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15 July 2012, Volume 16 Issue 29 Previous Issue    Next Issue

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Osteoinductivity of chitosan/nano-hydroxyapatite bioelectret barrier membranes Ao Dan-ting, Wang Yan-ying, Wang Ping, Qu Yi-li, Man Yi, Chen Zhi-qing 2012, 16 (29):  5321-5326.  doi: 10.3969/j.issn. 2095-4344.2012.29. 001 Abstract ( 371 )   PDF (555KB) ( 481 )   Save BACKGROUND: Currently, the barrier membranes that applied in guided bone regeneration have no osteoinductivity. OBJECTIVE: To explore the effects of composite bioelectret membranes after polarization on compatibility and activity of osteoblasts. METHODS: Chitosan/nano-hydroxyapatite bioelectret composite membranes were prepared by grid-controlled corona charge. The surface potential decay of the membranes and the proliferation and differentiation of osteoblasts seeded on them were evaluated. RESULTS AND CONCLUSION: The surface potential was obviously reduced in 1 day, but the speed of decay slowed gradually during the following 9 days. Compared with the unpolarized group, the osteoblasts on the bioelectret membranes had clearer boundaries and more pseudopodia. Moreover, the proliferation ability and alkaline phosphatase activity of the cells seeded on bioelectret membranes were higher than those of the unpolarized group (P < 0.05). But the direct immunofluorescence showed no significant difference in actin between the two groups. In conclusion, bioelectret mebrane is a new type of barrier membrane with osteoinductivity and can improve the proliferation and differentiation of osteoblasts. Related Articles | Metrics

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Nano-hydroxyapatite artificial bone serves as a spacer for fusion with the cervical spine after bone grafting Liu Wu-yang, Mo Jian-wen, Gao Hui, Liu Hai-li, Wang Mao-yuan, He Chun-lei, Tang Wen, Ye Yong-jun 2012, 16 (29):  5327-5330.  doi: 10.3969/j.issn. 2095-4344.2012.29. 002 Abstract ( 385 )   PDF (341KB) ( 561 )   Save BACKGROUND: In recent years, allograft bone and coral bone have been commonly used as the spacers after double-door expansive laminoplasty, which can easily result in rejection and non-fusion. OBJECTIVE: To verify the effect of nano-hydroxyapatite artificial bone on posterior double-door expansive laminoplasty in the cervical spine. METHODS: Totally 46 patients undergoing posterior double-door expansive laminoplasty in the cervical spine received nano-hydroxyapatite artificial bone as the spacers. All patients were followed-up for over 3 months. Japanese Orthopaedic Association (JOA) scores before and after nano-hydroxyapatite artificial bone grafting were compared. The fusion of bone graft with the cervical spine was detected by X-ray and CT. RESULTS AND CONCLUSION: At final follow up, JOA scores were increased from preoperative (7.9±1.9) points to (12.1±2.8) points. No patients were found cervical spine instability as well as loosening and displacement of the bone graft postoperatively. The fusion between the nano-hydroxyapatite artificial bone and spinous process was good. These findings suggest that the nano-hydroxyapatite artificial bone is an ideal bone graft substitute material and applicable to double-door expansive laminoplasty. Related Articles | Metrics

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Preparation and pharmacokinetics of brucine immuno-nanoparticles Qin Jian-min, Yang Lin, Sa Zhong-qiu, Huang Tao, Sheng Xia, Li Qi, Yin Pei-hao, Zhang Min, Gao Ke-pan, Chen Qing-hua, Ma Jing-wei, Shen He-bai 2012, 16 (29):  5331-5335.  doi: 10.3969/j.issn.2095-4344.2012.29.003 Abstract ( 294 )   PDF (435KB) ( 404 )   Save BACKGROUND: Brucine is highly toxic and insoluble in water, as well as has narrow intravenous therapeutic window. The amount of poisoning and treatment is close. Therefore, brucine is limited in clinical treatment of liver cancer and other malignant tumors. OBJECTIVE: To prepare the brucine immuno-nanoparticles and to observe the characteristics of the drug metabolism in vivo. METHODS: Anionic polymerization and chemical modification technology were used to prepare carboxylated polyethylene glycol-poly lactic acid copolymer. Phacoemulsification technology was employed to prepare carboxylated polyethylene glycol-polylactic acid copolymer brucine nanoparticles. Then, chemical coupling technology was utilized to combine the anti-human alpha-fetoprotein monoclonal antibody with the polyethylene glycol-poly lactic acid copolymer brucine nanoparticles to prepare the brucine immuno-nanoparticles with immune targeting. RESULTS AND CONCLUSION: Brucine immuno-nanoparticles showed uniform size with an average particle size of (249±77) nm and Zeta potential of (-18.7±4.19) mV. The encapsulation efficiency was (76.0±2.3)% and the drug load was (5.6±0.2)%. Brucine immuno-nanoparticles were very stable in the medium with an accumulative release rate of over 80% in 24 hours and 100% in 48 hours. Brucine immuno-nanoparticles belonged to non-compartment model during in vivo metabolic process. The half life period of brucine immuno-nanoparticles was (15.69±3.77) hours, which was longer than that of the brucine (P < 0.01). The brucine immuno-nanoparticles with immune targeting are successfully prepared that belong to non-compartment model during in vivo metabolic process, and show sustained-release properties. Related Articles | Metrics

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Ordered nanopore arrays on the surface of diameter-controlled anodic alumina influence the adhesion behavior of umbilical vein endothelial cells Ni Si-yu, Zhang Yan-fei, Ni Shi-rong 2012, 16 (29):  5336-5340.  doi: 10.3969/j.issn. 2095-4344.2012.29. 004 Abstract ( 289 )   PDF (631KB) ( 370 )   Save BACKGROUND: Studies have shown that many types of cells can influence the surface structure of micrometer scale on material surfaces. OBJECTIVE: To observe the effect of various pore sizes of ordered nanopore arrays on diameter-controlled anodic alumina on the adhesion behavior of human umbilical vein endothelial cells (hUVECs). METHODS: The order arranged porous anodic alumina (PAA) with controllable pore sizes (25, 50, 65 or 75 nm) was prepared using a two-step anodizing procedure in oxalic acid electrolytes. The hUVECs were seeded on the PAA surface with different pore sizes to evaluate the cellular adhesion behavior on the PAA surface. RESULTS AND CONCLUSION: The hUVECs adhered well on the surfaces of all the PAA specimens and showed a normal morphology. MTT assay showed that the hUVECs adhesion rates were significantly higher on the surface of the PAA with larger diameter of 75 nm compared with the PAA with smaller diameter of 25 nm after 4 and 24 hours of culture (P < 0.05). It is indicated that the PAA with larger diameter of 75 nm can promote the cell adhesion compared with the PAA with smaller diameter of 25 nm based on its better biological activity. Related Articles | Metrics

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Effect of calcium phosphate nanoparticles on biological behaviors of MG63 cells Cao Jun, Cai Yu-rong, Ma Yin-sun, Yao Ju-ming 2012, 16 (29):  5341-5344.  doi: 10.3969/j.issn. 2095-4344.2012.29. 005 Abstract ( 273 )   PDF (478KB) ( 386 )   Save BACKGROUND: Several studies have shown that many features of nanomaterials can influence nanomaterials toxicity obviously, such as their size, shape and crystallinity. OBJECTIVE: To explore the effect of material shapes on the biological behaviors of MG63 cells and to analyze the correlations between their physical-chemical properties and biological effect by using three kinds of calcium phosphate nanoparticles with different shapes. METHODS: Spherical, fusiform and rod-like calcium phosphate nanoparticles were synthesized by hydro-thermal method and chemical precipitation method and filmed on the glasses. The size, shape, roughness and crystallinity of calcium phosphate nanoparticles and their films were characterized by transmission electron microscope, field emission scanning electron microscopy, atomic force microscopy, dynamic light scattering and X-ray diffraction. MG63 cells were seeded and cultured on films. Effects of calcium phosphate on the biological behaviors of MG63 were detected, including adhesion, proliferation, differentiation, and apoptosis. RESULTS AND CONCLUSION: The results showed that the shape and crystallinity of calcium phosphate influenced MG63 cells proliferation obviously. Calcium phosphate nanoparticles with high aspect ratio and high crystallinity could promote cells proliferation, and conversely, calcium phosphate nanoparticles with low aspect ration and low crystallinity could inhibit cells proliferation. MG63 cells were sensitive to the roughness of calcium phosphate films, and cell adhesion ability was decreased with the increase of the roughness of calcium phosphate films. These findings suggest that the three kinds of calcium phosphate can promote cells migration effectively, but there are no obvious influences on cells differentiation and apoptosis. Related Articles | Metrics

