was more complex, and the time interval between injury and treatment was longer for those children treated in the hospital setting versus private practice, regardless of distance traveled. Children treated at their dental home experienced fewer treatment delays. Insurance status, medical complexity, and associated injuries were not related to treatment delays. CONCLUSIONS: Children who seek emergency care for traumatic dental injuries in a hospital setting experience greater delays in treatment compared to those seeking care in a private practice setting. These findings might not be generalizable to other hospital settings or private practices due to the inherently unique characteristics of the sites used in this study.

Diagnosis and management of cemental tear: a case report.

A 32-year-old man complained of swelling after an extraction in the vicinity of the left maxillary premolars. The occlusal surface of the first premolar showed no caries while the second premolar was covered with a crown. Radiographic examination revealed a thin radiolucent defect subgingivally below the cementodentinal junction on the distal aspect. During a review of medical history, the patient presented an extracted fragment that was sent for histopathological examination. A root canal was performed and the defect was closed with mineral trioxide aggregate followed by glass ionomer cement. Histopathology revealed the fragment to be a cemental tear, a condition associated typically with old age, trauma, and traumatic occlusion. Dentists should be aware of this rare entity as a differential diagnosis in cases involving noncarious odontogenic pain.

Cast metal vs. glass fibre posts: a randomized controlled trial with up to 3 years of follow up.

OBJECTIVE: This randomized controlled trial compared the survival of glass fibre and cast metal dental posts used to restore endodontically treated teeth with no remaining coronal wall. METHODS: Fifty-four participants (45 women) and 72 teeth were evaluated during a follow-up period of up to 3 years. Teeth were randomly allocated to the glass-fibre and cast-metal post groups. All teeth were restored with single metal-ceramic crowns. Survival probabilities were analyzed using Kaplan-Meier statistics (p≤0.05). RESULTS: The 3-year recall rate was 92.3% and the survival rates of glass fibre and cast metal posts were similar (97.1% and 91.9%, respectively; p=0.682). Four failures were observed: two glass fibre posts in a premolar and anterior tooth debonded, one glass fibre post in a premolar debonded in association with root fracture, and one root fracture occurred in a molar with a cast metal post. CONCLUSIONS: Glass fibre and cast metal posts showed similar clinical performance in teeth with no remaining coronal wall after 3 years. CLINICAL SIGNIFICANCE: Posts are used to restore most endodontically treated teeth with no remaining coronal wall. This randomized controlled trial, one of few to compare glass fibre and cast metal posts in such teeth, showed that post type did not significantly influence the survival of restorations. These results can help dentists respond to the important question of how best to rehabilitate endodontically treated teeth with no remaining coronal wall.

Influence of cone beam CT enhancement filters on diagnosis ability of longitudinal root fractures.

OBJECTIVES: To determine whether cone beam CT (CBCT) enhancement filters influence the diagnosis of longitudinal root fractures. METHODS: 40 extracted human posterior teeth were endodontically prepared, and fractures with no separation of fragments were made in 20 teeth of this sample. The teeth were placed in a dry mandible and scanned using a Classic i-CAT® CBCT device (Imaging Sciences International, Inc., Hatfield, PA). Evaluations were performed with and without CBCT filters (Sharpen Mild, Sharpen Super Mild, S9, Sharpen, Sharpen 3 × 3, Angio Sharpen Medium 5 × 5, Angio Sharpen High 5 × 5 and Shadow 3 × 3) by three oral radiologists. Inter- and intraobserver agreement was calculated by the kappa test. Accuracy, sensitivity, specificity and positive and negative predictive values were determined. McNemar test was applied for agreement between all images vs the gold standard and original images vs images with filters (p < 0.05). RESULTS: Means of intraobserver agreement ranged from good to excellent. Angio Sharpen Medium 5 × 5 filter obtained the highest positive predictive value (80.0%) and specificity value (76.5%). Angio Sharpen High 5 × 5 filter obtained the highest sensitivity (78.9%) and accuracy (77.5%) value. Negative predictive value was the highest (82.9%) for S9 filter. The McNemar test showed no statistically significant differences between images with and without CBCT filters (p > 0.05). CONCLUSIONS: Although no statistical differences was observed in the diagnosis of root fractures when using filters, these filters seem to improve diagnostic capacity for longitudinal root fractures. Further in vitro studies with endodontic-treated teeth and research in vivo should be considered.

