1.Study on the expansion properties of homemade fast investment material for the IPS-Empress2 castable ceramic.
Gang HE ; Yunmao LIAO ; Yuankun CEN
Journal of Biomedical Engineering 2006;23(1):117-120
IPS-Empress2 is a successful all-ceramic restoration system. To lower its cost, and promote its application, a kind of homemade fast investment material has been developed. The aim of this study was to evaluate the expansion properties of this investment material. The setting expansion, thermal expansion and total expansion of the homemade fast investment material were tested. The same properties of the IPS special fast investment material were also tested as control. Then the SPSS statistics software was used to evaluate the differences between the homemade material and the special material. The results show that the setting expansion rate, thermal expansion rate and total expansion rate of the special investment material for IPS-Empress2 are 0.858%, 1.11% and 1.17% respectively, while the same parameters of the homemade investment material are 0.798%, 1.09% and 1.16% respectively. There is no statistically significant difference in these expansion properties between the two investment materials. In conclusion, the expansion properties of homemade fast investment material are comparable to those of the special fast investment material, so it can compensate for the cast contraction of IPS-Empress2 castable ceramic precisely.
Aluminum Silicates
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chemical synthesis
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chemistry
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Crowns
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Dental Materials
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chemical synthesis
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chemistry
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Dental Porcelain
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chemical synthesis
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chemistry
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Lithium Compounds
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chemical synthesis
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chemistry
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Surface Properties
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Tensile Strength
2.Characterization of homemade fast investment material for the IPS-Empress2 castable ceramic.
Gang HE ; Yuankun CEN ; Zuli SHENG
Journal of Biomedical Engineering 2008;25(3):600-603
The aim of this study is to evaluate the physical and mechanical properties of our homemade investment material for the IPS-Empress2 castable ceramic. The IPS specific investment material was taken as control. Results show that the setting time, density before heating, density after heating, rate of open hole, compressive strength at 2 hours after setting and the compressive strength after heating to 920 degrees C of the homemade investment material are 9 minutes, 1.813 g/cm3, 1.402 g/cm3, 38.1%, 5.42 MPa and 8.37 MPa respectively, which are comparable or even better than the specific material. Under the SEM, the crystals of the phosphate hydrate in our homemade material are smaller than those in the special material. Since the physical and mechanical properties of our homemade investment material are comparable or superior to those of the specific material, a conclusion is drawn that it has a promising prospect of future clinical application.
Aluminum Silicates
;
chemistry
;
Crowns
;
Dental Casting Investment
;
chemical synthesis
;
chemistry
;
Dental Materials
;
chemical synthesis
;
chemistry
;
Dental Porcelain
;
chemistry
;
Lithium Compounds
;
chemistry
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Microscopy, Electron, Scanning
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Shear Strength
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Surface Properties
;
Tensile Strength
3.Surgical correction of supracardiac total anomalous pulmonary venous connection using sutureless technique
Yiqun DING ; Jian ZHUANG ; Jimei CHEN ; Jianzheng CEN ; Shusheng WEN ; Gang XU
Chinese Journal of Thoracic and Cardiovascular Surgery 2010;26(2):73-75
Objective Retrospectively analyze surgical correction supracardiac total anomalous pulmonary venous con-nection (TAPVC) using sutureless technique to prevent post-repair pulmonary vein stenosis. Methods Between December 2007 and December 2008, 25 children cases of total anomalous pulmonary venous connection underwent primary surgical cor-rection. The anatomic types of TAPVC were supra cardiac in nine patients, inha cardiac in one, mixed in 3 and intra cardiac in 12. Five of nine supra cardiac TAPVC underwent correction using sutureless technique. There were 2 male and 3 female. Their age at surgeries ranged from 2 months to 13 years, and the body weight were from 4.5 kg to 2.1 kg with an average of (7.9±6.4) kg. After median sternotomy and opening the pericardium, the heart was arrested by delivering cold crystal ear-dioplegia. The heart was then positioned toward the patient' s right and under the right henri sternum. A generous incision across the posterior wall of the left atrium and one on the common pulmonary vein was made. The latter was extended upwards to the midpoint of the vertical vein. The left atrium was subsequently connected to the pulmonary venous confluence by suturing the edge of the atrium to the posterior mediastinal pericardium that surrounding the common pulmonary vein and the vertical vein with 7-0 PDS. The vertical vein was partially ligated after conclusion of CPB, leaving a diameter of 5mm shunt. Routine follow-up with echocardiogram were at diacharging, 3 months, 6 months and 1 year after surgery. Results All 5 cases survived uneventfully excopt 1 baby on ventilation over 7 days after surgery, who had bilateral lung consolidation before the operation. Echocardiogram showed satisfactory results with maxium velocity acrossing the anastomosis of 0.65 -0.85 m/s. Conclusion Sutureleas technique can avoid trauma to the pulmonary venous endothelium and minimize the tension of anastomasis. It may play an important role to prevent post-repair pulmonary vein stenosis. More patients with long-term follow-up are necessary to draw a definite conclusion of this technique.
