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Direct pulp capping induces a local inflammatory process. Several biomaterials have been used for this procedure. The aim of this study was to compare the dentinal bridge thickness using three different pulp capping biomaterials with the conventional technique (high speed diamond bur) or Er-Yag laser, 1 month after pulp effraction. Materials and Methods: Forty two Class V cavities were prepared on the buccal surface of 4 maxillary incisors and 2 mandibular incisors of New Zealand rabbits. Specimens were divided into 6 treatment groups. Teeth were treated with: In Group 1: Er-Yag laser and Biodentine® (Septodont), in Group 2: Er: Yag laser and calcium hydroxide (Dycal® Dentsply), in Group 3: Er: Yag laser and adhesive system (Prime& Bond® NT Dentsply), in Group 4: high speed diamond bur and Biodentine® (Septodont), in Group 5: high speed diamond bur and calcium hydroxide (Dycal® Dentsply), and in Group 6: high speed diamond bur and adhesive system (Prime& Bond® NT Dentsply). The preparation was done with copious irrigation. The animals were sacrificed at 30 days and the teeth were extracted and prepared for histological analysis. Results: In the group of « laser Er-Yag ¼, iatrogenic pulpal wounds treated with Biodentine® were covered with a thick hard tissue barrier after 1 month. The difference was not significant with the groups of Dycal® used with Er: Yag laser and high speed diamond bur. Prime& Bond® NT Dentsply specimens showed a thin dentinal bridge layer. Conclusion: At 1 month, Er-Yag laser proved to be useful with Biodentine® for direct pulp capping procedures
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Animals , Rabbits , Polymethacrylic Acids , Calcium Hydroxide , Silicates , Calcium Compounds , Dental Pulp Capping , Lasers, Solid-StateABSTRACT
Objective To investigate the clinical efficacy of tissue flap combined with antibiotic-loaded calcium sulfate and autogenous iliac bone grafting at stage Ⅰ for infected nonunion of long bone.Methods A retrospective case series study was conducted to analyze the clinical data of 51 patients with infected nonunion of long bones admitted to Tongde Hospital of Zhejiang Province from January 2013 to December2017.There were 42 males and nine females,aged 19-71 years,with an average age of 36.3 years.There were 43 patients with bone nonunion at tibia,six at femur,one at humerus,and one at ulna and radius.The range of bone defect area was 1-9 cm,with an average of 2.9 cm.On the basis of thorough debridement,tissue flaps combined with antibiotic-loaded calcium sulfate and autologous iliac bone graft were performed at stage Ⅰ treatment.The survival of skin flaps,infection control,nonunion healing and complications were recorded.Johner-Wruhs joint function assessment criteria were used to evaluate limb function.Results All patients were followed up for 10-35 months,with an average of 18.3 months.All flaps survived eventually.Except for one patient with infection recurrence,the other 50 patients with infection obtained primary cure.All nonunions were healed,with an average healing time of 6.4 months ranging from 4 to 15 months.Complications included venous crisis of skin flaps in five patients,anterolateral femoral cutaneous nerve injury in 20 patients,recurrence of infection in one patient,and infection of external fixator nail tract in three patients.Function evaluation results by Johner-Wruhs criteria were excellent in 34 patients,good in 14,and moderate in three patients,with an excellent and good rate of 94％.Conclusion On the basis of thorough debridement,tissue flap combined with antibiotic-loaded calcium sulfate and autogenous iliac bone graft can control the infection effectively,promote the bone union and improve the limb function.