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Intervertebral fusion cage made by poly-amino acid/hydroxyapatite composites in a goat cervical spine model Peng Lei, Quan Zheng-xue, Tan Chao, Ou Yun-sheng, Tang Ke 2012, 16 (29):  5345-5349.  doi: 10.3969/j.issn.2095-4344.2012.30.024 Abstract ( 298 )   PDF (474KB) ( 328 )   Save BACKGROUND: Poly-amino acid/nano-hydroxyapatite composite material has been proved to have a good bio-security. OBJECTIVE: To evaluate the fusion effect of poly-amino acid/nano-hydroxyapatite interbody cage in a goat cervical spine model. METHODS: Sixteen adult male goats underwent C3-4 discectomy and intervertebral fusion with poly-amino acid/nano-hydroxyapatite interbody cage (experimental group, n=8) or autogenous iliac (control group, n=8). X-ray was taken at 2, 4, 8 and 12 weeks after surgery to measure the intervertebral height. CT scanning and histology examination were performed at 4 and 12 weeks after surgery. RESULTS AND CONCLUSION: Referring to radiography and histomorphology findings, the goats with poly-amino acid/nano-hydroxyapatite cage or autograft all showed fine fusion at 12 weeks, without significant difference. The intervertebral fusion cage of poly-amino acid/nano-hydroxyapatite has good initial stability and fusion which may be an ideal interbody fusion appliance. Related Articles | Metrics

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Platelet-rich fibrin combined with self-setting calcium phosphate cement for repairing jaw defects Xu Yong-liang, Wang De-li, Xu Wen-xiu 2012, 16 (29):  5350-5354.  doi: 10.3969/j.issn. 2095-4344.2012.29. 007 Abstract ( 361 )   PDF (522KB) ( 392 )   Save BACKGROUND: Choukroun’s platelet-rich fibrin (PRF) and self-setting calcium phosphate cement (CPC) can enhance the repair of bone defects, but either one has its limitation in clinical application. Whether the combination of the two materials can achieve a better effect remains unclear. OBJECTIVE: To investigate the effect of PRF combined with CPC on jaw defect repair. METHODS: Totally 40 patients were divided into two groups randomly. The experimental group (n=20) was filled with the combination of PRF and CPC, while the control group (n=20) was filled with CPC only. RESULTS AND CONCLUSION: In the experimental group, there was a boundary between jaw bone defect area and the surrounding jaw bone tissues, and new bone formed after treatment for 1 month. After 3 months of treatment, the boundaries between bone defect area and the surrounding normal jaw bone tissues were blurred, besides, bone mineral density in bone defect area began to increase and a large number of trabecular bone formed. After 6 months of treatment, the boundaries between the defect area and surrounding normal bone were unclear, and normal bone morphology appeared. In the control group after 6 months of treatment, the boundaries between new bone and the surrounding normal bone were marked, and bone density in the bone cavity of defects area was lower than that in the experimental group at the same period (P < 0.05). These findings suggest that the combination of Choukroun’s PRF and CPC can obviously promote bone growth in patients with jaw defects. Related Articles | Metrics

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Histological structure of porcine aortic valve scaffolds decellularized by using different methods Ma Hao, Wang Qi, Shi Hai-yan, Wang Li-xin, Zhang Xiao, Li Ze-jian, Miao Qi 2012, 16 (29):  5355-5360.  doi: 10.3969/j.issn.2095-4344.2012.29.008 Abstract ( 249 )   PDF (749KB) ( 355 )   Save BACKGROUND: An ideal decellularization method cannot only remove donorcells completely to decrease immunogenicity, but also reserve the extracellular matrix of natural valve, such as collagen and elastic fibers to keep sufficient mechanical strength. OBJECTIVE: To prepare porcine aortic valve scaffolds decellularized by different methods and to compare their tissue structures, as well as to explore the most effective methods for preparing decellularized valve scaffolds. METHODS: Totally 20 fresh porcine aortic valve scaffolds were randomly divided into four groups: control group, detergent group, enzymatic digestion group and detergent+enzymatic group. Decellularized valve scaffolds in the latter three groups were prepared by Triton X-100, Trypsin and Triton X-100+Trypsin methods, respectively. The valve scaffolds were contrasted by gross observation, hematoxylin-eosin and Mallory-Heidenhain staining, scanning and transmission electron microscope. RESULTS AND CONCLUSION: (1) After decellularized, the valve leaflets in the detergent group were soft and smooth. Besides, Hematoxylin-eosin staining showed that the cells were removed from the valve, but few nucleoli remained and fibers were arranged regularly. Mallory-Heidenhain staining showed that the blue collagen and the red elastin were interlaced. Electron microscope observation showed that the fibers presented with wave-like arrangement and lateral stripes could be observed. (2)The valve leaflets in the enzymatic digestion group were collapsed partly, but their endothelium was smooth. Hematoxylin-eosin staining showed that the cells were removed completely and the connective tissue structures were loose. Mallory-Heidenhain staining showed that collagen and elastin were found reticulated interlacing. Electron microscope showed that some fibers were ruptured, but lateral stripe existed. (3)The valve leaflets in detergent + enzymatic group was collapsed partly, but their endothelium was smooth. Hematoxylin- eosin staining showed that the cells were removed completely from valve. Mallory-Heidenhain staining showed that collagen and elastin showed parallel arrangement. Electron microscope observation showed that fibers were intact but scattered, and lateral stripe can be observed. These findings suggest that Triton X-100, Trypsin and Triton X-100+ Trypsin methods can remove valve cells effectively and keep the fibers intact; moreover, the Triton X-100 + Trypsin method is more effective. Related Articles | Metrics

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Mechanical strength of porcine small intestinal submucosa used as a tissue-engineered tendon scaffold Sun Wen-cai, Li Yu-cheng, Li Bo, Jiang Xin, Li Xiao-long, Chen Yong-chun, Bai Yu-jiang 2012, 16 (29):  5361-5365.  doi: 10.3969/j.issn. 2095-4344.2012.29. 009 Abstract ( 232 )   PDF (494KB) ( 382 )   Save BACKGROUND: Small intestinal submucosa is a good scaffold material for cell migration, growth and proliferation, which has been applied in tissue engineering research. OBJECTIVE: To analyze the feasibility of porcine small intestinal submucosa used as the tendon scaffold for tissue engineering METHODS: Totally 24 Roman chicken with flexor tendon defects of the left leg were randomly divided into experimental group and control group. The composite of porcine small intestinal submucosa and flexor digitorum profoundus tendon in chicken embryos were implanted into the defect area of chicken in the experimental group. The chicken in the control group were implanted with isolated porcine small intestinal submucosa to their defects. Maximum tensile strength of tendon materials in the two groups were detected at weeks 3, 6 and 9 after implantation. RESULTS AND CONCLUSION: At week 3 after implantation, in terms of the maximum tensile strength of tendon materials, there was no significant difference between the experimental group and control group. At weeks 6 and 9 after implantation, the maximum tensile strength of tendon materials in the experimental group was higher than that in the control group (P < 0.05). These findings suggest that the mechanical strength of tissue-engineered tendon scaffolds composited by tendon cells and small intestinal submucosa is stronger than that of tendon repaired by the pure small intestinal submucosa. Small intestinal submucosa can be used as a tendon scaffold material for tissue engineering. Related Articles | Metrics

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Effects of post space and post core preparation at different time on apical microleakage with fiber post sealing Xiao Yue, Yu Jia, Wang Jian-ping, Guo Hai 2012, 16 (29):  5366-2370.  doi: 10.3969/j.issn. 2095-4344.2012.29. 010 Abstract ( 371 )   PDF (413KB) ( 425 )   Save BACKGROUND: The vibration of high speed turbine handpiece during post space and post core preparation has an adverse effect on the continuous force of the bonding interfaces among the cement, dentin and post core, which influences the apical sealing effect of post core. OBJECTIVE: To investigate the effects of post space and post core preparation at different time on apical microleakage with fiber posts system. METHODS: Totally 55 extracted mandibular premolars each with single root canal were biomechanically prepared by using the step back technique. The samples were divided into five groups randomly: the immediate post space preparation group, 2 days after post space preparation group, 1 week after post space preparation group, a positive control group and a negative control group. Each group was averagely divided into three subgroups and they all were mixed for 15, 30 and 60 minutes on the cements, and then performed post core preparation. After that, all roots were dyed and transparentized. The dyeing scores of apical microleakage in each group were recorded under stereoscopic microscope observation. RESULTS AND CONCLUSION: The score of apical microleakage in 1 week after post space preparation group was obviously higher than that in 2 days after post space preparation group. There were significant differences between the two groups (P < 0.05). No significant difference was shown for the microleakage of post core preparation after mixed for 15, 30 and 60 minutes on the cements (P > 0.05). These findings suggest that the immediate post space preparation can play a good protective effect on apical sealing. In terms of fiber posts, there are not effects of post core preparation at different time on apical microleakage after the same kind of cement solidified completely. Related Articles | Metrics