4.Long-term effects of vascularized pisiform transfer for Kienb(o)ck's disease
Cong XIAO ; Guoming LIU ; Lin TENG ; Zhou XIANG ; Gang ZHONG ; Shiqiang CEN ; Fuguo HUANG
Chinese Journal of Orthopaedics 2011;31(3):238-242
Objective To evaluate the long-term efficacy of vascularized pisiform transfer for patients with Kienb(o)ck's disease in Lichtman stages Ⅲ-Ⅳ. Methods Eleven patients were reviewed to analyze results after lunate resection and vascularized pisiform transfer for Lichtman stages Ⅲ and Ⅳ. There were six men and five women. Age ranged from 20 to 67 years with a average of 41.0±14.3 years. According to Lichtman stage. There were 4 cases in stage Ⅲa, 5 cases in stage Ⅲb, and 2 cases in stage Ⅳ. Assessment criteria included subjective assessment of pain, visual analogue scale (VAS), range of motion (ROM), grip power,Cooney wrist score and radiographic changes on each follow-up visit. The radiographic changes including pis iform bone location, shape, sclerosis change, osteoarthritis, carpal height ratio, Nattrass index, Radioscaphoid angle and ulnar variance were recorded. Results The follow-up periods of all of cases were 61-202 months,with an average of 104.1 months. Pain had improved in 10 patients and disappeared in 7 cases. The VAS score was 2.2±1.9 at follow-up visit. Range of motion of injured wristw as only 65.3% of opposite side. Grip power was 84.3% of the contralateral hand. According to Cooney score, the results were excellent in 1 case, good in 7cases, fair in 2 cases and poor in 1 case, with the excellent and good rate of 72.7%. Radiologically, 8 cases had normal position of the pisiform bone, 2 had volar displacement and 1 had ulnar displacement which leaded to widen scaphopisiform space. Six pisiform bones had normal trabecular structure, three had degenerative changes. Bone sclerosis was seen in 2 cases and osteoarthritis was found in 3 patients. Compared with radiographic parameter before surgery, carpal height ratio and Nattrass index significantly lowered and radioscaphoid angle significantly increased. Conclusion Lunate resection and vascularized pisiform transfer is an effective method for Kienb(o)k′s disease in stages Ⅲ-Ⅳ. Although carpal collapse appeared postoperatively,the results show high patient satisfaction and good function after vascularized bone transplantation.
5.Konno-Rastan procedure in children with complex multilevel left ventricular outflow tract obstruction
Yiqun DING ; Jian ZHUANG ; Ruobin WU ; Jimei CHEN ; Jianzheng CEN ; Gang XU ; Shusheng WEN
Chinese Journal of Thoracic and Cardiovascular Surgery 2012;(12):705-707
Objective Konno-Rastan procedure is one option to cope with complex multilevel left ventricular outflow tract obstruction (LVOTO),which continues to pose a serious challenge to cardiac surgeons.The aim of this study is to retrospectively analyse indications for Konno-Rastan procedure,and to review the safeguards and pitfalls.Methods Between January 1996 and August 2012,totally 13 children with multilevel LVOTO underwent Konno-Rastan procedure.There were 8 boys and 5 girls.Age at surgeries ranged from 5 to 13 years,and weight from 12 to 51 kg with median of 21 kg.The pathology of this cohort includes:8 cases of congenital aortic valvular stenosis,3 cases of congenital aortic valvular stenosis combined with supravalvular stenosis,1 case of congenital aortic stenosis combined with VSD,coarctation and RVOT obstruction,1 case of aortic stenosis s/p percutaneous balloon aortic valvuloplasty.All patients have secondary diffuse tunnel LVOTO.Diameter of aortic ring ranges from 12.0 to 16.4 mm,and pressure gradient across the stenotic region ranges from 90-151 mm Hg.8 cases were implanted with St.Jude AG19 while 5 cases implanted with St.Jude AG17.Results All 13 cases survived.The 4th patient was implanted permanent epicardial pacemaker for transient Ⅲ AVB.The 4th and 5th patients were found residual ventricular septal repture at the nadir of ventricular incision,one underwent redo procedure while another is being followed up.All cases take cumadine to sustain INR at 1.8-2.5.No death emerges during follow-up period.The motality is 0%,the incidence rate of B is 7.7%,residual VSD 15.4% and endocarditis 7.7%.Conclusion Konno-Rastan procedure is a promising techi.to relieve LVOTO.However,this complex procedure may lead to several fetal complications.Success of the surgery demands perfect operations.
