Objective To explore the effect of different arch forms of maxillary models on stress distribution of peri-implant of All-on-4 implants with 3-dimensional finite element, and to provide evidence for the improvement of implant achievement ratio in clinic. Methods 3-dimensional finite element analysis models of Tapered,Square and Ovoid arch form maxillary based on the MBTTM Arch Form Templates were constructed by using Solidworks software.The cortical bone thickness was defined as 2 mm at all points.The implants with 13 mm in length were inserted between the mental foramina.The 2 posterior implants were set at 4 inclination angle,from 0°to 45°.All implants were splinted with superstructure.A 100 N pressure was applied to 2 kinds of loading positions on the superstructure models. The maximum Von-Mises stress on cortical bone around the implants was measured by using Abaqus software.Results The maximum Von-Mises value in maxillary cortical bone with All-on-4 implants in 3 arch forms showed significant differences. In Square model the concentration of stress was advanced with the increasing of implant inclination angle;In Ovoid model, the maximum Von-Mises value was observed at 1 5°in posterior region,and was increased significantly by pasted 15°in anterior region;In Tapered model,the Maximum Von-Mises value was increased greatly at 45°. Conclusion Arch forms have appreciable impact on stress distribution of peri-implant.In Square arch form,the inclination of implant should be avoided;in Ovoid arch form, the inclination angle should be under 15°;in Tapered arch form,the inclination should be under 30°.

OBJECTIVE： To observe the changes of insoluble particles of shuanghuanglian in quantity after mixed with benzylpenicillin,cefradine and dexamethasone in normal saline.METHODS： Using ZWF-4D particle counter,the number of insoluble particles in sizes of ≥ 2.0μ m,≥ 5.0μ m,≥ 10.0μ m and ≥ 25.0μ m was counted and compared before and after mixed with above-mentioned three drugs.RESULTS： The insoluble particles of Shuanghuanglian were obviously increased after mixed with benzylpenicillin,the particles in sizes of ≥ 5.0μ m,≥ 10.0μ m and ≥ 25.0μ m increased twice,23 and 94 times respectively.The insoluble particles were also increased after mixed with cefradine or dexamethasone,however,the increase rate was lower in comparison with that mixed with benzylpenicillin.CONCLUSION： Shuanghuanglian,used in combination with above-mentioned drugs,should be put into separate infusion bottle to avoid the increase of insoluble particles and ADRs.

Ionimplantationtechniqueisamethodthatprocessingthematerialsurfacesinordertochangetheirsurfacechemical,physical and mechanical properties in vacuum environment.Titanium and titanium alloys modified by different types of ions can change their surface properties and characteristics,thereby improving the osseointegration and antibacterial properties of titanium implant.This review summarizes the researches of titanium implant surface modified by different ions implanting.

0.05). The laser group with the dose of 3 J?cm-2 showed more increase in cell survival at 24 and 48 h after being seeded as compared with control group(P

OBJECTIVETo compare the accuracy of mesiodistal tooth angulation measurements by using traditional panoramic radiographs and cone beam CT (CBCT) panoramic images.

METHODSPlaster models of 15 volunteers with individual normal occlusions were collected. The functional occlusal plane and tooth long axis on the plaster models were marked from the right first molar to the left first molar in the upper and lower dental arches. A radiographic stent, which contains radiopaque markers near the functional occlusal plane and approximating the root axis, was fabricated for each model. Traditional panoramic radiographs and CBCT scan images were obtained from each patient, with the radiographic stent seated on the dentition. A panoramic image reconstruction was made from the CBCT volumetric data by using related software. The CBCT panoramic image data were oriented parallel to the maxillary or mandibular functional occlusal plane containing all the radiopaque markers when measuring the maxillary or mandibular teeth, respectively. The mesiodistal tooth angulations of the plaster model, traditional panoramic radiographs, and CBCT panoramic images were measured and compared. Multivariate analysis of variance and Dunnett-t test were performed to compare the differences among the three methods.

