Instrument separation is a critical complication during root canal therapy, impacting treatment success and long-term tooth preservation. The etiology of instrument separation is multifactorial, involving the intricate anatomy of the root canal system, instrument-related factors, and instrumentation techniques. Instrument separation can hinder thorough cleaning, shaping, and obturation of the root canal, posing challenges to successful treatment outcomes. Although retrieval of separated instrument is often feasible, it carries risks including perforation, excessive removal of tooth structure and root fractures. Effective management of separated instruments requires a comprehensive understanding of the contributing factors, meticulous preoperative assessment, and precise evaluation of the retrieval difficulty. The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes. The current manuscript provides a framework for understanding the causes, risk factors, and clinical management principles of instrument separation. By integrating effective strategies, endodontists can enhance decision-making, improve endodontic treatment success and ensure the preservation of natural dentition.
Humans ; Root Canal Therapy/adverse effects* ; Consensus ; Root Canal Preparation/adverse effects*

Objective:To investigate the regulatory effects of transcutaneous auricular vagus nerve stimulation (taVNS) on functional connectivity (FC) of thalamic subregions in patients with premenstrual syndrome (PMS).Methods:This study was a cross-sectional investigation. Clinical, laboratory, and imaging data were retrospectively collected from 56 PMS patients (PMS group) and 66 healthy controls (control group) recruited from various universities and hospitals in Nanning between November 2021 and June 2024. Resting-state functional MRI (fMRI) data and fMRI data during taVNS immediate stimulation (2 Hz, 25 Hz) were acquired from subjects during their late luteal phase. Using thalamic subregions (anterior thalamic nucleus, lateral nucleus, ventral nucleus, medial nucleus, central nucleus, posterior nucleus) as seeds, two-sample t-tests or paired t-tests were employed to analyze alterations in thalamic subregion FC in PMS patients and the regulatory effects of taVNS on these changes. Independent samples t-test were used to compare the differences in clinical and laboratory indicators between the PMS group and the control group. The relationship between taVNS regulation of thalamic subregion FC in PMS patients and thalamic internal functional connectivity were analyzed using mediation effect analysis. Results:Compared to the control group, patients in the PMS group showed increased scores on the Daily Record of Severity of Problems, Pittsburgh Sleep Quality Index, Self-Rating Anxiety Scale, Self-Rating Depression Scale, Hamilton Anxiety Rating Scale 17, and Hamilton Depression Rating Scale 14 during the late luteal phase ( P<0.05). At baseline, PMS patients exhibited higher FC between the left thalamic lateral nucleus and the left insula, and lower FC between the left medial nucleus, posterior nucleus, and ventral nucleus of the thalamus and the right middle frontal gyrus (MFG) compared to the control group (GRF corrected, voxel-level P<0.001, cluster-level P<0.05). During 2 Hz taVNS immediate stimulation in PMS group, FC between the left thalamic medial nucleus, posterior nucleus, ventral nucleus and the right MFG, as well as the FC between the left thalamic ventral nucleu and the left MFG increased compared to baseline levels; meanwhile, FC between the left thalamic posterior nucleus, ventral nucleus and the left insula decreased compared to baseline levels (GRF corrected, voxel-level P<0.001, cluster-level P<0.05). During 25 Hz taVNS immediate stimulation, the FC between the left thalamic ventral nucleus and the right MFG decreased compared to the baseline level (GRF corrected, voxel-level P<0.001, cluster-level P<0.05). Mediation effect analysis showed that the FC between the left thalamic posterior nucleus and the left lateral nucleus mediated part of the association between the FC of the left lateral thalamic nucleus-left insula and the FC of the left ventral thalamic nucleus-left putamen/insula; there were significant direct effects between the FC of the left lateral thalamic nucleus-the left posterior nucleus and FC of the left lateral thalamic nucleus-the left insula, as well as between the FC of the left ventral thalamic nucleus-the left MFG and FC of the left ventral thalamic nucleus-the right MFG. Conclusions:taVNS can modulate abnormal FC of the left thalamic subregions in PMS patients, restoring it toward normalization. The regulatory effects of 2 Hz stimulation are more pronounced than those of 25 Hz stimulation. This modulation primarily operates through two pathways: the left thalamic lateral nucleus-left insula-left thalamic ventral nucleus pathway and the left MFG-left thalamic ventral nucleus-right MFG.