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Bond strength of colored zirconia core materials with veneering cermaics Jiang Xu 2012, 16 (29):  5371-5374.  doi: 10.3969/j.issn. 2095-4344.2012.29. 011 Abstract ( 305 )   PDF (338KB) ( 512 )   Save BACKGROUND: Bond failure between the core and veneering ceramics is the most common cause of failure in all-ceramic restorations. Several studies have shown that the accession of colored granules can decrease the bond strength of zirconia cores materials with veneering ceramics, thereby influencing the success ratio of zirconia restorations. OBJECTIVE: To test shear bond strength of four kinds of colored zirconia core materials and veneering ceramics, as well as to investigate the effect of colored granules on the bond strength of zirconia cores materials with veneering ceramics compared with white zirconia cores materials. METHODS: White and colored Lava Frame, IPS E.max Zircad, Vita In-Ceram Zirconia, Cercon Smart zirconia blanks and their corresponding veneering ceramics were produced into disks with a diameter of 7 mm and a thickness of 3 mm following each manufacturers’ recommendations, such as spray sand and ultrasonic cleaning. At the center of core materials, the veneering ceramics each manufacturer recommended were veneered with handmade porcelain method. After that, the volume of veneering ceramics (with diameter of 5 mm, and thickness of 3 mm) was controlled by homemade stencils and sintered. RESULTS AND CONCLUSION: The shear bond strength between four kinds of colored zirconia based combinations and white zirconia based combinations had no significant difference (P > 0.05).These showed that the accession of colored granules had no influence on the bond strength between zirconia and veneering ceramics. The proportions of failures at the zironia-ceramic combinations interface and shear bond strength values from high to low were Lava, IPS E.max, Vita In-Ceram Zirconia and Cercon, respectively. Focal laser scanning microscope showed that the failure mode of combinations at fractured surface was cohesive failure within the veneering ceramics and interface adhesion failure. Besides, the major failure was cohesive failure within the veneering ceramics rather than core failure. Related Articles | Metrics

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Repair of meniscal cartilage injuries in the avascular zone of rabbits by using porous silk fibroin/hydroxyapatite combined with bone marrow mesenchymal stem cells Zhu Xian-wei, Xu Wei-yuan, Zhang Xing-xiang, Wang Chuang-li, Wang Li-ming, Sha Wei-ping, Zhu Yin 2012, 16 (29):  5375-5378.  doi: 10.3969/j.issn.2095-4344.2012.29.012 Abstract ( 382 )   PDF (515KB) ( 456 )   Save BACKGROUND: With the emergence of tissue engineering, the possibility of meniscal repair in the avascular zone is greatly increased, but single scaffold materials fail to meet an ideal scaffold and have certain limitations. OBJECTIVE: To investigate the effect of silk fibroin/hydroxyapatite (SF/HA) combined with bone marrow mesenchymal stem cells (BMSCs) on repairing meniscal cartilage injuries in the avascular zone of rabbits. METHODS: Rabbit BMSCs were isolated, cultured and induced into fibrochondrocytes, and then cultured with SF/HA. A rabbit model of unilateral meniscal cartilage injuries in the avascular zone was established. A total of 42 rabbits were randomly divided into three groups. Compound group was implanted with the compound of BMSCs and SF/HA, pure material group was implanted with SF/HA and control group had no treatment. RESULTS AND CONCLUSION: The results of general observation showed that the injured tissue had been filled in the compound group. And the repair effect was improved gradually at weeks 8-12, which was similar to the normal meniscus tissue and superior to the other two groups. The results of histological examination exhibited cartilage capsule and collagen fibers arranged in disorder at week 8, and meniscus injuries were completely repaired in the compound group at week 12. Meniscus injuries were partly repaired with scar healing in the pure materials group. The control group was not found cartilage injuries healing. The results of MRI examination indicated that the repair effect of the compound group was the best. These findings suggest that the method of BMSCs combined with SF/HA is feasible to repair meniseal cartilage injuries in the avascular zone, and the SF/HA can be used as scaffold materials for meniscal cartilage tissue engineering due to its good biocompatibility. Related Articles | Metrics

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Xenogeneic cancellous bone for repairing segmental bone defects in rabbit radius Wei Ji-rong, Zhang Ying, Lin Yong-liang 2012, 16 (29):  5379-5383.  doi: 10.3969/j.issn. 2095-4344.2012.29. 013 Abstract ( 252 )   PDF (532KB) ( 334 )   Save BACKGROUND: Xenogeneic cancellous bone has a natural porous structure that facilitates the ingrowth of new bone. Besides, its antigenicity can be eliminated completely after treatment and cannot induce immune rejection. Moreover, it has good bone conduction. OBJECTIVE: To evaluate the effect of xenogeneic bone on the repair of segmental bone defects in rabbit radius. METHODS: Totally 36 rabbits (4-6 months old, 2.5-3.5 kg, no gender limitations) were randomly divided into three groups: experimental group, control group and blank group. A rabbit model of 15 mm-long segmental bone defects in the radius was established. Rabbits in the experimental group were implanted with biological xenogeneic bone, and those in the control group were implanted with deep frozen allogenic bone, while the blank group had no treatment. At weeks 4, 8 and 12 after operation, rabbits in the three groups were observed by general observation, anatomy observation, X-ray examination and histological examination. RESULTS AND CONCLUSION: At weeks 4, 8 and 12 after operation, bone defects in the experimental and control groups were repaired gradually, but no repair was found in the blank group. The radiographic and histological scores were both higher in the experimental and control groups than the blank group (P < 0.05). The radiographic and histological scores between the experimental and control groups had no significant difference. These results suggest that biological xenogeneic bone is good to repair bone defects; in addition, the repair effect of biological xenogeneic bone is the same as that of xenogeneic bone. Related Articles | Metrics

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Feasibility of guided bone tissue regeneration technique to conserve the alveolar ridge: Two kinds of bone substitutes Gao Xiao-wei, Li Ke 2012, 16 (29):  5384-5388.  doi: 10.3969/j.issn. 2095-4344.2012.29. 014 Abstract ( 320 )   PDF (398KB) ( 385 )   Save BACKGROUND: The ideal bone materials for guiding bone tissue regeneration can maximally recover hard and soft tissue morphology of tooth extraction fossa, which are conducive to the success of dental grown. OBJECTIVE: To compare the effects of different guided bone tissue materials on extraction socket in early reconstruction. METHODS: A total of 60 patients required the extraction of the teeth, and they were randomly divided into three groups with 20 teeth in each. The teeth were extracted and the different guided bone tissue materials were implanted. Bio-Oss and hydroxyapatite were implanted into the Bio-Oss and hydroxyapatite groups after tooth extraction, and no treatment was done in the control group. RESULTS AND CONCLUSION: The heights of the proximal alveolar bone and the interdental papilla as well as the width of lip to lingua were changed little in the Bio-Oss group, more in the hydroxyapatite group, and most in the control group. It can prove that Bio-oss is the best guided bone tissue material in conserving the alveolar ridge after tooth extraction. Related Articles | Metrics

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Calcium phosphate cement/epimedium composite materials for improving fracture healing of osteoporotic rats Yin Hong, Qian Wei-qing 2012, 16 (29):  5389-5395.  doi: 10.3969/j.issn. 2095-4344.2012.29. 015 Abstract ( 225 )   PDF (596KB) ( 417 )   Save BACKGROUND: Epimedium can promote the proliferation and differentiation of osteoblasts. OBJECTIVE: To observe the effects of calcium phosphate cement (CPC)/epimedium composite materials on fracture healing of osteoporotic rats. METHODS: Sprague Dawley rats were randomly divided into control group and experimental group. Ovariectomy-induced osteoporosis rat models were established in the experimental group, while surgical excision of a small amount of fatty tissue around the ovaries was performed in the control group. Cancellous bone fracture was prepared in the distal end of the right femur of rats in the experimental group, and the rats were subdivided into three groups for treatment: Kirschner wire group, CPC group and CPC/epimedium group. RESULTS AND CONCLUSION: Alkaline phosphatase activity: increasing in varying degrees of alkaline phosphatase activity could be seen in the three groups at 2, 4 and 8 weeks after treatment, and the improvement in alkaline phosphatase activity of the CPC/epimedium group was the highest (P < 0.05). At 12 weeks, alkaline phosphatase activity of the CPC/epimedium group returned to normal, and those of the other two groups maintained a high level despite some decrease. Biomechanical detection: the maximum load of the CPC/epimedium group was obviously higher than those of the two other groups (P < 0.05), and the rate of increase in the maximum load of the CPC/epimedium group was the highest. Histological examination: fibrous osteotylus and bone callus of the CPC/epimedium group appeared more early, and both the quantity and the quality of new bone were superior to those of the other groups. It is indicated that the CPC/epimedium artificial bone possesses a good osteoinductive activity, and can improve the fracture healing of osteoporotic rats. Related Articles | Metrics