The influence of metallic posts in the detection of vertical root fractures using different imaging examinations.

OBJECTIVES: To assess the influence of metallic posts in the detection of simulated vertical root fractures (VRFs) using the following imaging examinations: 2 cone beam CT (CBCT) systems [CBCT1: NewTom(®) 3G (QR Srl, Verona, Italy) and CBCT2: i-CAT Next Generation(®) (Imaging Sciences International, Hatfield, PA)] and film and digital radiographs. Additionally, the influence of the orientation of the fracture line in the detection of VRFs was evaluated. METHODS: 100, human, single-rooted endodontically treated premolars were divided into 5 groups (Group 1: with posts and buccolingual VRFs, Group 2: with posts and mesiodistal VRFs, Group 3: without posts and with buccolingual VRFs, Group 4: without posts and with mesiodistal VRFs, and Group 5: with posts and without VRFs). The premolars were placed in human mandibles and imaged using the four examination modalities. The sensitivity and the specificity of each examination in the experimental groups were calculated. The data were analysed using Student's t-test. RESULTS: The presence of metallic posts reduced the sensitivity of the CBCT1 system (p = 0.0244). Digital radiographs and the CBCT1 and CBCT2 systems had a higher sensitivity in detecting buccolingual fractures in teeth with posts, whereas film and digital radiographs had a higher sensitivity in detecting buccolingual fractures in teeth without posts (p < 0.05). The CBCT1 examination demonstrated the lowest specificity (p < 0.05). CONCLUSIONS: The presence of metallic posts did not influence the sensitivity of most of the examinations, excluding the CBCT1 system. The fracture line orientation may influence VRF detection.

Taking the trauma out of trauma: an easy to follow guide for the management of trauma to the permanent dentition.

UNLABELLED: Treatment of dental trauma can be an infrequent, unpredictable and stressful experience for a dental practitioner. Correct diagnosis and management of such cases is of primary importance in the prognosis of the affected dentition. We have therefore constructed a number of easy to follow algorithms in management, both short and long term, for the range of traumatic injuries that can affect the permanent dentition. CLINICAL RELEVANCE: Immediate as well as longer term management of dental trauma cases can be difficult, therefore a clear treatment plan is of great importance in successful results.

Dental Trauma Guide: a source of evidence-based treatment guidelines for dental trauma.

Diagnosis and treatment for traumatic dental injuries are very complex owing to the multiple trauma entities represented by six luxation types and nine fracture types affecting both the primary and the permanent dentition. When it is further considered that fracture and luxation injuries are often combined, the result is that more than 100 trauma scenarios exist, when the two dentitions are combined. Each of these trauma scenarios has a specific treatment demand and prospect for healing. With such a complexity in diagnosis and treatment, it is obvious that even experienced practitioners may have problems in selecting proper treatment for some of these trauma types. To remedy this situation, an Internet-based knowledge base consisting of 4000 dental trauma cases with long-term follow up is now available to the public and the professions on the Internet using the address http://www.DentalTraumaGuide.org. It is the aspiration that the use of this Guide may lead the practitioner to offer an evidence-based diagnosis and treatment.

Longevity of repaired restorations: a practice based study.

UNLABELLED: The aim was to evaluate retrospectively the influence on restoration longevity of a repair and to evaluate longevity of repaired restorations. MATERIALS AND METHODS: In a practice, 1202 amalgam and 747 composite resin restorations were placed. 407 restorations failed (amalgam 293, composite 114), 246 restorations were repaired with composite resin using an etch-and-rinse technique. Of repaired restorations reason for failure and number of surfaces of original restoration, repair date, and date of patients' last visit were recorded. Whenever a new treatment was necessary, this was considered failure. Data were analysed by Kaplan-Meier statistics and log-rank tests (p<0.05). A multi-variate Cox-regression analysis was conducted on results for variables number of surfaces, repair reason, and repaired material. RESULTS: 133 amalgam restorations (57% due to fracture) and 113 composite restorations (62% due to caries) were repaired. 151 of 246 repaired restorations (61%) were still in service without further intervention after 4.8 years. The annual failure rates for repaired amalgam and composite restorations was 9.3% and 5.7% after 4 years (log-rank, p=0.001). Restorations that were repaired due to fracture had a lower survival than restorations that were repaired due to caries (log-rank, p=0.006). The Cox-regression showed influence of the gender but no significant influence of material or reason for repair, indicating that the findings are a consequence of joint negative influences of investigated variables. CONCLUSION: The present study shows that repairs can enhance the longevity of dental restorations considerably. Moreover, repairs on restorations failing due to caries have a better prognosis compared to repairs on restorations failing due to fracture.