Objective:To investigate the effects of repetitive transcranial magnetic stimulation(rTMS) on learning memory and abnormal Aβ deposition in cerebral amyloid angiopathy(CAA) model mice, and further to investigate whether the mechanism involves the transport function of glymphatic system.Methods:Eight-month-old SPF grade Tg-SWDI mice were randomly divided into the CAA group and the rTMS group according to the random number table method with 7 in each group.Seven wild-type mice of the same genetic background and age served as the control group. The mice in rTMS group received two weeks of high-frequency rTMS intervention, and the mice in CAA group and control group were only restrained without rTMS intervention.Learning and memory functions were evaluated using the Morris water maze test.Amyloid-beta deposition, glymphatic system clearance, and aquaporin-4(AQP4) polarization were assessed using immunofluorescence, and AQP4 expression levels were measured by Western blot.Statistical analysis of the data was conducted using SPSS 25.0 and GraphPad Prism 9.5 softwares.Repeated-measures ANOVA was used for data on escape latency, and one-way ANOVA was used for comparisons between multiple groups for other data.Results:(1)In the novel object recognition test, there were statistically significant differences in recognition indices among the three groups of mice ( F=22.59, P<0.05). Compared with the control group, the mice in the CAA group showed a significant decrease in the new object recognition index ( P<0.05).Compared with the CAA group, the mice in the rTMS group showed a significant increase in the new object recognition index ( P<0.05).(2)In the Y-maze, there were statistical differences in the spontaneous alternation rates among the three groups ( F=5.00, P<0.05). Compared with the control group, the spontaneous alternation rate in the CAA group was significantly lower ( P<0.05).And compared with the CAA group, the spontaneous alternation rate in the rTMS group was significantly higher ( P<0.05).(3)In the Morris water maze test, there were significant interactions in escape latency among the three groups ( F=4.05, P=0.02), significant main effects of time ( F=713.22, P<0.01), and significant main effects of group ( F=421.55, P<0.01). There was no significant statistical difference in swimming speed among the three groups ( F=0.19, P>0.05), while the difference of the number of entries into the inner zone and the proportion of time spent were statistically significant( F=71.67, 294.14, both P<0.05).Compared with the control group, the CAA group mice significantly decreased in the number of entries into the inner zone and the proportion of time spent in the middle zone (both P<0.01).(4)Compared with the CAA group, the rTMS group significantly increased in the number of entries into the inner zone and the proportion of time spent in the middle zone (both P<0.01).The result of immunofluorescence test showed that there was a statistically significant difference in the levels of Aβ in the cerebral vessels among the three groups( F=385.76, P<0.01).The levels of Aβ in the cerebral vessels of the CAA group (62.00±2.65) were significantly higher than those in the control group (9.00±1.00, P<0.01).The levels in the rTMS group (51.33±3.21) were significantly lower than those in the CAA group (62.00±2.65, P<0.01). Using the residual fluorescence tracer levels of the control group as a baseline, there were statistically significant differences in the tracer intensities in the corpus callosum and cerebral cortex( F=258.97, 46.44, both P<0.05), the tracer intensities in the corpus callosum (3.57±0.21) and cerebral cortex (4.96±0.79) of the CAA group mice were significantly higher than those in the rTMS group (1.45±0.14, 1.78±0.47, P<0.01). The polarization of AQP4 in the cerebral cortex of rTMS group (0.51±0.07) was significantly higher than that in the CAA group (0.30±0.02, P<0.01). Conclusion:rTMS can alleviate learning memory and abnormal Aβ deposition in CAA model mice by modulating AQP4 polarisation and promoting transport function of glymphatic system.