6.Surgical management of atrioventricular valve regurgitation in single-ventricle
Jianzheng CEN ; Jian ZHUANG ; Jimei CHEN ; Yiqun DING ; Gang XU ; Shusheng WEN
Chinese Journal of Thoracic and Cardiovascular Surgery 2014;30(4):199-202
Objective The aim of this article is to review and analyze the timing and surgical management of mediate and severe atrioventricular valve regurgitation(AVVR) in single-ventricle patients.Methods Between June 2006 and October 2011,twenty-three cases of single-ventricle patients accompanied with AVVR underwent atrioventricular valve plasty or replacement.There were 17 males and 6 females.Their ages ranged from 2.1 to 22.0 years,and their weight from 12.5 to 59.0 kg.There were 3 cases of A type of single ventricle,17 of B type,2 of C type,and 1 of D type.All cases had one atrioventricular valve except one of D type with 2 groups of atrioventricular valves.There were 18 patients with sever AVVR and 5 with the moderate.Before the management of AVVR,12 patients had undergone the first stage palliation,including B-D Glenn procedure 11 cases and A-P shunt 1 case.The periods between the two stages operations were 7-96 months.Among the all,there were 7 cases of atrioventricular valve replacement ; 3 cases of atrioventricular valve replacement and TCPC ; 5 cases of atrioventricular valve replacement and B-D Glenn procedure ; 2 cases of atrioventricular valve repair and TCPC ; 4 cases of atrioventricula repair and B-D Glenn procedure; 1 case of atrioventricular valve repair,B-D Glenn procedure and TAPVC repair; 1 case of atrioventricular valve repair,B-D Glenn procedure,PA Banding and TAPVC repair.Results In this group,there were 65.2% patients who underwent atrioventricular valve replacement.The ones with moderate regurgitation underwent atrioventricular valve repair.Only 3 of the 18 cases with severe regurgitation could underwent atrioventricular valve repair(P =0.002).Three cases died.The mortality was 13%.All cases undergone atrioventricular valve repair were alive.The mortality of atrioventricular valve replacement was 20%.All the post-operative alive were followed up.Their follow-up period were between 0.8-6.3 years,withoud a dead case.Conclusion The regurgitation with single ventricle should be managed before the image of myocardium occurred.It is the best time to manage the atrioventricular valve when the regurgitation was moderate.The atrioventricular valve replacement is effective to the cases of single ventricle with severe AVVR.
7.Modified extracardiac Fontan operation with direct total cavopulmonary connection
Xiaobing LIU ; Jimei CHEN ; Jianzheng CEN ; Yiqun DING ; Gang XU ; Shusheng WEN ; Jian ZHUANG
Chinese Journal of Thoracic and Cardiovascular Surgery 2014;30(2):65-67
Objective In order to optimize the Fontan circulation,a technique for direct total cavopulmonary connection was devised.To evaluate its surgical feasibility as well as surgical outcomes,our clinical experience was retrospectively reviewed.Methods From August 2005 to March 2012,23 consecutive patients underwent modified extracardiac Fontan operation with direct total cavopulmonary connection.Clinical profile of the patients,and procedural variables were examined and analyzed.Results All patients had adequately developed main and branch pulmonary arteries.Inferior caval vein was contralateral to the pulmonary trunk main pulmonary artery in 7 cases,ipsilateral in 8,and others in 8.There was 1 hospital death.The other 22 patients remained hemodynamically stable postoperatively.Prolonged effusions (n =13,62%) was a challenging problem.No obvious stenosis was found at the direct cavopulmonary anastomosis.Conclusion we are convinced that a direct total cavopulmonary connection is feasible in select subset of patients.This modified Fontan procedure retains the advantage of extracardiac connections together with the avoidance of prosthetic materials.