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Comparison of cytotoxicity among three gingival retraction cords on human gingival fibroblasts in vitro Ni Ying, Zhang Xiao-ming, Hui Min, Liu Jian 2012, 16 (29):  5396-5400.  doi: 10.3969/j.issn. 2095-4344.2012.29. 016 Abstract ( 247 )   PDF (527KB) ( 328 )   Save BACKGROUND: In recent years, the gingival retraction effect of gingival retraction drugs is a hot topic for domestic and foreign scholars, while the biocompatibility of the commercial gingival retraction cord is less involved. OBJECTIVE: To evaluate the cytotoxicity effect of three kinds of gingival retraction cords on human gingival fibroblasts, and to provide theoretical basis for choosing proper gingival retraction cords in clinic. METHODS: Three kinds of gingival retraction cords (epinephrine-impregnated cord, aluminium sulphate-impregnated cord and non-drug-impregnated cord) were incubated in Dulbecco’s modified Eagle’s medium containing 10% fetal bovine serum for 24 hours, according to 1:1 and 1:4 dilution, and then the cords acted on gingival fibroblasts cultured in vitro. Dulbecco’s modified Eagle’s medium containing 10% fetal bovine serum was used as negative control group. RESULTS AND CONCLUSION: The results of MTT assay demonstrated that the three kinds of gingival retraction cords all could inhibit human gingival fibroblasts growth and proliferation. The cytotoxicity of the three kinds of gingival retraction cords in the leaching liquor with 1:1 dilution was significantly higher than that of 1:4 dilution and control groups (P < 0.05). The cytotoxicity of epinephrine-impregnated cord in the leaching liquor with 1:4 dilution was significantly higher than that of the control group (P < 0.05). The results of transmission electron microscope showed that some cells in the epinephrine-impregnated cord group were found apoptosis. These findings suggest that the three kinds of gingival retraction cords all have certain cytotoxicity to gingival fibroblasts. The cytotoxicity of epinephrine-impregnated cord is the biggest, followed by aluminium sulphate-impregnated cord, and the cytotoxicity of the non-drug-impregnated cord is the smallest. Related Articles | Metrics

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Effect of the combination of glial cell line-derived neurotrophic factor, NogoA and chondroitin sulfate ABC microspheres on promoting the neural regeneration of rat’s injured spinal cord Zhang Yu, Song Yue-ming 2012, 16 (29):  5401-5406.  doi: 10.3969/j.issn. 2095-4344.2012.29. 017 Abstract ( 312 )   PDF (1844KB) ( 419 )   Save BACKGROUND: Previous studies have shown that glial cell line-derived neurotrophic factor (GDNF) exhibits good effect on the regeneration of the injured spinal cord. OBJECTIVE: To investigate the effect of the combination of the injured chondroitin sulfate ABC (ChABC), GDNF and NogoA microspheres on the regeneration and functional recovery of the injured spinal cord in rats. METHODS: Totally 64 adult SD female rats were randomly divided into eight groups: normal control group, sham operation group (only laminectomy), model group, GDNF group, ChABC microspheres group, GDNF microspheres group, NogoA microspheres group, ChABC+GDNF+NogoA microspheres group. T10 total transected spinal cord models were established in all groups except for normal control and sham operation groups, and the broken ends of the injured spinal cord were injected a half of liquid medicine, and then the back of the broken ends were covered by the other half of liquid medicine which was absorbed by latin sponge. RESULTS AND CONCLUSION: ①Basso, Beattie and Bresnahan (BBB) Locomotor Rating scores: ChABC+GDNF +NogoA microspheres group was higher than the model, GDNF, GDNF microspheres, ChABC and NogoA microspheres groups at weeks 5, 6, 7, 8, 9 and 10 after treatment (P < 0.05). ②Cortical somatosensory evoked potential (CSEP) at week 10 after treatment: no detection was found in the sham operation , model and GDNF groups. CSEP in main reaction latency of the ChABC+GDNF+NogoA microspheres group was lower than that of other groups (P < 0.05), but higher than that of the normal control group (P < 0.05). The peak value of the main reaction peak in the ChABC+GDNF+NogoA microspheres group was higher than that in other groups (P < 0.05), but lower than that in the normal control group (P < 0.05). These findings suggest that the combination of GDNF, NogoA and ChABC microspheres can promote the regeneration, functional recovery and nerve conduction of the spinal cord in rats, which is superior to that of pure GDNF microspheres. Related Articles | Metrics

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Inhibitory effect of poly (lactic-co-glycolic acid) microspheres containing docetaxel intratumoral injection on the proliferation of human triple negative breast cancer xenograft in nude mice Ke Li-ming, Zhang Xiu-juan, He Yi-mi, Lin Li-wu, Xue En-sheng, Chen Zhi-kui 2012, 16 (29):  5407-5411.  doi: 10.3969/j.issn. 2095-4344.2012.29. 018 Abstract ( 315 )   PDF (504KB) ( 491 )   Save BACKGROUND: Under ultrasound guidance, intratumoral injection of sustained-released chemotherapeutics for tumor interstitial chemotherapy can improve antitumor and decrease systemic toxicity and side effects. OBJECTIVE: To investigate the inhibitory effect of poly (lactic-co-glycolic acid) (PLGA) microspheres containing docetaxel intratumoral injection under ultrasound guidance on the proliferation of human triple negative breast cancer xenograft. METHODS: Sustained-release PLGA microspheres containing docetaxel was prepared by solvent evaporation method. The morphology and particle size were observed by scanning electron microscope. The drug loading rate, entrapment efficiency and in vitro release were examined by high performance liquid chromatography. The human triple negative breast cancer-bearing nude mouse model was established and divided into five groups: model group (with no treatment), microspheres group (injected blank PLGA microspheres), docetaxel intratumoral injection group (injected 10 mg/kg docetaxel and administrated once every 10 days for 40 days continuously), PLGA microspheres containing docetaxel low-dose group (injected drug-released microspheres intratumorally: 20 mg/kg docetaxel one time) and PLGA microspheres containing docetaxel high-dose group (injected 40 mg/kg docetaxel one time) RESULTS AND CONCLUSION: The mean particle size of prepared PLGA microspheres containing docetaxel was detected as 23.1 μm with an optimal entrapment efficiency of 96.3%, drug loading rate of 4.82%, and cumulative release drug rate of 85.7% within 40 days. Under ultrasound guidance, intratumoral injection of PLGA microspheres containing docetaxel displayed a potent antitumor effect on human triple negative breast cancer xenograft. And the tumor inhibition rate of the high-dose group had reached 65.7%. Color Doppler ultrasound showed the tumor blood supply was significantly decreased. Pathological examination indicated that the tumor tissues were found a great of putrescence. These findings suggest that interstitial chemotherapy by using ultrasound-guided intratumoral injection of PLGA microspheres containing docetaxel can significantly inhibit the proliferation of human triple negative breast cancer xenograft. Related Articles | Metrics

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Vascular endothelial regeneration after small-diameter bioartificial vascular graft Lin Lü-biao, Xu Yi-min, Qi Song-tao, Zeng Shao-wen, Li Wei-qiu, Zhuang Bing-rong 2012, 16 (29):  5412-5416.  doi: 10.3969/j.issn.2095-4344.2012.29.019 Abstract ( 472 )   PDF (522KB) ( 479 )   Save BACKGROUND: Characteristics of vascular prostheses are similar to the natural vessels and it has high histocompatibility after transplantation. But endothelial regeneration is the key for vascular prosthesis unblocked eternally. OBJECTIVE: To investigate the histocompatibility of a novel small-diameter bioartificial vascular graft at different periods postoperatively and the histopathologic changes following intimal regeneration of the vessel wall. METHODS: A dog model of artificial vascular grafts implanted end-to-end by a continuous suture in the common carotid artery was established. RESULTS AND CONCLUSION: ①Light microscope results showed that at week 12 after graft, endothelial cells were sparsely distributed throughout the neointima surface near the stoma; at month 6 after graft, endothelial cells were presented on the whole surface of the patent graft lumen; 1.5 years after graft, lumens of graft vessels were unobstructed, and parts of endomembrane tissues were found chronic inflammation. ②Electron microscope results showed that at week 12 after graft, new vascular endothelial cells were in fusiform shape and arranged regularly; besides, the endothelial cells spread from the stoma to the middle of the graft vessel. After graft for 6 months, the endothelial cells spread from the stoma to the middle of the graft vessel. Endothelial cell colony in the middle of the graft vessel showed leaping and flake-like growth, and the cells were arranged more compactly; moreover, their shapes were more like the endothelial cells of mature vessels. After graft for 1.5 years, the whole vessel wall was covered by tightly arranged endothelial cells, and parts of endomembrane tissues revealed chronic inflammation. These findings suggest that the novel small-diameter bioartificial vascular graft has many advantages, for example, the newborn intima forms early and completely, and endangium can be well reconstructed; in addition, it has good biocompatibility and stability. Related Articles | Metrics