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Objective To explore the possibility of polymethyl methacrylate (PMMA) bone cement as the carrier for lipophilic drugs through in vitro cytotoxicity study and molecular modeling with PMMA and 17-allylamino-17-demethoxy-geldanamycin (17-AAG) loaded PMMA bone cement.Methods The 17-AAG loaded bone cement was made by mixing method.In vitro antitumor activity with MTT assay for PMMA,17-AAG,the 24 h and 48 h released solution of 17-AAG loaded PMMA bone cement were evaluated.Through Material Studio 5.0,the interaction between 17-AAG and PMMA through the model of Amorphous Cell and energy optimization of Forcite was explored.Results The inhibition ratio of MMA for tumor cells is 9.21％±0.06％ with 50 μmol/L.The 24 h released solution of 17-AAG loaded PMMA bone cement (17-AAG∶ PMMA=1∶ 4 000) inhibits the tumor cells 66.15％±0.43％ which has a quick released influence on 17-AAG.The inhibition of 24 h released solution of 17-AAG-loaded PMMA bone cement (17-AAG∶PMMA=1 ∶ 1 000,1∶2 000) shows no significance compared with PMMA released solution (P＜0.05).The 48 h released solution of 17-AAG-PMMA (17-AAG∶ PMMA=1∶ 1 000,1∶2 000,1∶4 000) inhibits U26630.25％±4.47％,30.24％±3.42％,50.52％±5.20％,with a significant difference with PMMA.The molecular model showed that the interaction between 17-AAG and PMMA was van der Waalz bonds,which drove 17-AAG inside or on the surface of PMMA bone cement.Conclusion PMMA bone cement can be used as a carrier for lipophilic drugs.It has antitumor activity and influences the release of 17-AAG with different ratio,for example it has a sustained-released influence on 17-AAG in 17-AAG-PMMA (17-AAG∶PMMA=1 ∶ 1 000,1∶2 000).Molecular model implies that 17-AAG exists inside or on the surface the PMMA bone cement through van der Waalz bonds.
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Objective To determine the effect of high temperature denervation in back pain relief during percutaneous kyphoplasty (PKP) for vertebral osteoporotic fracture.Methods Fifty-six patients undergone PKP for single vertebral osteoporotic fracture were randomly divided into cooling group and normal group with 28 patients per group according to whether the temperature reducing measures were provided during the polymerization process of polymethyl methacrylate (PMMA).Data recorded were operation time, amount of PMMA injected into each vertebral body, visual analogue scale (VAS), Oswestry disability index (ODI), and anterior vertebral height.Results All the data revealed no significant differences between cooling and normal groups: operation time [(45.6 ± 7.3)min vs (43.6 ± 5.8)min], PMMA injected into each vertebral body [(2.8 ±0.3)ml vs (2.7 ±0.4)ml], VAS [(3.8 ± 0.7) points vs (3.2 ± 0.7) points], ODI [(36.6 ± 8.2) points vs (30.4 ± 6.0) points] and height restoration of anterior vertebral body [(85.3 ± 6.1)％ vs (83.9 ± 7.3)％] (P ＞ 0.05).Conclusion High temperature denervation contributes a little to the relief of back pain during PKP, as may be due to the vertebral augmentation and stabilization.
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Objective To evaluate the value of electrospun polymethyl methacrylate (PMMA) nanofibers with different topological structures as scaffolds for growth of Schwann cells (SCs).Methods Electrospun PMMA nanofibers with random or aligned topological structures were fabricated and measured with biocompatibility.Lentivirus-transfected green fluorescent protein was used as the reporting gene to monitor form and growth manner of SCs on different substrates and dependency of cell body and process with fiber structure,with PMMA thin films served as the control.Results Electrospun PMMA nanofibers revealed good biocompatibility and could exert contact guidance to the growth of SCs.Topological structures of the electrospun nanofibers influenced cell morphology.SCs were aligned with the orientation of substrate fibers and form longer cell process when growing on aligned nanofibers (P ＜0.01).Primary SCs preferred to follow the cue of aligned nanofibers compared to random fibers.Conclusion Aligned electrospun PMMA nanofibers have the potentiality as transplantable scaffolds for loading SCs after neural injury.