8.Transport efficiency and safety evaluation by process management during the handover of patients with tracheal intubation post-operation
Ying PU ; Ying ZHANG ; Gang CEN ; Yueli TONG ; Qi RUAN ; Yinzhen CHEN ; Fang FANG
Chinese Journal of Practical Nursing 2015;31(28):2138-2140
Objective To evaluate transport efficiency and safety by process management during the handover of patients with tracheal intubation post-operation. Methods Prospective studies were performed between patients with or without process management during the handover. The time of handover were recorded and compared. The difference between systolic and diastolic blood pressure, heart rate, and arterial oxygen saturation were also recorded and compared. The adverse events during the handover were also investigated. Results It costed less time in the handover of patients under process management with significant difference[(4.75±0.54) min vs. (7.05±0.88) min, t=-17.21, P<0.01]. The incidence rate of harmful cases in the handover of patients under process management was significantly declined than that without process management[ 1.67%(1/60) vs. 13.33%(8/60),Χ2=4.324 3,P<0.05 ]. Conclusions Process management may facilitate the handover of patients with tracheal intubation post-operation and improve its safety.
9.Compare the result of congenital heart disease surgery of single center in China with Europe
Dandong LUO ; Jian ZHUANG ; Jimei CHEN ; Jianzheng CEN ; Gang XU ; Shusheng WEN ; Hujun CUI ; Lan WU
Chinese Journal of Thoracic and Cardiovascular Surgery 2017;33(5):257-261
Objective The study aimed to explore the development direction of congenital heart disease surgery through comparing Europe with Guangdong General Hospital(GDGH) in data of ECHSA Congenital Database.Methods The data between 2009 to 2015 of Europe and GDGH were extracted from ECHSA Congenital Database.The data of Europe and GDGH were compared by basic information,operating difficulty and mortality.Results The results of Europe and GDGH were patient number(71 763 vs 13 119),procedure/patient ratio(126.2% vs 104.1%),age[(75.91 ± 146.18) months VS(105.80 ± 172.18) months],the proportion of neonate (18.2% vs 4.4%),Aristotle mean score (7.00 vs 6.67),30 days mortality (2.98% vs 1.73 %).The proportion of neonate palliative operation of Europe was more than that of GDGH.In adult group,Europe was more of reoperation and of GDGH was more of primary surgery.Conclusion The surgical treatment of congenital heart disease of GDGH is developing and is close to the mean average of Europe.The proportion of neonate,complex surgery and reoperation is lower than Europe.
10.Repair of pulmonary atresia with ventricular septal defect: choice of right ventricle outflow tract reconstruction
Xinjian YAN ; Jian ZHUANG ; Jiani LI ; Jimei CHEN ; Jianzheng CEN ; Gang XU ; Shusheng WEN
Chinese Journal of Thoracic and Cardiovascular Surgery 2016;32(10):590-594
Objective To compare the two different ways of right ventricular outflow tract(RVOT) reconstruction at repair of pulmonary atresia with ventricular septal defect,the direct RV-PA anastomosis and pericardial conduit to find the better way.Methods From Jun.2002 to Oct.2012,66 patients underwent pulmonary atresia with ventricular septal defect repair in our hospital,age at operation from 14 days to 272 months.Patients were divided into 2 groups according to the way of RVOT reconstruction.Group 1:31 of them,using direct RV-PA anastomasis,Group 2:35 of them,using pericardial conduit.Paired t test was used to evaluate the growth of pulmonary arteries.Chi-square test and Kaplan-Meier were used to calculate the postoperative mortality,reopemtion situation and survival time.Results There are 3 early hospital death in group 1 (9.7 %),and 5 in group 2(14.3%),P =0.71.There is a significant difference between the two groups in restenosis rate of the RV-PA anastomasis and autologous pericardial conduit with pulmonary branch artery(Group 1:22.2%,Group 2:55.6%,P =0.01).The diameters of RV-PA anastomasis and the pulmonary artery branches in follow-up were significantly lager than the earlier diameters(P < 0.05) in group 1.There is no growth on diameters of the pericardial conduit and pulmonary branches except the right pulmonary artery in follow-up in group 2.There is no significant difference between the two groups in later survival(P =0.30).Conclusion Both the direct anastomasis of RV-PA and pericardial conduit are available for RVOT reconstruction in pulmonary atresia with ventricular setal defect repair.There is lower incidence of RVOT and pulmonary stenosis and anastomosis absolutely has the ability for later growth in the former.