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Fabrication of a tubular vascular scaffold with circumferential microchannels to induce oriented growth of smooth muscle cells Zhang Qing, Feng Jie, Zheng Yi-xiong, Zhong Ming-qiang 2012, 16 (29):  5417-5422.  doi: 10.3969/j.issn.2095-4344.2012.29.020 Abstract ( 267 )   PDF (583KB) ( 511 )   Save BACKGROUND: In vascular tissue engineering, scaffolds that can induce smooth muscle cells align and orientate in circumferential direction, but not simple porous scaffold, would be welcome. OBJECTIVE: To observe the effect of circumferential microchannels on the in vitro induction of smooth muscle cells. METHODS: Electrospinning, melt spinning, and solvent adhesion techniques were combined and the as-prepared scaffolds were further modified by grafting collagen for improving their biocompatibility. Scanning electron microscope and fluorescence microscope were selected to characterize the alignment of smooth muscle cells on these biomimetic scaffolds. RESULTS AND CONCLUSION: Mixture of chloroform/alcohol with volume ratio at 5:95 was used to bond the elextro spun poly(lactic-co-glycolic acid) fibers and melt spun poly(ε-caprolactone-co-lactic acid) fibers successfully toward creating a biomimetic vascular scaffold. The scaffold surface was first introducing active carboxylate group by alkali hydrolyzing and then coupling with collagen by using carbodiimide. When the weaving angle in the melt spinning was suitable (30°), the pores of the scaffold could ensure the growth of smooth muscle cells on and in the scaffold homogenously. All the smooth muscle cells aligned along the microfibers and microchannels of the scaffolds, demonstrating that such novel type of scaffold had strong ability in inducing smooth muscle cells regenerating their microarchitecture in vivo. It is helpful in developing biomimetic tubular scaffold to induce blood vessel regeneration in vivo. Related Articles | Metrics

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Synthesis of poly(p-dioxanone) Cui Man-man, Gong Lian-sheng 2012, 16 (29):  5423-5427.  doi: 10.3969/j.issn.2095-4344.2012.29.021 Abstract ( 472 )   PDF (513KB) ( 450 )   Save BACKGROUND: Poly(p-dioxanone), as an aliphatic polyester, has its special characters comparing with other aliphatic polyesters. Except for its ultimate biodegradability due to the existence of ester bonds in polymer chains, the unique ether bonds endue it with good flexibility. OBJECTIVE: To explore the optimal conditions for chemical synthesis of poly(p-dioxanone). METHODS: Poly(p-dioxanone) was synthesized by ring-opening polymerization of p-dioxanone using stannous octoate as catalyst in bulk at 80, 100 and 140 ℃ for 10, 20 and 30 hours. Temperature and reaction time effects on the synthesis of homopolymers were observed. RESULTS AND CONCLUSION: The aliphatic homopolymer poly(p-dioxanone) is successfully synthesized by ring-opening polymerization of p-dioxanone using stannous octoate as catalyst in bulk. Based on the monomer conversion rate, the optimal conditions for the synthesis of homopolymers are 100 ℃ for reaction temperature and 20 hours for reaction time. Related Articles | Metrics

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Characterization and biocompatibility of silk fibroin/hyaluronic acid composite porous scaffolds Fan Zhi-hai, Lu Fu-nan, Zhang Feng, Shen Yi-xin 2012, 16 (29):  5428-5432.  doi: 10.3969/j.issn. 2095-4344.2012.29. 022 Abstract ( 260 )   PDF (501KB) ( 398 )   Save BACKGROUND: Silk fibroin and hyaluronic acid with good biocompatibility have the features of protein and glycosaminoglycan in the extracellular matrixs. OBJECTIVE: To prepare silk fibroin/hyaluronic acid composite scaffolds using lyophilization, and to evaluate their characterization and cellular biocompatibility. METHODS: The silk fibroin/hyaluronic acid composite scaffold was prepared by lyophilization at a ratio of 10:1 and characterized by scanning electron microscope and Fourier Transform infrared spectroscopy. Passages 3-5 bone marrow mesenchymal stem cells from rats at a density of 1×108 cells/L were seeded on the silk fibroin/hyaluronic acid composite scaffold to observe cellular biocompatibility by scanning electron microscope and Laser confocal microscope. RESULTS AND CONCLUSION: The silk fibroin/hyaluronic acid composite scaffold was successfully prepared by lyophilization, showing better porous three-dimensional structure compared with pure silk fibroin scaffold. Good cell adhesion, spreading and proliferation behavior on the silk fibroin/hyaluronic acid composite scaffolds were observed, indicating that the cellular biocompatibility of the composite scaffolds is preliminarily confirmed. Related Articles | Metrics

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Preparation and cell compatibility of demineralized bone matrix/sodium alginate composite Xu Wei-jun, Li Bao-xing, Zhang Yu-min, Liu Xiao-ming, Li Jing, Wang Xu-sheng, Ma Shao-ying 2012, 16 (29):  5433-5436.  doi: 10.3969/j.issn. 2095-4344.2012.29. 023 Abstract ( 379 )   PDF (419KB) ( 373 )   Save BACKGROUND: It is important to prepare a bone substitute material with good osteoacusis, osteoinductive activity and cell compatibility that is easily molded, which is of significance to repair irregular bone defects and refractory bone fractures. OBJECTIVE: To prepare demineralized bone matrix/sodium alginate (DBM/ALG) composite material and to screen out the optimal composite ratio, as well as to evaluate its cell compatibility. METHODS: DBM was prepared from the cortical bone of healthy donors by cleaning, grinding and demineralization. According to the ratio of 5/5, 6/4, 7/3, 8/2, the DBM was compounded with ALG, and the DBM/ALG composite material was prepared through screening the optimal ratio by disperse diameter method. L-929 fibroblasts of mice were cultured in the leaching liquor of DBM/ALG, and the cytotoxicity was tested by MTT method at days 2, 4 and 7. RESULTS AND CONCLUSION: With the increase of ALG content, the viscosity of DBM/ALG was strengthened and dispersed diameter was reduced gradually. When the ratio of DBM/ALG was 7/3, DBM/ALG was not discrete easily, and dispersed diameter was 3.7 cm in 37 ℃ water. The results of MTT showed that cell proliferation rates were 91.56%, 95.43% and 97.47% at days 2, 4 and 7, respectively; while cytotoxicity was in grade 1. Related Articles | Metrics

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Effect of quercetin chitosan composite film on superoxide dismutase activity and malondialdehyde content in oral ulcer and wound tissues Zhao Zhi-yu, Guo Lan, Zhao Yu-mei, Han Shu-ying 2012, 16 (29):  5437-5440.  doi: 10.3969/j.issn. 2095-4344.2012.29. 024 Abstract ( 404 )   PDF (390KB) ( 396 )   Save BACKGROUND: Quercetin chitosan composite film was prepared by natural absorbable chitosan and quercetin which have anti-inflammation and accelerating effects on wound healing, and natural absorbable chitosan served as film carriers. A primary observation through an animal model on the pharmacological functions of the composite film was done. OBJECTIVE: To investigate the therapeutic effects of quercetin chitosan composite film on oral ulcer in rats induced by NaOH. METHODS: A SD rat model of oral ulcer induced by NaOH was established. A total of 80 SD rats were randomly divided into four groups: composite film group was given quercetin chitosan composite film, chitosan film group was given chitosan film, Bingpeng San group was given Bingpeng San and control group received no treatment. Each group was dosed twice a day until the oral ulcer in rats was healed completely. Besides, 10 rats from each group were selected, and a rat model of full-thickness back skin defects on both sides of the spine was established. On day 2 after the model was established, the composite film group was treated with quercetin chitosan solution; the chitosan film group was treated with chitosan solution; the Bingpeng San group was smeared with Bingpeng San solution and the control group underwent no treatments. These groups were dosed twice a day for 3 days. RESULTS AND CONCLUSION: Compared with the control group, the ulcer area of the composite film group at each time point was smaller (P < 0.01). At days 2 and 4 after administration, the ulcer area of the composite film group was also smaller than that of the Bingpeng San group (P < 0.05). The composite film group was obviously better than the control group at the degrees of ulcer infection (P < 0.01). There was no significant difference between the composite film group and Bingpeng San group. The superoxide dismutase activity in the wound tissue of rats in the composite film group was significantly higher than that in the control group (P < 0.01), while malondialdehyde content in the composite film group was lower than that in the control group (P < 0.01). These findings suggest that quercetin chitosan composite film can promote ulcer wound healing, which may be related with the increase of superoxide dismutase activity and the decrease of malondialdehyde content in the wound tissue. Related Articles | Metrics