Objective To explore the impact factors of misjudge of pneumoconiosis stage based on GBZ70-2015 criteria.Methods Sixty-five case of pneumoconiosis were retrospectively enrolled.Chest high-resolution CT were independently analyzed by one associate chief physician,one attending physician and one resident physician,respectively.The stage of pneumoconiosis was judged,and the inter-observer consistency was observed.Taken the results of 5 experts using Delphi method as gold standard,the impact factors of misjudge of pneumoconiosis stage were analyzed.Results Among 65 cases,there were 42 cases of stage 1,16 cases of stage 2 and 7 cases of stage 3 pneumoconiosis.The inter-observer consistency of pneumoconiosis stage was relatively high(Kappa=0.653),of stage 3 pneumoconiosis was the best(Kappa=0.803),followed by stage 1(Kappa=0.661),while of stage 2 was the lowest(Kappa=0.518).Radiologist lack experience(OR=4.872),the lesions mainly located in the posterior upper area of lungs(OR=2.317),the present of r-type small shadows(OR=3.105)and high CT pulmonary emphysema index(OR=1.214)were all independent impact factors of misjudge of pneumoconiosis stage(all P＜0.05).Conclusion Both the experience of radiologist and lesions'heterogeneity were main impact factors of misjudge of pneumoconiosis stage based on GBZ70-2015 criteria.

Objective Analyzing the impact of malignant tumors on the life expectancy of urban residents of different ages and genders.Methods Applying the Fulfillment Index proposed by Prithwis Das Gupta,analyze the 2020 national urban resident mortalitysurveillance data by age and gender using Excel software.Results In 2020,the lifeexpectancy at birth for the urban population was 81.21 years(78.80 years for males and 83.80 years for females).The loss of life expectancy due to malignant tumors was 2.90 years(3.33 years for males and 2.32 years for females).The majority of deaths from malignant tumors were concentrated in the 40~60 age group,and the impact on potential life expectancy increased with age.The 60－ age group experienced the highest loss of potential life expectancy due to malignant tumors.There were differences in the Fulfillment Index between males and females.The highest Fulfillment Index for males was in the 60－ age group(40.68),while for females,it was in the 40－ age group(47.85).In age groups below 60,the Fulfillment Index for females was consistently higher than that for males,indicating a trend of malignant tumors occurring at a younger age in females.Conclusion The loss of life expectancy due to malignant tumors varies across different age groups and genders,highlighting the need for different prevention and treatment priorities.Health authorities should guide and enhance public awareness of malignant tumor prevention to help extend life expectancy.

Objective:To investigate the effects of repetitive transcranial magnetic stimulation(rTMS) on learning memory and abnormal Aβ deposition in cerebral amyloid angiopathy(CAA) model mice, and further to investigate whether the mechanism involves the transport function of glymphatic system.Methods:Eight-month-old SPF grade Tg-SWDI mice were randomly divided into the CAA group and the rTMS group according to the random number table method with 7 in each group.Seven wild-type mice of the same genetic background and age served as the control group. The mice in rTMS group received two weeks of high-frequency rTMS intervention, and the mice in CAA group and control group were only restrained without rTMS intervention.Learning and memory functions were evaluated using the Morris water maze test.Amyloid-beta deposition, glymphatic system clearance, and aquaporin-4(AQP4) polarization were assessed using immunofluorescence, and AQP4 expression levels were measured by Western blot.Statistical analysis of the data was conducted using SPSS 25.0 and GraphPad Prism 9.5 softwares.Repeated-measures ANOVA was used for data on escape latency, and one-way ANOVA was used for comparisons between multiple groups for other data.Results:(1)In the novel object recognition test, there were statistically significant differences in recognition indices among the three groups of mice ( F=22.59, P<0.05). Compared with the control group, the mice in the CAA group showed a significant decrease in the new object recognition index ( P<0.05).Compared with the CAA group, the mice in the rTMS group showed a significant increase in the new object recognition index ( P<0.05).(2)In the Y-maze, there were statistical differences in the spontaneous alternation rates among the three groups ( F=5.00, P<0.05). Compared with the control group, the spontaneous alternation rate in the CAA group was significantly lower ( P<0.05).And compared with the CAA group, the spontaneous alternation rate in the rTMS group was significantly higher ( P<0.05).(3)In the Morris water maze test, there were significant interactions in escape latency among the three groups ( F=4.05, P=0.02), significant main effects of time ( F=713.22, P<0.01), and significant main effects of group ( F=421.55, P<0.01). There was no significant statistical difference in swimming speed among the three groups ( F=0.19, P>0.05), while the difference of the number of entries into the inner zone and the proportion of time spent were statistically significant( F=71.67, 294.14, both P<0.05).Compared with the control group, the CAA group mice significantly decreased in the number of entries into the inner zone and the proportion of time spent in the middle zone (both P<0.01).(4)Compared with the CAA group, the rTMS group significantly increased in the number of entries into the inner zone and the proportion of time spent in the middle zone (both P<0.01).The result of immunofluorescence test showed that there was a statistically significant difference in the levels of Aβ in the cerebral vessels among the three groups( F=385.76, P<0.01).The levels of Aβ in the cerebral vessels of the CAA group (62.00±2.65) were significantly higher than those in the control group (9.00±1.00, P<0.01).The levels in the rTMS group (51.33±3.21) were significantly lower than those in the CAA group (62.00±2.65, P<0.01). Using the residual fluorescence tracer levels of the control group as a baseline, there were statistically significant differences in the tracer intensities in the corpus callosum and cerebral cortex( F=258.97, 46.44, both P<0.05), the tracer intensities in the corpus callosum (3.57±0.21) and cerebral cortex (4.96±0.79) of the CAA group mice were significantly higher than those in the rTMS group (1.45±0.14, 1.78±0.47, P<0.01). The polarization of AQP4 in the cerebral cortex of rTMS group (0.51±0.07) was significantly higher than that in the CAA group (0.30±0.02, P<0.01). Conclusion:rTMS can alleviate learning memory and abnormal Aβ deposition in CAA model mice by modulating AQP4 polarisation and promoting transport function of glymphatic system.