Update on the management of dentoalveolar trauma.

PURPOSE OF REVIEW: Dentoalveolar injuries are the most common type of facial injury and are often associated with concomitant facial fractures. These injuries may initially be seen by surgeons who do not have formal dental training. This article reviews the assessment and management of dentoalveolar fractures. RECENT FINDINGS: Semi-flexible splinting of traumatized teeth for shorter periods of time than previously suggested is associated with better long-term outcomes. The use of dental implants to replace teeth lost to trauma is a predictable restorative option. SUMMARY: Surgeons need to be aware that dentoalveolar injuries may be a marker for other injuries. Prompt relocation and splinting of displaced teeth is associated with better outcomes.

Root fractures: the influence of type of healing and location of fracture on tooth survival rates - an analysis of 492 cases.

AIM: The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed. MATERIAL AND METHODS: Long-term survival rates were calculated using data from 492 root-fractured teeth in 432 patients. The cause of tooth loss was assessed as being the result of either pulp necrosis (including endodontic failures), new traumas or excessive mobility. The statistics used were Kaplan-Meier and the log rank method. RESULTS AND CONCLUSIONS: The location of the root fracture had a strong significant effect on tooth survival (P = 0.0001). The 10-year tooth survival of apical root fractures was 89% [95% confidence interval (CI), 78-99%], of mid-root fractures 78% (CI, 64-92%), of cervical-mid-root fractures 67% (CI, 50-85%), and of cervical fractures 33% (CI, 17-49%). The fracture-healing type offered further prognostic information. No tooth loss was observed in teeth with hard tissue fracture healing regardless of the position of the fracture. For teeth with interposition of connective tissue, the location of the fracture had a significant influence on tooth loss (P = 0.0001). For teeth with connective tissue healing, the estimated 8-year survival of apical, mid-root, and cervical-mid-root fractures were all more than 80%, whereas the estimated 8-year survival of cervical fractures was 25% (CI, 7-43%). For teeth with non-healing with interposition of granulation tissue, the location of the fracture showed a significant influence on tooth loss (P = 0.0001). The cause of tooth loss was found to be very dependent upon the location of the fracture. In conclusion, the long-term tooth survival of root fractures was strongly influenced by the type of healing and the location of the fracture.

Analysis of factors associated with cracked teeth.

INTRODUCTION: The purpose of this study was to analyze the characteristics, distribution, and associated factors of longitudinal fractured teeth according to the well-defined criteria of the American Association of Endodontists (AAE). METHODS: One hundred seven teeth with longitudinal fracture from 103 patients were diagnosed and analyzed. The patients' signs, symptoms, age, and sex were noted as well as the tooth number, dental arch, filling materials, size/classification of restoration, crack direction, pulp vitality, whether the patient had undergone endodontic treatment, bite test results, percussion test results, wear facet, and periodontal pocket depth. RESULTS: Eighty-seven teeth were diagnosed with a cracked tooth (81.3%), 14 were diagnosed with vertical root fracture (VRF, 13.1%), 4 had a split tooth (3.7%), and 2 had a fractured cusp (1.9%); 82.2% showed a sensitive reaction on the bite test. Longitudinal tooth fractures were observed most frequently in patient in their 40s. The upper first molar (28.0%) was most frequently cracked, followed by the lower first molar (25.2%), the lower second molar (20.6%), and the upper second molar (16.8%). Most longitudinal tooth fractures (72.0%) occurred mainly in restored teeth, whereas only 28.0% were found in intact teeth. Compared with resin (4.7%) or porcelain (0.9%), the use of nonbonded inlay restoration materials such as gold (20.5%) or amalgam (18.7%) increased the occurrence of longitudinal tooth fractures. Out of 107 of longitudinal fractured teeth, 33 (30.8%) were treated endodontically and 74 (69.2%) were not. VRF was associated with endodontic treatment. CONCLUSIONS: The bite test is most reliable for reproducing symptoms. The combined use of various examination methods is recommended for detecting cracks and minutely inspecting all directions of a tooth.