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Preparation of calcium alginate-chitosan tissue engineering scaffolds by a freeze-drying method Li Qin-hua, Wang Di 2012, 16 (29):  5441-5444.  doi: 10.3969/j.issn. 2095-4344.2012.29. 025 Abstract ( 263 )   PDF (633KB) ( 466 )   Save BACKGROUND: High water content is related to the composition of composite scaffolds. Sodium alginate is a polymer material with high water absorption, and chitosan has hydrophilicity. Therefore, the combination of these two materials has high water content as sodium alginate. OBJECTIVE: To construct calcium alginate-chitosan composite scaffolds for tissue engineering by mainly using chitosan and sodium alginate. METHODS: Chitosan and sodium alginate were compounded in various proportions and formed in different ways by orthogonal experiment and single factor experiment methods. The water content and swelling ratio of the composite scaffolds were measured. The histological morphology of the cross-sections of scaffolds was observed by scanning electron microscope. RESULTS AND CONCLUSION: The water content of the scaffolds was 77.20% for the film-forming method, 75.27% for the freeze-drying method, and 97.13% for particle forming method. These findings suggest that the scaffolds prepared in various ways have different cellular structures. Different forming methods have different influences on scaffold properties. Calcium alginate-chitosan scaffolds have high water content and swelling ratio as well as abundant cellular structures, which can be used as tissue engineering scaffolds. Related Articles | Metrics

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Application and progress of heparin-coated technology in biomedical materials Gao Wen-qing, Li Tong, Yu Mei-li 2012, 16 (29):  5445-5449.  doi: 10.3969/j.issn. 2095-4344.2012.29. 026 Abstract ( 382 )   PDF (538KB) ( 951 )   Save BACKGROUND: For the past few years, the application of heparin coating technology is an active field in biomedical materials. Coating methods, coating models and coating materials are in great development. OBJECTIVE: To summarize the investigative situation and progression about different coating models in accordance with different methods and protection of heparin active groups. METHODS: A computer-based research was performed in CNKI database, PubMed database and US patent database to search the related articles about the application of heparin coating technology in biomedical materials. The key words were “heparin, coating technology, bond method, medical materials, anticoagulation activity” in Chinese and English. The articles related to the heparin coating technology were selected, and articles in the same field that published recently or in authorized journals were preferred. There were 161 articles after the initial survey. Then 29 articles related to heparin coating technology were involved according to the inclusion criteria. RESULTS AND CONCLUSION: Heparin coating technology can simulate the anticoagulant mechanism of vascular endothelial cells, and improve the biocompatibility and anticoagulation activity through modification of biomedical materials surface. Heparin coating technology will make great development and application by increasing the stability and quantity of bonded heparin and retaining heparin activity on biomaterial surface. Related Articles | Metrics

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Research progress in the biocompatibility of metal ceramic alloys Xie Yun, Wang Min, Lou Bei-yan 2012, 16 (29):  5450-5454.  doi: 10.3969/j.issn. 2095-4344.2012.29. 027 Abstract ( 441 )   PDF (644KB) ( 726 )   Save BACKGROUND: Studies have shown that the incidence of local adverse effects of gingival and periodontal tissues after fixation of metal-ceramic crowns may relate to the release of metallic elements by the metal-ceramic restorations. OBJECTIVE: To analyze and summarize the biocompatibilities, cytotoxicities, cell metabolisms and mechanisms in molecular levels of non-noble metal-ceramic and noble metal-ceramic alloys. METHODS: A search of studies published from January 1990 to January 2012 related to the effects of metal-ceramic alloys on normal physiological metabolism and immunology of cells was performed in PubMed database and Wanfang database using the key words of “dental casting alloys, biocompatibility, cytotoxicity, cytokines” in English and in Chinese, respectively. Articles irrelative to this paper and repetitive studies were excluded. Finally, 39 literatures were chosen to summarize. RESULTS AND CONCLUSION: The cytotoxicities of five metal-ceramic alloys commonly used in clinical practice are in order of nichrome alloy, titanium alloy, cobalt-chromium alloy, palladium-based alloy, gold alloy. Noble metal-ceramic alloys have good mechanical properties, anti-tarnish and corrosion-resistant properties, good processing properties, and good cytocompatibilities and biocompatibilities. The genotoxicity of gold alloy is superior to nichrome alloy, titanium alloy and cobalt-chromium alloy. Gold alloy can be well used in dentistry based on its good biological properties. For non-noble metal-ceramic alloys, Co-Cr-Mo has the highest biosafety, Ni-Cr-Be has the lowest biosafety, and the biosafety of Ni-Cr is between those of Co-Cr-Mo and Ni-Cr-Be. Noble metal-ceramic alloys are not easy to be porcelain fractured based on their better bond strengths of metal-porcelain compared with non-noble metal-ceramic alloys. Gold coatings can disperse the gathered internal stress to strengthen the bond strength of metal-porcelain through relief the interface stress based on their own elastic yield. Related Articles | Metrics

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Difficulty assessment system of root canal treatment and research status of root canal filling materials Zhou Yan-qin, Zhong Xiao-bo 2012, 16 (29):  5455-5459.  doi: 10.3969/j.issn. 2095-4344.2012.29. 028 Abstract ( 266 )   PDF (608KB) ( 591 )   Save BACKGROUND: The choice of root canal filling materials can affect the quality of root canal filling. The quality of root canal filling is an important key factor that affects the long-term results of root canal treatment. OBJECTIVE: To review the difficulty assessment of root canal treatment and research status of root canal filling materials at home and abroad in recent years. METHODS: PubMed and VIP databases (1990/2011) were searched by the first author for papers concerning the risk factors for the difficulty of root canal treatment and the effect of root canal filling materials on the quality of root canal treatment. RESULTS AND CONCLUSION: Root canal treatment is the most effective method for pulpal and periapical diseases, but its effectiveness is affected by many factors. Therefore, it is necessary to have a difficulty assessment of root canal treatment before treatment. During the treatment, difficult root canal treatment requires advanced therapeutic instruments to lay a good foundation for root canal filling technology. Root canal filling is a key step of the treatment, and the filling result directly influences the effectiveness and the prognosis of root canal treatment. The imprecision of filling can cause microleakage, which can result in the treatment failure due to the root canal reinfection. Therefore, the success or failure of root canal treatment largely depends on the tight filling or not. At present, there is not a kind of root canal material that can completely seal the root canal system. It is needed to further improve the difficulty assessment system of root canal treatment and to study the ideal root canal filling materials in future research. Related Articles | Metrics

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Research status of inorganic silver-carrying antibacterial agent in oral prosthodontics Li Qing-yan, Zheng Xin-ying, Lü Qiao, Lin Hua, Gao Ning 2012, 16 (29):  5460-5464.  doi: 10.3969/j.issn. 2095-4344.2012.29. 029 Abstract ( 319 )   PDF (602KB) ( 368 )   Save BACKGROUND: Oral environment is bacterial, and so the effects of restorative treatments face challenges from micro-organisms. To some extent, the success of treatment depends on the antimicrobial properties of restorative material. The silver antibacterial agent has become a research hotspot for its characteristics of broad spectrum antimicrobial, high biological security and rare drug tolerance. OBJECTIVE: To review the application and research of inorganic silver-carrying antibacterial agent in prosthodontics material and provide a theoretical basis for the further clinical application. METHODS: CNKI, PubMed and OVID databases were retrieved online for articles concerning the application of inorganic silver-carrying antibacterial agent in oral prosthodontics from 1990-01 to 2011-04. Articles highly related to the application and research of inorganic silver-carrying antibacterial agent in oral prosthodontics that published recently or in the authorized journals were included. Twenty-nine articles were included in result analysis. RESUTS AND CONCLUSION: Silver is an effective antibacterial material and has a good effect on oral common pathogenic bacteria, such as candita albicans, streptococcus mutans and lactobacillus. Application of silver into prosthodontics material has a broad prospect. However, silver ion is unstable and tarnished easily. In the modification study of prosthodontics material, it is needed to further research for overcoming oxidizing discoloration, reducing the affection of silver on material physical and chemical properties, as well as the clinical application and evaluation of prosthodontics material. Related Articles | Metrics