RESULTSThe difference among the three methods was statistically significant (P = 0.00). Significant differences compared with the model measurement were found in two teeth (upper second premolar and lower second premolar) among twelve teeth (P = 0.00) in traditional panoramic measurement. CBCT panoramic measurement was not significantly different to model measurement.

CONCLUSIONTraditional panoramic radiographs do not provide a more reliable measure of mesiodistal tooth angulation, whereas CBCT panoramic image is an tool for evaluating mesiodistal tooth angulation.

Bicuspid ; Cone-Beam Computed Tomography ; Dental Arch ; Dental Occlusion ; Humans ; Image Processing, Computer-Assisted ; Maxilla ; Molar ; Radiography, Panoramic ; Tooth ; Tooth Root

Objective; To investigate the stress distribution in implant-bone interface with different pitches by three-dimension finite element analysis method in order to decide the best design of thread parameters for stress distribution. Methods: Built three-dimension finite element models of partial mandible and dental implant with superstructure. The stress distributions in bone and three kinds of implants whose pitches were 0.6, 0.8 and 1.0 mm respectively, under axial and oblique 45 degree to axle concentrated load. Data were analyzed by Cosmos/works software. Results;The maximal Von-Mises stress, tensile stress and compressive stress of implant with 0.8 mm pitch were lower than others, the stress distribution was even. The stresses in the same model under oblique load were much higher than those under axial load. The stress concentrated more on implant neck, upper part of cortical bone and the lowest thread on implant. Conclusion; The pitch of implant has effect on stress distribution in implant-bone interface and the transmission of occlusal force. The lower threads on implant should be cut to avoid the concentration of stress, and the non-axial force should be reduced as possible as we can or avoided when we design and make implant denture.

BACKGROUND:There is often space between implant and bone during immediate implantation.Whether biological membrane is needed to guide bone regeneration remains poorly understood.OBJECTIVE:To createdifferent sizes of space between femurand implantsindogs and to observe the effects of biological membrane on bone regeneration capacity of bone defects surrounding implants.DESIGN,TIME AND SETTING:A self-control animal experiment was performed at the Laboratory Animal Center,Norman Bethune College of Medicine,Jilin University and School of Stomatology,Jilin University between March and December 2005.MATERIALS:BLB hydroxyapatite-coated implant was provided by Beijing Leiden Biomaterial Co.,Ltd.,China;BME-10X collagen membrane was purchased from Fujian Better Biotechnology Co..Ltd.,China.METHODS:BLB implants were installed in the bilateral proximal femoral bone to create standard gradient bone defects with horizontal width 3 mm.vertical depth 5 mm,and horizontal lengths of 0,1,2,3,and 4 mm Bone defects on the left femur were sutured directly and those on the right femur were covered with biological membrane prior to suture.All animals were sacrificed at 3 months after surgery.Specimens containing implants were harvested to prepare tissue blocks for radiological observation.MAIN OUTCOME MEASURES:The quantity,color,and texture of newly formed bone surrounding implants were observed from the surface and profile levels.The implant-bone integration and new bone formation were also examined by soft X-ray photography.RESULTS:Grossobservation results revealed that when the horizontal length of bone defect was 3 mm or less,there was no significant differenee in bone density between the newly formed bone and the host bone no matter whether biological membrane existed or not;when the horizontal length of bone defect was 4 mm the bone density was better when biological membranes were used than not.Soft X-ray photography results revealed that when the horizontal length ofbone defect was 3 mm or less.no significant difference in bone density and bone trabecular morphology and orientating was found between newly formed bone and host bone no matter whether biological membrane was used or not;in the 4-mm-length bone defect areas.implants contacted with newly formed bone directly,but the calcified degree ofnewly formed bone was poor,bone trabecula was thin,and bone trabecular course was irregular,nevertheless,the calcified degree of newly formed bone was better under the condition of being with biological membrane than without biological membrane.CONCLUSION:Biological membrane exhibits strong capacity to promote the regeneration and repair of bone defect tissue with a horizontal length of 3 mm or less,and plays an important role in repatr of large sizes of bone detect