Tooth mobility changes subsequent to root fractures: a longitudinal clinical study of 44 permanent teeth.

The purpose of this study was to analyze tooth mobility changes in root-fractured permanent teeth and relate this to type of interfragment healing (hard tissue healing (HT), interfragment healing with periodontal ligament (PDL) and nonhealing with interposition of granulation tissue (GT) because of pulp necrosis in the coronal fragment. Furthermore, the effect of age, location of the fracture on the root, and observation period on mobility values was analyzed. Mobility values were measured for 44 of 95 previous reported root-fractured permanent incisors. Mobility changes were measured with a Mühlemanns periodontometer and noninjured incisors served as controls. The mobility values represented the labial-lingual excursion of the root measured in µm when the tooth received a frontal and a palatal impact of 100 g force. In 18 cases of hard tissue healing (HT), a slightly increased mobility was seen after 3 months and 1 year, and a normalization of mobility value was usually found after 5 and 10 years. In 17 cases of PDL healing, generally a higher mobility was found in comparison with root fractures healing with hard tissue, and a consistent decrease in mobility value was found in the course of the 10 year observation period. A tendency for reduced mobility over time was found, a relation that could possibly be explained by the known general decrease in tooth mobility with increasing age. Finally, nine cases of nonhealing with initial interposition of granulation tissue (GT) because of pulp necrosis in the coronal fragment resulted in increasing mobility values possibly related to a lateral breakdown of the PDL in relation to the fracture line. In control teeth, a lowering of mobility was found over the course of a 10-year observation period. In conclusion, mobility changes appeared to reflect the radiographic healing stages and known age effects upon tooth mobility.

Combination injuries 1. The risk of pulp necrosis in permanent teeth with concussion injuries and concomitant crown fractures.

BACKGROUND: The reported risk of pulp necrosis (PN) is low in teeth with concussion injuries. A concomitant crown fracture may affect the risk of PN. AIM: To analyze the influence of a crown fracture (with and without pulp exposure) on the risk of PN in teeth with concussion injury. MATERIAL: The study included 469 permanent incisors with concussion from 358 patients (226 male, 132 female). Among these, 292 had a concomitant crown fracture (70 with and 222 without pulp exposure). All teeth were examined and treated according to standardized protocol. STATISTICAL ANALYSIS: The risk of PN was analyzed by the Kaplan-Meier method and Cox regression. Risk factors included in the analysis: gender, age, stage of root development, type of crown fracture, and response to electric pulp test (EPT) at the initial examination. The level of significance was set at 5%. RESULTS: The risk of PN was low in teeth with immature root development [1.1%, 95% confidence intervals (CI): 0-3.4]. The following factors significantly increased the risk of PN in teeth with mature root development: crown fracture without pulp exposure [hazard ratio 4.1 (95% CI: 1.4-11.9), P = 0.01] and no response to EPT at the initial examination [hazard ratio 30.7 (95% CI: 7.7-121), P < 0.0001]. The overall risk of PN increased from 3.5% (95% CI: 0.2-6.8) to 11.0% (95% CI: 5.2-16.7) when a concomitant crown fracture without pulp exposure was present. If the tooth had both a crown fracture and gave no response to EPT, the risk further increased to 55.0% (95% CI: 34.3-75.8). CONCLUSION: No response to EPT at the initial examination or a concomitant crown fracture significantly increased the risk of PN in teeth with concussion injury and mature root development. If both risk factors were present there was a synergetic effect.

The effect of ferrule on the fracture mode of endodontically treated canines restored with fibre posts and metal-ceramic or all-ceramic crowns.