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Bone cement implantation during percutaneous vertebroplasty for the treatment of thoracolumbar vertebral fractures Liu Shen-peng, Liu Zhong-he, Zhao Bin, Xu Hai-bin 2012, 16 (29):  5465-5468.  doi: 10.3969/j.issn.2095-4344.2012.29.030 Abstract ( 252 )   PDF (568KB) ( 626 )   Save BACKGROUND: In recent years, percutaneous vertebroplasty as a safe and effective minimally invasive surgery has been widely used in the treatment of osteoporotic compression fractures and vertebral tumor-induced osteolytic bone destruction, and has obtained satisfactory results. OBJECTIVE: To explore the correlation between bone cement and the curative effect of thoracolumbar vertebral fractures by percutaneous vertebroplasty. METHODS: The VIP database and PubMed database were used to search the articles related to the clinical research of percutaneous vertebroplasty and bone cement implantation with the key words of “pereutaneous vertebroplasty, PVP, thoracic vertebra, lumbar vertebra, vertebral fracture, bone cement” in Chinese and English, respectively. A total of 22 articles were included to review. Forty cases (56 vertabral bodies) with the pain induced by thoracolumbar vertebral fractures were selected from the Department of Orthopedics, the First Affiliated Hospital of Xinxiang Medical University for the clinical validation. The percutaneous vertebroplasty was completed under the guidance of C-arm X-ray machine. The improvement of pain was observed after surgery, and the occurrence of the complications was analyzed. RESULTS AND CONCLUSION: At present, the commonly used pereutaneous vertebroplasty bone cement includes polymethyl methacrylate bone cement, calcium phosphate cement and calcium sulfate bone cement. The volume and the composition of bone cement required for the sufficient stability of fracture healing and prevention of pain is remains unclear, but we should try to use small doses of bone cement and make the bone cement evenly distributed. Meanwhile, we should select an appropriate injection method based on different situations of the vertebra in order to prevent the leakage of bone cement and new vertebral fractures. The clinical validation results show that percutaneous vertebroplasty is an effective analgesic method, and postoperative follow-up shows that the analgesic effect and the injection amount of bone cement has no positive correlation, and the pain will not weakened over time. Related Articles | Metrics

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The research and application of artificial lung membrane materials Hu Min 2012, 16 (29):  5469-5476.  doi: 10.3969/j.issn.2095-4344.2012.29.031 Abstract ( 1593 )   PDF (584KB) ( 1123 )   Save BACKGROUND: The artificial lung is a life-support technology and can be used when pulmonary failure occurs and the lung cannot maintain adequate oxygen supply for human organs. In view of the long-term development, the artificial lung can be implanted into the human body to partially or completely replace the lung permanently. At present, studies addressing the artificial lung are focused on gas exchange capacity and biocompatibility to provide more reliable means to rescue the lives of patients through the improvement of membrane materials, optimizing design as well as experimental and clinical evaluations. OBJECTIVE: To analyze the literatures on the artificial lung membrane materials through Scopus database and CNKI database, and to understand the status and trends of the artificial lung membrane materials. METHODS: Retrieval was performed for the literature about the artificial lung membrane materials, using key words of artificial lung, membrane materials, biocompatibility, membrane oxygenator, membrane-type artificial lung, hollow fiber, polymer materials between 2002-01 and 2011-12 in Scopus database and CNKI database. RESULTS AND CONCLUSION: The structure of the artificial lung membrane has been developed from drum, plate folding to microporous hollow fiber membrane which is widely used now. The hollow fiber materials are mainly polymers with high performance of fiber formation, such as polypropylene and poly(ether sulfone). Membrane-type artificial lung can improve gas exchange and biocompatibility. With the development of new technologies and materials, the advance of basic research as well as the accumulation of clinical experience, the artificial lung is bound to initiate new insight in the treatment of severe respiratory disorders. A total of 172 papers on the artificial lung membrane materials published between 2002-01 and 2011-12 were retrieved in Scopus database, in which most of papers were published as original articles. The overall number of literature is more stable, and there is no significant increasing. Artificial Organs published most papers in this field. Related Articles | Metrics

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Collagen/chitosan hemostatic dressings in surgical wounds Gao Wen-biao, Zhang Yan-rui, Zhang Jun 2012, 16 (29):  5477-5480.  doi: 10.3969/j.issn.2095-4344.2012.29.032 Abstract ( 314 )   PDF (540KB) ( 1021 )   Save BACKGROUND: Chitosan combined with collagen can be more effective to stop the bleeding. OBJECTIVE: To assess the material properties and biocompatibility of collagen/chitosan hemostatic dressing materials in surgical wounds. METHODS: A computer-based search was performed for articles addressing biological dressings, collagen/chitosan hemostatic materials in wounds or during wound hemostasis published from January 2000 to June 2010. The keywords were “biomaterial, hemostatic material, gauze, collagen/chitosan, biocompatibility” in Chinese and “biomaterial, hemostatic material, bioresorbable material, hemostasis effect, hemostatic mechanism” in English. RESULTS AND CONCLUSION: Chitosan has unique biological properties that are characterized to have a broad-spectrum antibacterial activity, to promote epithelial cell growth and hemostasis, promote wound healing, and have a good biodegradability and tissue compatibility, which can be used for treatment of fingertip injury and granulation wound. Chitosan can be applied to prepare wound dressings, absorbable sutures, hemostatic materials, anti-blocking agent, drug delivery and tissue engineering scaffolds for wound treatment under field conditions. Related Articles | Metrics

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Clinical investigation of enamel decalcification around the brackets after fixed orthodontic treatment Zhang Ying-jie, Cao Bao-cheng, Li Miao, Jiao Xin, Wang Jing, Wang Pu 2012, 16 (29):  5481-5484.  doi: 10.3969/j.issn. 2095-4344.2012.29. 033 Abstract ( 300 )   PDF (364KB) ( 484 )   Save BACKGROUND: Enamel decalcification around the brackets is one of the most common complications after fixed orthodontic treatment. There are no reports about the onset characteristics of enamel decalcification after fixed orthodontic treatment in teenagers and adults. OBJECTIVE: To investigate the incidence of enamel decalcification around the brackets after fixed orthodontic treatment in teenagers and adults. METHODS: 140 patients who underwent fixed orthodontic treatment at School of Stomatology, Lanzhou University from 2005-01 to 2009-07 were chosen, including 78 teenagers and 62 adults. The incidence and severity of enamel decalcification were observed and evaluated before and after treatment. RESULTS AND CONCLUSION: ①The enamel decalcification was observed in 122 cases, and the incidence rate was 87.14%. The incidence rate of the teenager group was significantly higher than that of the adult group (P < 0.05). ②Totally 536 teeth had enamel decalcification, and the incidence was 16.86%. 320 of 1 784 teeth in the teenager group had enamel decalcification, and the incidence rate was 17.94%. 216 of 1 395 teeth in the adult group, and the incidence rate was 15.48%.③The incidence rates of maxillary teeth in teenagers and adults were both obviously higher than those of mandibular teeth (P < 0.05). The enamel decalcification often occurred in maxillary incisor teeth. It is indicated that the incidence rate of enamel decalcification after fixed orthodontic treatment is high, and clinical measures should be taken to prevent and cure it. Related Articles | Metrics

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Anterior debridement and fusion with freeze-dried bone allografts in children with spinal tuberculosis Mardan·Mamat, Ren Long-long, Tian Juan, Sheng Wei-bin, Jin Ge-le, Yang Yi, Lu Yun 2012, 16 (29):  5485-5488.  doi: 10.3969/j.issn.2095-4344.2012.29.034 Abstract ( 331 )   PDF (371KB) ( 355 )   Save BACKGROUND: The anterior fixation can reconstruct the stability and support functions of the spinal column, and meanwhile, promote fusion through providing compressive stress between the bone grafts bed and bone graft. OBJECTIVE: To study the application of anterior debridement and fusion with freeze-dried bone allografts in treating pediatric spinal tuberculosis. METHODS: Twenty-seven children with spinal tuberculosis were collected and analyzed retrospectively. All the patients were treated by anterior debridement, allogeneic bone grafting and internal fixation. Then, anti-tuberculosis treatment lasted for 12-18 months in all the 27 cases. RESULTS AND CONCLUSION: All of the patients were followed up for 6 months to 2.5 years. According to Bridwell criteria, there were 14 cases of Ⅰ grade, 11 cases of Ⅱ grade, two cases of Ⅲ grade. Five of the 27 cases were accompanied by incomplete paralysis of the lower limbs and recovered after internal fixation, including three cases of grade D and two cases of grade E according to Frankel grading. Debridement surgery and internal fixation with allogeneic bone grafting were respectively implemented at 3 months and 6 months after operation in one case of C6-7 tuberculous because of sinus formation, fixation loosening and shedding and allogeneic bone collapse. Another case of thoracic spine tuberculosis at T9-11 segments presented with mild kyphotic deformity that the Cobb’s angle was 20°, as well as bone growth retardation occurred after the anterior fixation was removed and posterior interbody fusion was performed. These findings indicate that it is safe and feasible to carry out anterior debridement and fusion with freeze-dried bone allografts in children with spinal tuberculosis on the basis of systemic anti-tuberculosis. Related Articles | Metrics