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BACKGROUND:Percutaneous vertebroplasty for vertebral fractures can effectively relieve acute pain and has the advantages of smal trauma, good curative effect and less complications, but for patients with osteoporotic compression fractures, there were varying degrees of osteoporosis after surgery, which have a longer course of disease and cannot be easy to cure. So the effectiveness of percutaneous vertebroplasty cannot be ful y evaluated based on the pain relief. OBJECTIVE:To study the curative effect of percutaneous vertebroplasty for patients with fresh osteoporotic thoracolumbar vertebral compression fractures. METHODS:We selected 24 patients undergoing percutaneous vertebroplasty and 24 patients receiving conservative treatment at the same time who had fresh osteoporotic compression fractures as research objects;and compared pain degree, vertebral body height and the kyphosis Cobb angle, function activity of the lower lumbar before and after treatment, the quality of life and clinical incidence of complications within 6 months after treatment in the two groups. RESULTS AND CONCLUSION:The degree of pain, the vertebral body height, kyphosis Cobb angle, function activity of the lower lumbar were al improved in the two groups after treatment (P<0.05), and these indexes in the percutaneous vertebroplasty group were better than those in the conservative treatment group (P<0.05). The quality of life and incidence of complications within 6 months after treatment were improved better in the percutaneous vertebroplasty group than the conservative treatment group (both P<0.05). These results suggest that the percutaneous vertebroplasty for fresh osteoporotic thoracolumbar vertebral compression fractures can effectively reduce the pain of patients, improve vertebral deformity and activities of the lower lumbar, and has obvious role in promoting the postoperative quality of life of patients.
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BACKGROUND:Screw loosening and shedding may occur after osteoporosis associated with lumbar degenerative disease treated with pedicle screw fixation. Application of pedicle screw enhanced with cured materials can improve the therapeutic effect. OBJECTIVE:To compare the clinical effect of pedicle screws enhanced with poly(methyl methacrylate) and injectable calcium sulfate cement in the lumbar internal fixation of osteoporosis. METHODS:Sixty-one patients diagnosed with osteoporosis combined with lumbar spondylolisthesis, lumbar spinal instability, and severe lumbar spinal stenosis were col ected. Al patients were divided into two groups according to the treatment method:poly(methyl methacrylate) bone cement enhanced pedicle screw group and calcium sulfate bone cement enhanced pedicle screw group. RESULTS AND CONCLUSION:There were no significant differences in the operation time, blood loss, preoperative and postoperative visual analog scale score, Japanese Orthopedic Association scores and the Japanese Orthopedic Association score improvement rate between two groups (P>0.05). The results showed that two patients had bone cement leakage in poly(methyl methacrylate) group which had no neurological symptoms caused by new symptoms during fol ow-up period. The bone mineral density was not improved gradual y in poly(methyl methacrylate) group with fol ow-up time prolonging;however, in calcium sulfate group, the bone mineral density was increased significantly after treatment, and the change of bone mineral density was linearly related with Japanese Orthopaedic Association score improvement rate in calcium sulfate group. No screw loosening, pul ing out or neurological dysfunction occurred in both groups. The results indicate that like poly(methyl methacrylate), balcium sulfate bone cement can increase the stability of pedicle screws.
