IPS e.max Press铸瓷与合金嵌体治疗后牙牙体缺损效果对比研究

目的探讨IPS e.max Press铸瓷与合金嵌体治疗后牙牙体缺损的效果。方法前瞻性纳入2020-05—2022-05三门峡市中心医院口腔科收治的后牙牙体缺损患者,根据修复材料分为IPS e.max Press铸瓷嵌体组(铸瓷组)和合金嵌体组(合金组)。比较2组患者的基线资料。治疗前后检测患者的龈沟液中炎性因子、评价牙周健康情况。治疗3个月后评价牙体缺损边缘密合度和美牙效果。结果共纳入86例(132颗牙)患者,每组43例(66颗牙)。2组患者的基线资料差异无统计学意义(P>0.05)。治疗后铸瓷组患者的IL-6、IL-8、CXCL16水平和GI、SBI及PLI评分均低于合金组;牙体缺损边缘密合度优于合金组,美牙效果满意率高于合金组。差异均有统计学意义(P<0.05)。结论与合金嵌体比较,采用IPS e.max Press铸瓷嵌体治疗后牙牙体缺损有利于降低龈沟液中炎性因子水平,改善牙周健康状况和牙体缺损边缘密合度,并可提高患者对美牙效果的满意度。但仍需进行更大样本量的前瞻性随机对照研究予以证实。

IPS e.max press热压铸造陶瓷全冠及二氧化锆全瓷冠对前牙修复患者牙龈健康美观度的影响

目的:比较IPS e.max press热压铸造陶瓷全冠及二氧化锆全瓷冠对前牙修复患者牙龈健康、美观度的影响,为前牙美学修复的材料选择提供临床参考。方法:以2021年5月至2022年5月于我院接受前牙修复的104例患者为研究对象,以随机数字表法分为两组,分别52例。观察组、对照组分别以IPS e.max press铸瓷全冠、二氧化锆全瓷冠修复,比较两组患者的临床修复效果及修复后的牙龈指数、菌斑指数、龈沟出血指数、龈沟液炎性因子水平。结果:观察组边缘密合度、继发龋情况均优于对照组(P<0.05);修复后,观察组牙龈指数、菌斑指数等显著小于对照组,龈沟液IL-6、IL-8及TNF-α水平显著低于对照组(P<0.05);修复12个月后,观察组PES评分高于对照组(P<0.05)。结论:相比于二氧化锆全瓷冠,IPS e.max press铸瓷全冠具有良好的前牙美学修复效果,可降低龈沟液炎性因子水平,改善牙龈健康,并能提高前牙美观度。

Gas encapsulation technology for large volume press

For samples in the gaseous state at room temperature and ambient pressure,mature technology has been developed to encapsulate them in a diamond anvil cell(DAC).However,the large volume press(LVP)can only treat samples with starting materials in solid or liquid form.We have achieved stable encapsulation and reaction treatment of carbon dioxide in a centimeter sized sample chamber for a long time(over 10 min)under conditions of temperature higher than 1200C and pressure over 5 GPa through the use of integrated low-temperature freezing and rapid compression sealing method for LVP cell assemblies.This technology can also be applied to the packaging of other gaseous or liquid samples,such as ammonia,sulfur dioxide,water,etc.in LVP devices.

Electrospinning-hot pressing technique for the fabrication of thermal and electrical storage membranes and its applications

The combination of electrospinning and hot pressing,namely the electrospinning-hot pressing technique(EHPT),is an efficient and convenient method for preparing nanofibrous composite materials with good energy storage performance.The emerging composite membrane prepared by EHPT,which exhibits the advantages of large surface area,controllable morphology,and compact structure,has attracted immense attention.In this paper,the conduction mechanism of composite membranes in thermal and electrical energy storage and the performance enhancement method based on the fabrication process of EHPT are systematically discussed.Moreover,the state-of-the-art applications of composite membranes in these two fields are introduced.In particular,in the field of thermal energy storage,EHPT-prepared membranes have longitudinal and transverse nanofibers,which generate unique thermal conductivity pathways;also,these nanofibers offer enough space for the filling of functional materials.Moreover,EHPT-prepared membranes are beneficial in thermal management systems,building energy conservation,and electrical energy storage,e.g.,improving the electrochemical properties of the separators as well as their mechanical and thermal stability.The application of electrospinning-hot pressing membranes on capacitors,lithium-ion batteries(LIBs),fuel cells,sodium-ion batteries(SIBs),and hydrogen bromine flow batteries(HBFBs)still requires examination.In the future,EHPT is expected to make the field more exciting through its own technological breakthroughs or be combined with other technologies to produce intelligent materials.