OBJECTIVES: The aim of this study was to evaluate the fracture mode of endodontically treated canines (ETC) restored with glass-fibre posts (GFP) and either metal-ceramic (MC) or all-ceramic (AC) crowns, in the presence or absence of 2 mm ferrule height. METHODS: Fifty recently extracted human maxillary canines were endodontically treated and randomly divided into 5 groups of 10 specimens each. Four groups (with or without ferrule) were restored with GFP, composite cores and either MC or AC crowns. The fifth group with intact ETC served as control. Teeth were loaded to fracture at a 135° angle to their long axis, at a cross-head speed 0.5 mm/min. The fracture modes were divided through optical microscopy to repairable and irreparable. Statistical analysis was performed by means of the Fisher's Exact test. RESULTS: All groups presented brittle fracture following bending deformation. Irreparable root fractures were the primary fracture mode independently of ferrule. The percentages (%) of repairable fractures were not statistically significant different amongst the MC and AC restored teeth independently of ferrule. However the 2 mm ferrule was associated to a higher percentage of repairable fractures, especially in teeth restored with AC crowns. CONCLUSIONS: The percentage (%) of repairable fractures was higher in all-ceramic compared to metal-ceramic ETC and in restorations with ferrule, although the differences were not statistically significant. CLINICAL SIGNIFICANCE: This in vitro study supports evidence that neither the type of crown restoration nor the presence of ferrule affects statistically significantly the mode of fracture of ETC restored with GFP.

Fracture resistance of root filled premolar teeth restored with direct composite resin with or without cusp coverage.

AIM: To evaluate the fracture resistance and fracture patterns of root filled maxillary first premolar teeth (with mesio-occlusal cavity preparation) restored with several composite restoration designs. METHODOLOGY: One hundred extracted sound human maxillary first premolars were randomly divided into five groups. Group 1 remained untreated (negative control). Conventional root canal treatment with additional mesial-occlusal cavity preparation was carried out on teeth in groups 2-5. In group 2, the teeth were restored intra-coronally with direct composite resin (positive control). In group 3, the palatal cusps of the teeth were reduced, and the cavities were restored with composite resin covering the palatal cusp (partial coverage). In group 4, the buccal and palatal cusps along with the distal marginal ridges were reduced; the cavities and cusps were restored with composite resin (conventional full coverage). In group 5, the buccal and palatal cusps were reduced but the distal marginal ridges were conserved. The cavities and the cusps were restored with composite resin (modified full coverage). All teeth were subjected to a progressive compressive loading parallel to their longitudinal axis until fracture. Fracture resistance was analysed using the one-way ANOVA and Fisher's LSD test. Fracture patterns were analyzed with chi-square test. The significance level was set at 0.05. RESULTS: The fracture resistance (mean ± SD) of groups 1-5 was 1131 ± 207N, 904 ± 184N, 927 ± 224N, 1095 ± 289N and 1085 ± 243N, respectively (groups 1, 4, 5 > groups 2, 3; P = 0.004). Cusp fractures were recorded as the fracture pattern in 20 (100%), 19 (95%), 16 (80%), 8 (40%) and 12 (60%) premolars in groups 1-5, respectively (groups 1, 2 > groups 4, 5; group 3 > group 4; P < 0.001). CONCLUSIONS: When direct composite resin was used to restore root filled maxillary first premolar teeth involving a proximal surface, those restored with full-coverage designs had greater fracture resistance.

Fracture susceptibility of endodontically treated teeth.

AIM: To assess the influence of cervical preparation on fracture susceptibility of roots. MATERIAL AND METHODS: During root canal instrumentation, the cervical portions were prepared with different taper instruments: I: no cervical preparation; II: #30/.08; III: #30/.10; IV: #70/.12. The specimens were sealed with the following filling materials (n = 8), A: unfilled; B: Endofill/gutta-percha; C: AH Plus/gutta-percha; D: Epiphany SE/Resilon. For the fracture resistance test, a universal testing machine was used at 1 mm per minute. RESULTS: anova demonstrated difference (P < 0.05) between taper instruments with a higher value for group I (205.3 ± 77.5 N) followed by II (185.2 ± 70.8 N), III (164.8 ± 48.9 N), and IV (156.7 ± 41.4 N). There was no difference (P > 0.05) between filling materials A (189.1 ± 66.3 N), B (186.3 ± 61.0 N), C (159.7 ± 69.9 N), and D (176.9 ± 55.2 N). CONCLUSIONS: Greater cervical wear using a #70/.12 file increased the root fracture susceptibility, and the tested filling materials were not able to restore resistance.