Objective Analyzing the impact of malignant tumors on the life expectancy of urban residents of different ages and genders.Methods Applying the Fulfillment Index proposed by Prithwis Das Gupta,analyze the 2020 national urban resident mortalitysurveillance data by age and gender using Excel software.Results In 2020,the lifeexpectancy at birth for the urban population was 81.21 years(78.80 years for males and 83.80 years for females).The loss of life expectancy due to malignant tumors was 2.90 years(3.33 years for males and 2.32 years for females).The majority of deaths from malignant tumors were concentrated in the 40~60 age group,and the impact on potential life expectancy increased with age.The 60－ age group experienced the highest loss of potential life expectancy due to malignant tumors.There were differences in the Fulfillment Index between males and females.The highest Fulfillment Index for males was in the 60－ age group(40.68),while for females,it was in the 40－ age group(47.85).In age groups below 60,the Fulfillment Index for females was consistently higher than that for males,indicating a trend of malignant tumors occurring at a younger age in females.Conclusion The loss of life expectancy due to malignant tumors varies across different age groups and genders,highlighting the need for different prevention and treatment priorities.Health authorities should guide and enhance public awareness of malignant tumor prevention to help extend life expectancy.

Objective To explore the impact factors of misjudge of pneumoconiosis stage based on GBZ70-2015 criteria.Methods Sixty-five case of pneumoconiosis were retrospectively enrolled.Chest high-resolution CT were independently analyzed by one associate chief physician,one attending physician and one resident physician,respectively.The stage of pneumoconiosis was judged,and the inter-observer consistency was observed.Taken the results of 5 experts using Delphi method as gold standard,the impact factors of misjudge of pneumoconiosis stage were analyzed.Results Among 65 cases,there were 42 cases of stage 1,16 cases of stage 2 and 7 cases of stage 3 pneumoconiosis.The inter-observer consistency of pneumoconiosis stage was relatively high(Kappa=0.653),of stage 3 pneumoconiosis was the best(Kappa=0.803),followed by stage 1(Kappa=0.661),while of stage 2 was the lowest(Kappa=0.518).Radiologist lack experience(OR=4.872),the lesions mainly located in the posterior upper area of lungs(OR=2.317),the present of r-type small shadows(OR=3.105)and high CT pulmonary emphysema index(OR=1.214)were all independent impact factors of misjudge of pneumoconiosis stage(all P＜0.05).Conclusion Both the experience of radiologist and lesions'heterogeneity were main impact factors of misjudge of pneumoconiosis stage based on GBZ70-2015 criteria.