Objective: To study the effects of hydrolysed casein in different doses on plasma and liver antioxidant capacities in mice. Methods: Fifty mice were divided into 5 groups: control group, vitamin E group (VE), low dose of hydrolysed casein group (CH1), medium dose of hydrolysed casein group(CH2)and high dose of hydrolysed casein group(CH3). The mice were supplemented with 0.25ml normal saline,7.2 mg/ml Vitamin E,4,12 and 20 mg/ml hydrolysed casein respectively by gavage one time a day. The mice were euthanatized after ten days. The activities of SOD, GSH-PX and the level of MDA were determined. Results: Hydrolysed casein in different dosese vidently increased the activities of SOD and GSH-Px in serum, and reduced the level of MDA in serum and liver of mice; group CH3 significantly increased the activities of GSH-Px in liver. Conclusion: Different doses of hydrolysed casein could raise plasma and liver antioxidant capacities in mice, especially the high dose of hydrolysed casein.

Objective:To observe the bone regeneration capacity of bone defects around BLB implants covered with or without membranes.Methods:Implants were installed into femoral bone of grown-up dogs.Near implants,3 mm horizontal width,5 mm vertical depth and 1,2,3,4 mm horizontal length(along the macroaxis of femoral bone) standard gradient bone defects were made.On one side,the incisions were directly sutured by lamination,and on the other side the incisions were sutured by lamination after using collagen membrane to cover on the defects.Three months after the operation the specimens were observed by stereomicroscopy.Results:In the groups with 1,2 and 3 mm defects,the defect areas had been filled completely with new bone which was mainly compact cortex.In the group with 4 mm defects,the defect areas were filled with new bone which was mainly trabecular bone.Bigger lacunes could be observed in the groups without membranes.Conclusion:If the defect is less than 3 mm,whether bioresorbable collagen membrane is used or not,osseointegration is well in the implant-bone interface.Improving bone regeneration should be done when the bone defect extension is bigger.

OBJECTIVE:To provide reference for clinical application of antibiotics and the management of pathogen. METH-ODS:The clinical isolated bacteria in our hospital from 2011 to 2014 were identified and analyzed,and the amount of antibiotics in our hospital from 2011 to 2014 were analyzed. The operation and result of drug susceptibility test were in accordance with the standard of clinical laboratory standards institute(CLSI),using WHONET software for statistical processing. RESULTS:The main bacteria isolated in our hospital during 2011-2014 were as follows:constituent ratio of Escherichia coli were 14.93%,16.81%, 15.01% and 15.41%,respectively;that of Staphylococcus aureus were 9.84%,11.90%,9.83% and 7.17%,respectively;that of Acinetobacter baumannii were 9.00%, 9.95%, 14.24% and 18.64%, respectively;that of Pseudomonas aeruginosa were 12.36%,12.42%,14.20% and 15.48%,respectively. The main antibiotics used in our hospital during 2011-2014 were as fol-lows:the amount of piperacillin/tazobactam(2.25 g/a)were 4 685,12 610,13 639 and 14 542,respectively;that of cefepime (0.5 g/a)were 8 613,24 738,12 684 and 6 751,respectively;that of aztreonam(0.5 g/a)were 14 124,32 062,3 323 and 4 534,respectively;that of meropenem(0.5 g/a)were 2 291,5 436,6 813 and 5 341,repectively;that of levofloxacin(0.3 g/a) were 12 253,40 893,48 468 and 50 558,respectively. CONCLUSIONS:With the increase of antibiotics,susceptibility rate of main pathogen are gradually decreased;rational use of antibiotics plays an important role in decreasing the drug resistance.