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New charged calcium sulfate/beta-tricalcium phosphate compound bone cement for unilateral and bilateral transpedicular vertebroplasty: Bone cement leakage and biomechanics changes Qin Yi, Jiang Jian-ming, Zhu Qing-an, Qu Dong-bin, Yang Yong, Liu Peng 2012, 16 (29):  5489-5492.  doi: 10.3969/j.issn. 2095-4344.2012.29. 035 Abstract ( 293 )   PDF (356KB) ( 293 )   Save BACKGROUND: A new type of charged calcium sulfate/beta-tricalcium phosphate compound bone cement can restore vertebral mechanical properties, and meanwhile reduce the risk for bone cement leakage in traditional vertebroplasty and improve operation safety. OBJECTIVE: To study bone cement leakage and vertebral biomechanical changes by observation of the new charged calcium sulfate/beta-tricalcium phosphate compound bone cement in unilateral and bilateral transpedicular vertebroplasty. METHODS: Osteoporotic thoracolumbar specimens selected from eight old male corpses were used to prepare a vertebral compression fracture model. Two successive vertebral specimens were paired to be cross-assigned into unilateral and bilateral groups. In the unilateral group, 4 mL of new charged calcium sulfate/beta-tricalcium phosphate compound bone cement was applied in unilateral transpedicular vertebroplasty; 4 mL of new charged calcium sulfate/beta-tricalcium phosphate compound bone cement was used for bilateral transpedicular vertebroplasty in the bilateral group, 2 mL at each side. RESULTS AND CONCLUSION: The leakage volume of bone cement in the unilateral group was significantly higher than that in the bilateral group (P < 0.05). There was no significant difference in the maximum load and stiffness between the two groups (P > 0.05). Bilateral transpedicular vertebroplasty with new charged calcium sulfate/beta-tricalcium phosphate compound bone cement is better, and the decreased volume of injected bone cement helps to reduce the leakage risk of bone cement. However, there is no difference between the vertebral biomechanical changed of the two groups. Related Articles | Metrics

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Percutaneous kyphoplasty with bone cement repairs elderly acute severe osteoporotic compression fractures in 62 cases Liu Bing-zhi, Li Yan-bao, Liu Zhen-wu, Zhao Wei-guang, Yan Ji-ying, Yang Zhao-hui, Xie Yan-ping, Liu Li 2012, 16 (29):  5493-5496.  doi: 10.3969/j.issn.2095-4344.2012.29.036 Abstract ( 337 )   PDF (369KB) ( 411 )   Save BACKGROUND: Percutaneous kyphoplasty has become widely recognized as an effective method to treat elderly patients with acute severe osteoporotic compression fractures, but the number of cases involved in the relevant literature is less. OBJECTIVE: To explore the clinical effect of percutaneous balloon kyphoplasty on acute severe osteoporotic compression fractures in the elderly. METHODS: A total of 62 elderly patients with acute severe osteoporotic compression fractures (87 vertebrae) were treated with percutaneous balloon kyphoplasty, 2.5-7.1 mL bone cement for one vertebra. All the patients were followed up for over 3 months to observe changes in various indexes. RESULTS AND CONCLUSION: Patients receiving percutaneous balloon kyphoplasty had a significant improvement in the vertebral height and scores on visual analog scale (P < 0.01). No death or spinal cord/nerve injury occurred. Leakage of polymethyl methacrylate was found in two cases from anterior longitudinal ligament, one case from the vertebral arch, and one case from the intervertebral space. No infection and embolism happened, and the vertebral height recovered ≥75%. All patients had pain relief, including two cases of low back pain that relieved following oral administration of analgesic drug. Final follow-up results showed that the vertebral height had no changes. These findings indicate that percutaneous balloon kyphoplasty is safe and effective to treat acute severe osteoporotic compression fractures in the elederly. Related Articles | Metrics

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Application of bone morphogenetic protein 2 loaded nano-hydroxyapatite artificial bone in the correction and fusion of adult idiopathic scoliosis Hu Wen, Huang Qi-kai, Su Jia-can, Li Ming 2012, 16 (29):  5497-5500.  doi: 10.3969/j.issn. 2095-4344.2012.29. 037 Abstract ( 317 )   PDF (380KB) ( 331 )   Save BACKGROUND: Bone morphogenetic protein 2 (BMP-2) loaded nano-hydroxyapatite artificial bone has unique biological properties that can imitate the component and structure of natural bone. It can provide cells a microenvironment which is similar to that of natural bone. OBJECTIVE: To investigate the clinical effects of BMP-2 loaded nano-hydroxyapatite artificial bone and allogeneic bone grafting on the correction and fusion of adult idiopathic scoliosis. METHODS: A retrospective review of 69 patients with adult idiopathic scoliosis was performed. These patients were randomly divided into two groups: group A and group B. In group A, 36 patients were received BMP-2 loaded nano-hydroxyapatite artificial bone; in group B, 33 patients were received allogeneic bone grafting. The anterioposterior and lateral full spinal films were taken at 3 and 6 months after operation, and the spinal fusion status in the two groups were observed and compared. RESULTS AND CONCLUSION: All patients with adult idiopathic scoliosis have corrected obviously. The two groups were all found bone trabecula growth in the radiographs at 3 and 6 months. At 6 months after operation, 33 patients in group A and 26 patients in group B had fused significantly, and early fusion rate of group A was higher than that of group B (P < 0.05). These findings suggest that BMP-2 loaded nano-hydroxyapatite artificial bone is an ideal artificial material for bone transplantation in the correction and fusion of adult idiopathic scoliosis, which is superior to allogeneic bone in spine fusion. Related Articles | Metrics

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Core decompression with bone graft and porous tantalum rod insertion for avascular necrosis of the femoral head Zhong Gui-hua 2012, 16 (29):  5501-5505.  doi: 10.3969/j.issn.2095-4344.2012.29.038 Abstract ( 366 )   PDF (400KB) ( 321 )   Save BACKGROUND: Core decompression with bone graft is a common method for avascular necrosis of the femoral head clinically. With the development of biomechanics research on the femoral head, porous tantalum rod insertion is more and more used for avascular necrosis of the femoral head. However, the comparative study between the two methods is rarely reported. OBJECTIVE: To contrast the clinical effect of core decompression with bone graft and porous tantalum rod insertion on avascular necrosis of the femoral head. METHODS: Totally 36 patients (45 hips) with avascular necrosis of the femoral head were selected, and 15 patients in them (19 hips) underwent core decompression with bone graft, while 21 patients (26 hips) underwent porous tantalum screw insertion. RESULTS AND CONCLUSION: All patients were succeeded in operation and followed up for 3-12 months. There was no significant difference between the two groups in intraoperative blood loss, surgical time and hospital days. Harris hip score was significantly increased postoperatively (P < 0.05). The average Harris hip score of porous tantalum rod insertion group was higher than that of core decompression with bone graft group. There was a significant difference between the two groups (P < 0.05). These findings suggest that compared with the core decompress with bone graft, porous tantalum rod insertion shows more satisfactory result in the joint function improvement following avascular necrosis of the femoral head at early stage, and prevents the continuous sinking of joint cartilage. Related Articles | Metrics

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Clinical application and follow-up of new-type HD soft hydrophilic contact lenses Gan Jin-hua, Zhang Jun, Lü Hong-bin 2012, 16 (29):  5506-5510.  doi: 10.3969/j.issn. 2095-4344.2012.29. 039 Abstract ( 232 )   PDF (430KB) ( 439 )   Save BACKGROUND: The wear of soft hydrophilic contact lens is a method of correcting refractive errors. But the safety and comfort of its clinical application is not definite enough. OBJECTIVE: To investigate the clinical effects and safety of a new type of HD soft hydrophilic contact lenses in comparison with the similar products-NB soft hydrophilic contact lenses that have been listed. METHODS: Seventy-two patients (144 eyes) had the same refractive state of eyes, and the diopter was 0 m-1 to -8.00 m-1. Ametropia patients whose cylinder degree of the better eyes was ≤ -1.00 m-1 were randomly divided into experimental group (wearing HD soft hydrophilic contact lenses) and control group (wearing NB soft hydrophilic contact lens) for vision correction. RESULTS AND CONCLUSION: After treatment for 1 week, 1 month and 3 months, there were no significant differences between the experimental group and control group (P > 0.05). These findings suggest that the new-type HD soft hydrophilic contact lenses are safe and effective. Related Articles | Metrics