For the treatment of pulp calcification,dynamic navigation technology could assist in the establishment of pathways and avoid the occurrence of root canal complications such as lateral root canal perforation that might occur during free hand manipulation.This short paper reported a case of dynamic navigation assisted treatment of maxillary central incisor pulp calcification.The treatment were effective at 3,6 and 12 months after operation.

For the treatment of pulp calcification,dynamic navigation technology could assist in the establishment of pathways and avoid the occurrence of root canal complications such as lateral root canal perforation that might occur during free hand manipulation.This short paper reported a case of dynamic navigation assisted treatment of maxillary central incisor pulp calcification.The treatment were effective at 3,6 and 12 months after operation.

Craniocerebral injury with seawater immersion is a special kind of compound injury, with low temperature, high permeability, high alkali, high salt content, and bacterial infection being the main causes. The injury is also characterized with complex damage mechanisms, difficulty to treat, and poor prognosis. At present, the damage mechanisms of craniocerebral injury with seawater immersion are mainly studied by establishing the experimental animal models at the levels of tissue, cell, organelle, molecule, etc. However, the craniocerebral injury with seawater immersion is more complex than the simple onshore craniocerebral injury, therefore, a stable disease model is not easy to construct. Most researches on the specific injury mechanisms are relatively single and one-sided, with many different views in existence, and the damage mechanisms of craniocerebral injury with seawater immersion have hitherto not been clear. The authors reviewed the research progress in the damage mechanisms of craniocerebral injury with seawater immersion, in order to promote the in-depth study of the mechanism of craniocerebral injury with seawater immersion and provide reference for its clinical treatment.

Sex-determining region Y-related high-mobility group box 11(SOX11)was initially considered as one of the trans-acting factors supporting the differentiation of stem cells and the survival of neural precursors.However,in recent studies,it was found that SOX11 played an important role in the transcriptional regulation of the development,shaping and regeneration of neurons,and it was expected to be a target for the regeneration of injured nerves.This article reviews the physiological and pathophysiological functions of SOX11 in the central nervous system and its role in nerve regeneration.

Objective:To study the effects of the apical dentin surface morphology resected with Er∶YAG laser on the proliferation of human periodontal ligament cells(hPDLCs).Methods:66 single premolars were randomly divided into 3 groups(n=22),and the api-cal root slices were made by resection perpendicular to the root long axis 3 mm from the apex using high-speed handpiece(group A),piezosurgery(group B)and Er∶YAG laser(group C),respectively.SEM was used to observe the apical dentin surface in the aspects of debris,smear layer,dentinal tubules,cracks,ablation characteristics and the dentin surface roughness was measured.hPDLCs were clutured on the surface of the slices of the groups,CCK-8 method was used to detect cell proliferation on the samples at 24,48 and 72 h of culture,respectively.Results:The surface preparition time of group A was shorter than that of group B and C(P＜0.001).SEM observation showed that in group C,there was no residual debris or stained layer,and dentin tubule was visible on the dention sur-faces.Detritus and stained layers were observed in group A and B,and dentin tubule was not observed in group A.Cracks were observed in all the groups,but less in group C.Roughness(nm)of group C(1 487.13±295.90)was higher than that of group A and B(P＜0.001).CCK-8 assay showed that the cell proliferation(A value)of all groups increased gradually with the culture time after 24,48 and 72 h of hPDLCs seeded on the root surface.And the cell proliferation in group C was the most significant than that in group A and B(P＜0.05)at 48 and 72 h.Conclusion:The morphological performance of the apical dentin surface resected with Er∶YAG laser is more conducive to hPDLCs growth than that with the ultrasound and burs.

OBJECTIVE: We aimed to analyze the current indoor radon level and estimate the population risk of radon-induced lung cancer in urban areas of China. METHODS: Using the passive monitoring method, a new survey on indoor radon concentrations was conducted in 2,875 dwellings across 31 provincial capital cities in Chinese mainland from 2018 to 2023. The attributable risk of lung cancer induced by indoor radon exposure was estimated based on the risk assessment model. RESULTS: The arithmetic mean (AM) and geometric mean (GM) of indoor radon concentrations were 65 Bq/m³ and 55 Bq/m³, respectively, with 13.6% of measured dwellings exceeding 100 Bq/m³ and 0.6% exceeding 300 Bq/m³. The estimated number of lung cancer deaths induced by indoor radon exposure was 150,795, accounting for 20.30% (95% CI: 20.21%-20.49%) of the lung cancer death toll. CONCLUSION This study provided the most recent data on national indoor radon levels in urban areas and the attributable risk of lung cancer. These results served as an important foundation for further research on the disease burden of indoor radon exposure and radon mitigation efforts.
Radon/analysis* ; China/epidemiology* ; Air Pollution, Indoor/analysis* ; Lung Neoplasms/etiology* ; Humans ; Cities/epidemiology* ; Air Pollutants, Radioactive/adverse effects* ; Neoplasms, Radiation-Induced/etiology* ; Risk Assessment ; Radiation Monitoring

