OBJEVTIVETo evaluate the effect of different restoration methods on fracture resistance of endodontically treated teeth.

METHODSFifty intact extracted maxillary first premolars were randomly divided into 5 groups. Medial-occlusal cavity models were established in all the test groups (B-E) according to the same standard, followed by treatments with defect exposure only, defect filling with light cured composite resin, indirect resin inlays, or light cured composite resin combined with Biosplint fiber. Each specimen was tested using a universal test machine at 1.00 mm/min until fracture and the fracture load was recorded. The load angle was 45 degree to the long axis of the teeth, and the load was pointed to the middle of the lingual surface on the buccal cusp. The fracture resistance was analyzed statistically.

RESULTSThe mean load to cause fracture of the samples in each group group A to E was 1.27∓0.41, 0.23∓0.17, 0.55∓0.31, 0.89∓0.40, and 0.98∓0.34 kN, respectively, showing significant differences between the groups.

CONCLUSIONThe fracture resistance of the teeth is reduced after endodontic therapy, but can be increased significantly by restoration with composite resin inlay or light cured composite resin combined with Biosplint fiber.

Bicuspid ; physiopathology ; Composite Resins ; chemistry ; Dental Materials ; chemistry ; Dental Restoration, Permanent ; methods ; Dental Stress Analysis ; Humans ; Inlays ; Maxilla ; Tooth Fractures ; physiopathology ; Tooth, Nonvital ; physiopathology ; therapy

Objective:To explore the application value of scenario simulation teaching combined with two-way evaluation in standardized training of pediatric nursing.Methods:A total of 34 trainees who received standardized training of pediatric nursing in The First Affiliated Hospital of Air Force Medical University from March 2018 to March 2019 were selected as the control group, and another 42 trainees from April 2019 to July 2020 were selected as the study group. The control group used traditional teaching, and the study group used scenario simulation teaching combined with two-way evaluation. Theoretical examination and scenario simulation exercise examination were used to assess the theoretical knowledge and clinical practice ability of the trainees, and questionnaire survey was used to evaluate the satisfaction of the trainees with the teaching effect. SPSS 22.0 was used for t-test. Results:The scores of theoretical examination[(95.12±6.24) vs. (91.05±5.12)] and scenario simulation exercise examination (nursing practice skill operation ability, ability to combine theory and practice, clinical thinking and judgment ability, emergency handling ability, communication ability, humanistic care and professional learning ability, and work attitude) of the trainees in the study group were higher than those in the control group, and the differences were statistically significant ( P<0.05). The satisfaction evaluation of the trainees in the study group with the teaching effect was higher than that in the control group, and the difference was statistically significant ( P<0.001). Conclusion:Scenario simulation teaching combined with two-way evaluation can improve the theoretical knowledge, clinical practice ability, and teaching satisfaction of pediatric nursing trainees.

Objective To observe the clinical efficacy of radiofrequency ablation for treatment of discogenic lumbar spinal nerve posterior branch neuralgia after vertebral column endoscope operation. Methods Thirty-six patients with discogenic lumbar spinal nerve posterior branch neuralgia after vertebral column endoscope surgery admitted to the Affiliated Hospital of Logistics University of People's Armed Police from December 2011 to December 2017 were enrolled. According to difference in therapeutic methods, they were randomly divided into two groups, 18 cases in each group. The radiofrequency ablation group was treated with X-ray imaging guided lumbar spinal nerve posterior branch radiofrequency thermo-coagulation; the drug group received oral diclofenac sodium conservative treatment, 75 mg twice daily for 3 weeks. Both groups were followed up for 6 months, visual analogue scores (VAS) were used to evaluate the pain before and after treatment, the Oswestry dysfunction index was used to assess the degree of lumbar function recovery, and the surgical complications and adverse drug reactions were observed. Results The VAS scores in the two groups were similar before treatment; after treatment for 1 month, the VAS scores in both groups were significantly lower than those before treatment (radiofrequency ablation group: 1.83±0.71 vs. 5.67±0.77; drug group: 2.22±0.43 vs. 5.28±0.67, both P < 0.05); after treatment for 3 months and 6 months, the VAS scores were increased gradually, however, the scores of radiofrequency ablation group were significantly lower than those in the drug group (3 months was 2.00±0.59 vs. 3.39±0.70, 6 months was 2.17±0.51 vs. 3.61±0.50, both P < 0.05), moreover, the excellent and good rates of postoperative pain efficacy and of Oswestry dysfunction index improvement in the radiofrequency ablation group were significantly higher than those in the drug group [excellent and good rates of postoperative pain efficacy: 94.44% (17/18) vs. 22.22% (4/18), excellent and good rates of Oswestry dysfunction index improvement: 77.78% (14/18) vs. 44.44% (8/18), both P < 0.05]. There were no complications of infection and spinal nerve anterior branch injury in the radiofrequency ablation group, and 6 patients in the drug group presented mild gastric discomfort, which was relieved after symptomatic treatment. Conclusion The radiofrequency ablation is an effective method for treatment of discogenic lumbar neuralgia after vertebral column operation, compared with the conservative therapy, the ablation is more effective to relieve pain for a long time, promote the recovery of neural function, and the operation is safe with very few adverse reactions.

Objective:To investigate the value of serum miR-143 level combined with MRI in predicting the early response to concurrent chemoradiotherapy (CCRT) in cervical cancer.Methods:A total of 85 patients with pathologically confirmed cervical cancer underwent conventional MRI, intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI), and dynamic contrast-enhanced MRI (DCE-MRI) before CCRT. The biopsy tissues and serum samples were collected. The differential expression of miRNA in the biopsy tissues was determined by microarray chip. The expression level of miR-143 in the serum samples was analyzed by qRT-PCR. All patients were divided into the non-residual and residual tumor groups according to post-treatment MRI. Pre-treatment clinical factors, MRI parameters and miR-143 between two groups were statistically analyzed by the univariate and multivariate analyses. The optimal thresholds and predictive performance for post-treatment incidence of residual tumors were estimated by drawing the ROC curve.Results:At one month after CCRT, there were 52 patients in the non-residual tumor group and 33 patients in the residual tumor group. In the residual tumor group, pre-treatment FIGO staging, apparent diffusion coefficient (ADC), D and V e were significantly higher (all P<0.05), whereas K trans value was significantly lower ( P<0.001) when compared to those in the non-residual tumor group. The miRNA array analysis showed that there were 16 miRNAs with differential expression levels between two groups (all P<0.05). Among them, the increase of miR-143 was the most significant in the residual tumor group. Compared with the residual tumor group, the expression level of serum miR-143 was significantly down-regulated in the non-residual tumor group ( P=0.002). Compared with the SiHa cells, the expression level of miR-143 in the SiHa-R cells was significantly up-regulated ( P<0.05). Multivariate analysis showed that only miR-143, D, K trans and V e were the independent prognostic factors. The combination of multi-parametric MRI and miR-143 exhibited the highest predictive performance (AUC=0.975), with a sensitivity of 84.8% and a specificity of 96.2%. Conclusion:The combination of multi-parametric MRI with miR-143 further improves the predictive performance for residual tumors after CCRT, which contributes to the personalized treatment of cervical cancer.