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BACKGROUND:Polyetheretherketone is a special plastic polymer with good mechanical properties,biocompatibility,and chemical stability,which can be added with different fillers to form new composite materials and has potential clinical application value in post core repair. OBJECTIVE:To review the properties of polyetheretherketone and its composite materials,as well as the clinical application progress in post core repair. METHODS:CNKI database was searched using the Chinese search terms"polyetheretherketone,post core repair,metal post,fiber post,zirconia post".PubMed database was searched using English search terms"PEEK,polyetheretherketone post,post core repair,dental dowels".Search time ranged from January 2019 to October 2023.By reading literature titles,abstracts,and selecting the entire text,the inclusion and exclusion criteria were used to screen and finally include 71 articles for review. RESULTS AND CONCLUSION:Polyetheretherketone is a high-performance thermoplastic polymer.Experimental studies have proven that polyetheretherketone and its composites have advantages in mechanical properties,biocompatibility,aging resistance,chemical stability,adhesive properties,etc.,and have promising application prospects in the field of post core repair.The clinical application of polyetheretherketone and its composite materials as post core restorations is limited to anterior teeth and premolars,but they have achieved satisfactory restoration results.Polyetheretherketone and its composite materials are new materials in post core repair,and there are still many problems to be solved,such as whether the 3D printing equipment and printing process will affect the mechanical properties of the materials;short observation time for clinical repair effects,lack of long-term research validation.There is a lack of case reports on the use of polyetheretherketone and its composite materials as post and core materials for repairing molars,and further research is needed to continuously improve related studies.
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Objective:To explore the application value of 16-slice spiral CT multi-planar reconstruction(MPR), surface occlusion display and other image post-processing techniques in the diagnosis of peripheral lung cancer.Methods:From April 2017 to April 2019, a total of 98 patients with peripheral lung cancer admitted to the Affiliated Hospital of Hangzhou Normal University and the First People's Hospital of Jiashan County were selected.The detection rates of various signs of MPR, surface occlusion display and other image post-processing techniques in the diagnosis of peripheral lung cancer were analyzed and compared.Results:MPR in the diagnosis of peripheral lung cancer, the lobulated sign was 94.9%(93/98), the vascular bundle sign was 85.7%(84/98), the fine and short burr was 93.9%(92/98). The detection rate of vascular bundle sign and fine burr sign was higher than that of thin layer scan (χ 2=5.351, 5.023, 5.777, all P<0.05). There was no statistically significant difference between MPR and thin-layer scan in vacuolar sign and pleural indentation (χ 2=1.356, 1.333, all P>0.05). The surface occlusion in the diagnosis of peripheral lung cancer, showed 90.8%(89/98) lobulated sign and 74.5%(73/98) pleural indentation.The detection rates of lobulated sign and pleural sag were higher than those of thin layer scanning (χ 2=5.450, 6.002, all P<0.05). The detection rate of vacuole sign by surface occlusion in peripheral lung cancer diagnosis was lower than that of thin layer scan ( χ 2=5.013, P<0.05). The surface occlusion had no statistically significant difference compared with thin layer scan in the detection rate of vascular bundle sign and thin and short burr sign in the diagnosis of peripheral lung cancer (χ 2=1.256, 1.302, all P>0.05). Conclusion:In the diagnosis of various signs of peripheral lung cancer, the detection rate of 16-slice spiral CT MPR technique is high and worthy of application.
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Objective@#To explore the diagnostic performance of susceptibility weighted imaging (SWI)in distinguishing benign or malignant soft tissue tumor, and to study pathological observation.@*Methods@#Sixty-eight patients with soft tissue tumor, who received no previous treatment or invasive examination, received routine preoperative MRI examination and SWI scanning. The graduation and distribution of intratumoral susceptibility signal intensity(ITSS) and proportion of tumor volume were observed.The pathological results were also included for comparative analysis.@*Results@#Fourty of 68 patients were benign and 28 were malignant. 72.5% (29/40) patients with benign soft tissue tumors were ITSS grade 1 and ITSS grade 3 (hemangioma). 89.3%(25/28) patients with malignant soft tissue tumors were ITSS grade 2 and ITSS grade 3. The difference was statistically significant (P<0.01). The distribution of ITSS in patients with benign soft tissue tumors was dominated by peripheral distribution and diffuse distribution (hemangioma), accounting for 90.0% (36/40). The distribution of ITSS in patients with malignant soft tissue tumors mainly distributed in the central region, accounting for 78.6% (22 /28). The difference was statistically significant (P<0.01). The proportion of tumor volume occupied by ITSS in benign soft tissue tumors was <1/3 and> 2/3 (hemangioma), accounting for 90.0% (36/40). The volume of malignant soft tissue tumors were predominantly <1/3 , accounting for 82.1% (23/28). The difference was statistically significant (P<0.01).@*Conclusion@#SWI is sensitive in displaying the vein and blood metabolites in soft tissue lesions, which is helpful for the differential diagnosis of benign and malignant tumors in soft tissue.
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A special device for measuring the pull-out force of orthodontic micro implant was designed, which has the characteristics of simple construction and easy operation, and can be used to detect the pull-out-force of orthodontic micro implant. The tested data was stored and analyzed by a computer, and as the results, the pull-out-force curve, maximum pull-out force as well as average pull-out force were outputted, which was applied in analyzing or investigating the initial stability and immediate loading property of orthodontic micro implant.
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Desenho de Equipamento , Ortodontia , MétodosRESUMO
Objective To evaluate the accuracy and clinical efficacy of low field phase-contrast magnetic resonance angiography(PC-MRA),CTA and 3D-DSA in the diagnosis of cerebrovascular disease.Methods 70 patients with clinically suspected cerebrovascular diseases were examined with PC-MRA,CTA and 3D-DSA.The sensitivity in detecting the cerebrovascular disease with these three methods were compared.Results Fifty-one patients were detected with cerebrovascular diseases in seventy patients by three imaging methods,including 36 aneurysms in 33 cases and 18 arteriovenous amlformations.33,34 and 35 aneurysms,17,16 and 18 arteriovenous malformations were detected by PC-MRA , CTA and 3D-DSA respectively , the sensitivity were 91.67% and 94.44%,94.44% and 88.89%,97.22% and 100% respectively.There were no significant difference in the sensitivity of detecting aneurysm and arteriovenous malformation between these three imaging methods(P>0.05).Conclusion PC-MRA,CTA and 3D-DSA are no of difference in diagnosis of cerebrovascular malformation.