Posttraumatic stress disorder (PTSD), the most common mental illness after patients suffer physically or emotionally from traumatic events, can cause persistently strong, painful and terrible avoidance symptoms, emotional and cognitive changes, causing psychologically strong stimulation and heavy burden to patients and even leading to some extreme behavioral reactions. Traumatic brain injury (TBI) is an important factor in the occurrence of PTSD, both of which shares many similar pathological overlaps, and may coexist and interact with each other. The hippocampus and amygdala play a central role in the pathogenesis of PTSD, but the specific cellular and molecular and neural circuit mechanisms are still unclear. About two-thirds of the patients still meet the diagnostic criteria for PTSD after psychotherapy. However, the current treatment methods are complicated and not unified, and patients treated with medications may have adverse drug reactions, poor treatment outcomes and recurrence. Therefore, it is of great significance to further clarify the occurrence and development of PTSD in TBI patients. The authors reviewed the research progress of the pathogenesis and treatment of PTSD in TBI patients, so as to provide reference for the related research and treatment of PTSD in TBI patients.

Objective: To analyze effect of fractured file removal from the middle third root canal on root fracture resistance using finite element analysis, which provides a theoretical basis for clinical prognosis evaluation. Methods: Two finite-element models were established, the fractured file removal model (fractured file located in the middle third of root canals, followed by ultrasonic file removal and root canal preparation) and the control model (root canal preparation only), and compressive displacement dependencies on compressive force was computed and compared with experimental data for validation. The validated finite-element models were used to analyze the stress distribution differences during the initiation, propagation and completion of the crack between fractured file removal specimen and control one. Results: The critical breaking force of the fractured file removal specimen was 406 N, and the finite element simulation result was 396 N. The critical breaking force of the control specimen was 502 N, and the finite element simulation result was 483 N. The position of crack initiation in the finite element simulation was basically consistent with that in the experiment. The experimental data of compressive test and the results of finite-element computation were in agreement, thus validating the finite-element model. In the process of continuous pressure, the stress distribution of the control root is relatively uniform, and the location of crack initiation and the direction of propagation have a certain unpredictability. Compared with the control root, the stress concentration on the root with fracture file removal was obvious, especially on edges, and the number of cracks are much more. Because of the thinner radicular wall, the crack propagation rate is faster too. Therefore, the overall root fracture resistant is decreased obviously. Conclusions During the fractured file removal procedure, amount of dentine removed should be minimized, and the edges and corners which caused by fractured file removal should be shaped to smooth in order to reduce the stress concentration and prevent the root from fracture.

Objective: To investigate the association between the frequency and filling rate of lateral canals and the sealing quality in the apical third roots of the permanent teeth with failed endodontic treatments, so as to explore the failure factors of root canal therapy. Methods: Clinical records of the permanent teeth with failed endodontic treatments were collected from the Department of Endodontics, Capital Medical University School of Stomatology during a period of 2 years. The teeth were diagnosed as chronic apical periodontitis and then undergone endodontic microsurgery. The sealing quality of the apical root canal was observed by means of periapical radiographs. The surgical treatments were performed and the resected root apices were collected. The samples were scanned by micro-computed tomography and the 3D volume rendered images of the resected root apices were reconstructed. Moreover, the frequency and the filling rate of lateral canals in the apical third roots were calculated. The potential relationship between tooth position and the presence of lateral canals was evaluated. Results: Totally 89 teeth with 89 root apices met the inclusion criteria and were included in the present study. The rate of correct-filling, underfilling and overfilling was 40% (36/89), 32% (28/89), and 28% (25/89), respectively, examined by periapical radiographs. Amongst all of the 89 samples, lateral canals were found in 44 samples. The incidence of apices with lateral canals was 49% (44/89). Furthermore, 3 out of 44 samples were fully filled with material in the lateral canals, and the rest 41 samples showed no filling materials. The filling rate of the lateral canals was 7% (3/44). However, no significant difference was detected between the tooth position and the presence of lateral canals (P>0.05). Conclusions The sealing quality of the apical third roots in permanent teeth with failed endodontic treatments was not good enough. The incidence of apices with lateral canals was high, but the filling rate of the canals was low. Further studies are needed to explore the relationship between lateral canals and the failure of endodontic treatment.