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Objective To evaluate the efficacy of percutaneous vertebroplasty(PVP) using instruments and drugs made in China, and to provide the data for the clinical application Methods Polymethylmethacrylate(PMMA) without adding contrast was classified into 3 groups according to the ratio of powder/liquid as 2∶1,3∶2,1∶1,PMMA with contrast was also classified into 3 groups according to the ratio of powder/liquid/contrast as 2∶1∶1,3∶2∶1,1∶1∶1 There were 6 groups totally The periods and temperature of polymerizing process were measured The PMMA specimens of different group were made,with the diameter of 1 0 cm, height of 3 0 cm The density was determined in X ray pictures and mechanical testing with universal testing machine was performed PVPwas performed in the spines of 3 human cadavers with transpedicular route under fluoroscopic control The PMMA was injected into vertebra at an interval of one vertebra from T4-L4, 7 vertebra were injected on each cadaver The injected volume was recorded The spines were dissected into 42 single vertebrae, with all soft tissues removed Overall,21 pairs of adjacent vertebrae were subjected to axial compression in an universal testing machine The cranial vertebra of each pair was injected with PMMA, the caudal one served as a control Results Lower temperature was observed in the PMMA groups with adding contrast than those without adding contrast during the polymerizing process, the average temperature in the PMMA group with the ratio of powder/liquid/contrast as 3∶2∶1 was 67 4℃ There was significant X ray density difference between the groups with contrast and corresponding groups without contrast ( t = 20 00, t = 20 00, t = 22 86, P 0 05) The group with ratio of power/liquid/contrast 3∶2∶1 was (127? 4 70) s in the period of the paste, and the ultimate compressive strength (mPa) was 47 23 The punctures were successfully reached in all vertebra The injected PMMA average volume was 5 ml in the thoracic vertebra and 7 5 ml in the lumbar vertebra PMMA leaking into adjacent paravertebral tissue was demonstrated in 3 of 21 vertebrae The ultimate compressive strength of the vertebrae without PMMA injection in the 3 groups was 3 28,3 63,and 3 69, respectively The ultimate compressive strength of the injected PMMA vertebrae in the 3 groups was 4 52,4 73,and 4 81, respectively The ultimate compressive strength was significantly higher in the injected PMMA vertebrae than that in the vertebrae without PMMA injection( t =3 17,3 55,3 99, P
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Objective To evaluate the clinical value of vertebral body venography in performance of percutaneous vertebroplasty(PVP). Methods 92 patients with 124 vertebraes underwent PVP. Before injecting the bone cement, venography was performed with injection of nonionic contrast material into vertebral body. 124 vertebraes were classified into four groups according to the results of vebgrophy. Group A: no draining veins displayed; group B: draining veins appeared late; group C: draining veins appeared ahead of time; group D: draining veins appeared ahead of time, then intervention such as adjusting the puncture needle's position or gelatin sponge embolization of vein was performed to delay the appearance of veins. Results 94 of 124 vertebraes displayed draining veins. According to the results of vebgrophy, there're 30 vertebraes in group A, 25 in group B, 30 in group C, 39 in group D. Thirty-seven vertebraes demonstrated cement extravasation, cement entering vein was observed in sixteen vertebraes and two patients among them had pulmonary embolism. Venograms showed all correlative venous extravasation. Bone cement extravasation rate of each groups was 20.0%, 24.0%, 56.7% and 20.5% respectively. Moreover, extravasation rate of group C was higher than any other group. Pain reduction was observed in 88 of 92 patients after 30 days of the operation, the rate of pain relief was 95.7%. Conclusion Vertebral body venography could describe the velocity of venous blood flow within vertebral body and predict the direction of bone cement leaking to veins effectively, which could provid valuable information in takeing some measures to prevent bone cement leaking into veins. Vertebral body venography has very impotant clinical value in improving the safety and preventing complication of PVP.
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Objective To discuss the histology change,apoptosis state and Bcl-2,Bax expression after the bone cement leakage into the intervertebral disc in vertebroplasty.Methods Eight majority canis familiaris were studied.Three lumbar intervertebral discs(L2 to L5)in each dog were randomly classified into three groups(control group,PMMA group,and CPC group),the canine discs were stabbed by 18-gauge needle,and 0.1 ml cement was injected into them.Control discs were only stabbed and injected with nothing.Histology of all discs was studied 24 weeks after the operation.Terminal-deoxynucleotidyl transferase mediated nick end labeling(TUNEL)and immunohistochemisty were used to detect apoptosis and Bcl-2,Bax expression in the discs.The data were statistically analyzed by SPSS 12.0.Results Intervertebral disc degeneration was not found in control groups.In bone cement groups,however,ruptured or serpentine patterned fibers,decreased cellularity of the nucleus pulposus and condensed matrix of the nucleus pulposus were found in histologic results.The Bax protein decreased in the order of control group, CPC group,and PMMA group.However,the Bcl-2 protein increased in the order of control group,CPC group,and PMMA group.The histology grade was significantly different among the three groups under ANOVA analysis(P
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0.05), while the strength and stiffness were significantly different (P