Objective:To investigate the regulatory effects of transcutaneous auricular vagus nerve stimulation (taVNS) on functional connectivity (FC) of thalamic subregions in patients with premenstrual syndrome (PMS).Methods:This study was a cross-sectional investigation. Clinical, laboratory, and imaging data were retrospectively collected from 56 PMS patients (PMS group) and 66 healthy controls (control group) recruited from various universities and hospitals in Nanning between November 2021 and June 2024. Resting-state functional MRI (fMRI) data and fMRI data during taVNS immediate stimulation (2 Hz, 25 Hz) were acquired from subjects during their late luteal phase. Using thalamic subregions (anterior thalamic nucleus, lateral nucleus, ventral nucleus, medial nucleus, central nucleus, posterior nucleus) as seeds, two-sample t-tests or paired t-tests were employed to analyze alterations in thalamic subregion FC in PMS patients and the regulatory effects of taVNS on these changes. Independent samples t-test were used to compare the differences in clinical and laboratory indicators between the PMS group and the control group. The relationship between taVNS regulation of thalamic subregion FC in PMS patients and thalamic internal functional connectivity were analyzed using mediation effect analysis. Results:Compared to the control group, patients in the PMS group showed increased scores on the Daily Record of Severity of Problems, Pittsburgh Sleep Quality Index, Self-Rating Anxiety Scale, Self-Rating Depression Scale, Hamilton Anxiety Rating Scale 17, and Hamilton Depression Rating Scale 14 during the late luteal phase ( P<0.05). At baseline, PMS patients exhibited higher FC between the left thalamic lateral nucleus and the left insula, and lower FC between the left medial nucleus, posterior nucleus, and ventral nucleus of the thalamus and the right middle frontal gyrus (MFG) compared to the control group (GRF corrected, voxel-level P<0.001, cluster-level P<0.05). During 2 Hz taVNS immediate stimulation in PMS group, FC between the left thalamic medial nucleus, posterior nucleus, ventral nucleus and the right MFG, as well as the FC between the left thalamic ventral nucleu and the left MFG increased compared to baseline levels; meanwhile, FC between the left thalamic posterior nucleus, ventral nucleus and the left insula decreased compared to baseline levels (GRF corrected, voxel-level P<0.001, cluster-level P<0.05). During 25 Hz taVNS immediate stimulation, the FC between the left thalamic ventral nucleus and the right MFG decreased compared to the baseline level (GRF corrected, voxel-level P<0.001, cluster-level P<0.05). Mediation effect analysis showed that the FC between the left thalamic posterior nucleus and the left lateral nucleus mediated part of the association between the FC of the left lateral thalamic nucleus-left insula and the FC of the left ventral thalamic nucleus-left putamen/insula; there were significant direct effects between the FC of the left lateral thalamic nucleus-the left posterior nucleus and FC of the left lateral thalamic nucleus-the left insula, as well as between the FC of the left ventral thalamic nucleus-the left MFG and FC of the left ventral thalamic nucleus-the right MFG. Conclusions:taVNS can modulate abnormal FC of the left thalamic subregions in PMS patients, restoring it toward normalization. The regulatory effects of 2 Hz stimulation are more pronounced than those of 25 Hz stimulation. This modulation primarily operates through two pathways: the left thalamic lateral nucleus-left insula-left thalamic ventral nucleus pathway and the left MFG-left thalamic ventral nucleus-right MFG.

Objective To compare the detection rate of right hemicolonic polyp between indigo carmine staining and white light endoscopy.Methods A total of 1052 patients with colonoscopic examination in Qing-baijiang District People's Hospital of Chengdu City from July 2022 to March 2023 were selected as the study subjects and divided into the indigo carmine staining group and white light endoscopy group,526 cases in each group.The right hemicolon was observed by indigo carmine staining and white light pattern respectively.The difference in the detection rate of right hemicolonic polyp was compared between the two detection methods. Results Compared with the white light endoscopic examination group,the detection rate of the right hemico-lonic polyp (41.6％),detection rate of the right hemicolon adenoma (20.9％),detection rate of wide basal ser-rated lesion (2.1％),detection rate of proliferative polyps (20.3％),detection rate of Paris type 0-Ⅱ (38.0％),detection rate of NICE 1 type (pale lesion,22.2％),detection rate of polyps with a diameter<5 mm (30.5％) and the consistency rate of pathological biopsy (86.4％),specificity (84.7％) and sensitivity (88.2％) in the indigo carmine staining group were higher,and the differences were statistically significant (P<0.05).There was no statistical difference in the duration of mirror withdrawal between the white light endoscopy group and the indigo carmine staining group (t=1.407,P=0.160).Conclusion The endoscopic examination with indigo carmine staining has a higher detection rate for right hemicolonic polyp,and is easier to detect micropolyps and flat polyps with pale color.