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Using digital technologies in concurrently performing missing tooth implantation and preparation of remaining teeth is a solution to reduce the number of visits and improve efficiency. This paper proposes a digital process for simultaneously implanting and preparing teeth. It integrates implant surgical guide and 3D-printed tooth preparation guide into a single guide and completes guided implant placement and precise tooth preparation. Based on "repair-oriented" virtual implant planning, the implant surgical guide can improve the efficiency and predictability of implant placement, and its linear accuracy is about 1 mm. The tooth preparation guide precisely guides tooth preparation and restoration space visualization, ensuring the quality of the tooth preparation. The two guides have different design accuracy requirements, and thus their combination improves the overall guiding accuracy requirements. The concurrent application of the two guides minimizes the clinical operation time, number of visits, and economic burden of patients.
Subject(s)
Humans , Surgery, Computer-Assisted , Dental Implantation, Endosseous , Printing, Three-Dimensional , Technology , Tooth Preparation , Computer-Aided Design , Dental Implants , Imaging, Three-Dimensional , Cone-Beam Computed TomographyABSTRACT
Objective To investigate the actual situation and problems faced by radiological professionals in implementing The Specification of Radiological Protection Assessment for Occupational Hazard in Construction Project Part 2: Radiotherapy Facility (GBZ/T 220.2—2009). Methods A questionnaire survey was performed on radiological professionals who were selected, using the multi-stage stratified sampling method, from those who had participated in the assessment for occupational hazard in the construction project of radiotherapy facility from seven provinces and cities in China. A descriptive statistical analysis was used to analyze the general information and the awareness, promotion, and implementation of the standard of the participants. The chi-squared test was used to compare the data of different regions. Results A total of 173 radiological professionals from seven provinces and cities were investigated. They had a relatively high awareness rate (98.8%) of the standard, but a relatively low training and promotion rate (65.3%) of the standard. There were no significant differences in the awareness rate and the training and promotion rate between different regions (χ2 = 2.743, P = 0.602; χ2 = 5.584, P = 0.061). The use frequency of the standard was relatively low among the radiological professionals, and 64.9% of them thought that it was necessary to revise the standard, especially to further refine the scope of application, key technical indicators such as assessment methods, and radiological protection management regulations. Conclusion The training and promotion of the standard should be strengthened among radiological professionals. Some key technical indicators in the standard should be clarified and refined.
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Objective To assess the frequency of medical exposure from X-ray diagnostic equipment in Tianjin,and provide recommendations for regulating medical radiation management and rational allocation and use of medical and health resources.Methods Using the census method,questionnaries were issued in the form of an administrative document to investigate the basic information on X-ray diagnostic equipment and medical procedure frequency in 687 hospitals (excluding military and armed police hospitals) in 2018.Mean values of frequencies were derived by dividing the number of procedures for each type of X-ray equipment by the total number of permanent residents.Results There were 1 562 pieces of X-ray diagnostic equipment (including interventional radiology),with an average of 1.00 unit per 10 000 population.There were 4 782 radiation workers engaged with X-ray diagnostic work (including interventional radiology),averaged on 3.06 workers per unit,with the highest of 5.25 workers per unit in tertiary hospitals and the lowest of 1.18 in ungraded hospitals.The city's X-ray diagnostic medical exposure came from 8 905 970 medical procedures,including 54.81％ for tertiary hospitals,18.00％ for secondary hospitals,16.21％ for primary hospital,and 10.98％ for ungraded hospitals.X-ray photography contributed 71.30％ with annual frequency of 407.84 examinations per 1 000 population,CT scans 21.81％ with annual frequency of 124.74 examinations per 1 000 population,interventional radiology 1.04％,with annual frequency of 5.98 examinations per 1 000 population,and other types of X-ray examinations 5.85％ with annual frequency of 33.47 examinations per 1 000 population.Conclusions The configuration of X-ray diagnostic equipment in Tianjin is basically reasonable.The frequency of X-ray diagnostic medical exposure is increasing year by year.The rationality of the distribution of X-ray diagnostic examinations needs to be further improved.To reduce dose to population,for the public health and safety is important issues in the future of radiation protection.
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Objective@#To investigate the usage frequency of radiological diagnosis devices in ten hospitals in Tianjin, China, and to provide a basis for the survey of medical radiation frequency in Tianjin.@*Methods@#Ten hospitals from the ten districts in Tianjin were enrolled as subjects by a convenient sampling method. A survey was conducted to assess the general information and radiological diagnosis device information and usage frequency in those hospitals in 2016. The radiological examination frequency in Tianjin was estimated.@*Results@#A total of 610 458 patients received radiological examinations in the sampled hospitals in 2016. In those patients, 371 882 received X-ray examinations for imaging and 238 576 for computed tomography (CT) ; there were slightly more female patients than male patients, suggesting a relatively equal gender distribution; patients older than 40 years accounted for 65.53%, which was the highest among all the age groups. Different types of radiological diagnosis devices were mostly used in tertiary and secondary hospitals. In Tianjin, the estimated frequency of X-ray examination for imaging and CT scanning was 451 and 188 per thousand people, respectively, in 2016.@*Conclusion@#The frequency of radiological diagnosis is relatively high in the ten hospitals in Tianjin. The investigation of medical radiation in Tianjin needs to be improved.
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Tong-Mai(TM) granules were composed ofRadix Salviae Miltiorrhizae(Danshen),Rhizoma Chuanxiong(Chuanxiong) andRadix Puerariae(Gegen). It had the effect of activating blood circulation. It had been used to treat ischemic cardio-cerebrovascular diseases in the clinical practice. This research combined serum pharmacochemistry and serum pharmaocology to study the material basis of active components in TM granules. After single or multiple intragastric administrations of TM granules, serum blood samples of rats were collected at different time points. LC-MS/MS method was developed to analyze chemical components of TM in blood serum samples. The cardiomyocyte hypoxia / reoxygenation (H/R) model was used in the evaluation of cardiomyocyte protection by TM. The correlation analysis was also conducted between serum concentration of TM and cardiomyocyte activity. The results showed that 8 components of pueraria flavonoid, 5 components of salvianolic acids and 2 components fromGegen were promptly absorbed and reached their highest concentrations at 5 or 30 min after administration. After 3 times of medication, the serum concentration was obviously higher compared to single medication. The drug-serum of TM showed significant protective effect on the cardiomyocyte H/R injury with dose-effect relationship. Daidzein, lithospermic acid, salvianolic acid A, salvianic acid A and rosmarinic acid presented as the most correlated components linked to the effect of activating blood circulation by TM. The serum pharmacochemistry / serum pharmacology related studies provided references for the verification of material basis of active components in compound Chinese medicine.
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Objective To investigate the expressions of miR-16,miR-106b,miR-449a,miR-34a and let-7g in peripheral blood plasma of the residents surrounding hot springs with radon in Hebei province.Methods A total of 41 randomly selected residents surrounding hot springs with radon were considered as the radon group,and 46 residents with same living habit but without contact with hot springs were considered as control.The miRNAs in the peripheral blood plasma of these two groups were detected with qRT-PCR.Results The levels of miR-16,miR-106b,miR-449a and let-7g in the radon group were significantly higher than those in control group (Z=-2.278,-3.835,-2.719,-2.721,P＜0.05).Alterations of these miRNAs were associated with radon exposure (t =2.154,3.711,2.319,2.015,P ＜ 0.05) but had no relationship with age,sex,smoking and drinking factors.No significant difference was observed in the plasma levels of miR-34a between the two groups.Conclusions miR-16,miR-106b,miR-449a and let-7g could be applied as potential biomarkers for radon exposure.