Influence of Formulation and Hot-Pressing Conditions on the Performance of Bio-Based Molasses Adhesive for Plywood

Molasses can serve as a natural adhesive for plywood and particleboard.However,several disadvantages remain,including lower dimensional stability and low bonding strength compared to other adhesives.Therefore,modifications are needed to use molasses as an adhesive for plywood.This research aims to improve bio-based molasses(MO)adhesive for plywood using citric acid(CA)adhesive.In addition,this research aims to analyze the effect of adding citric acid and to investigate the optimum hot-pressing temperature to produce the best quality plywood.In the first stage,the molasses and citric acid were combined in a ratio of 100:0,75:25,50:50,25:75,0:100 w/w%.Then,the second stage focuses on analyzing the influences of pressing temperature based on an optimum first stage.The research demonstrated that the addition of CA altered the gelation time,solid content,viscosity,and pH of the molasses adhesives.In addition,the thermal properties of molasses adhesives were changed after mixing with citric acid.These phenomena indicate changes in characteristics,such as the curing of adhesive.Overall,the characteristics of plywood showed a steady improvement as the CA ratio increased but revealed a significant decline for the 25:75 MO-CA ratio.By raising the pressing temperature from 180℃ to 200℃,the quality of plywood was effectively improved.The plywood that was bonded using adhesives with a 50:50 MO-CA ratio exhibited superior mechanical properties and improved dimensional stability compared to the plywood bonded solely with MO.Furthermore,the optimal mechanical and physical properties resulted in plywood bonded with a 50:50 MO-CA ratio when subjected to a pressing temperature of 200℃.The Thermal and FTIR measurements revealed that CA established ester bonds with both the MO and wood veneers.In conclusion,the mechanical characteristics of plywood were improved,while maintaining its excellent dimensional stability.

Ultrahigh strength and improved electrical conductivity in an aging strengthened copper alloy processed by combination of equal channel angular pressing and thermomechanical treatment

In this paper,equal channel angular pressing and thermomechanical treatment was employed to improve the strength and electrical conductivity of an aging strengthened Cu-Ti-Cr-Mg alloy,and the microstructure and properties of the alloy were investigated in detail.The results showed that the samples deformed by the combination of cryogenic equal channel angular pressing(ECAP)and rolling had good comprehensive properties after aging at 400℃.The tensile strength of the peak-aged and over-aged samples was 1120 MPa and 940 MPa,with their corresponding electrical conductivity of 14.7%IACS and 22.1%IACS,respectively.ECAP and cryogenic rolling introduced high density dislocations,leading to the inhibition of the softening effects and refinement of the grains.After a long time aging at 400℃,the alloy exhibited ultra-high strength with obvious increasing electrical conductivity.The high strength was attributed to the synergistic effect of work hardening,grain refinement strengthening and precipitation strengthening.The precipitation of a large amount of Ti atoms from the matrix led to the high electrical conductivity of the over-aged sample.

Chemical Composition of Pineapple Press Residues (Ananas comosus) and Effect on Growth Performance of Rabbit (Oryctolagus cuniculus)

With a view to improving rabbit production performance, a trial on the chemical composition of pineapple press residue (Ananas comosus) and the effect of its incorporation in the ration on rabbit growth performance (Oryctolagus cuniculus) was carried out at the KUATE Cunicole Farm in Bandjoun, in Western Cameroon. To do this, 36 rabbits of the local breed, aged 53 days with an average weight of 1337 ± 119 g were distributed and randomly assigned to 3 experimental rations corresponding respectively to treatments or batches T0, T1 and T2. The animals in treatment T0 received a ration containing no pineapple press residue, while those in treatments T1 and T2 received a ration containing 20% and 40% pineapple press residue, respectively. These residues were dried and ground for chemical composition analysis. The feed served as well as refusals from the previous day were weighed each morning to assess feed intake. The animals were weighed every 7 days to assess weight performance. At the end of the trial which lasted 7 weeks, the animals were fasted for 24 hours, then sacrificed to evaluate carcass characteristics and the relative weights of some digestive organs. The results of this study showed that pineapple press residues had a high crude fiber content (19.2%) and energy (2500 Kcal/kg DM). Their incorporation had no significant effect on feed intake and feed conversion ratio. The average live weight, weight gain and average daily weight gain of the animals receiving the ration with 20% inclusion of pineapple press residue were comparable to those of the control group and significantly higher than those of animals fed with 40% inclusion of pineapple residue. The highest carcass yields were obtained with rabbits fed 20% pineapple press residue in their ration. The cost of feed for the production of a kilogram live weight of rabbit tends to decrease with the ration incorporated with 20% pineapple press residue. Pineapple press residues constitute a by-product that can be recycled and their incorporation at 20% can increase rabbit growth performance and reduce production costs.

Solid state recycling of Mg-Gd-Y-Zn-Zr alloy chips by isothermal sintering and equal channel angular pressing

The Mg-7Gd-4Y-2Zn-0.5Zr alloy chips were successfully recycled through isothermal sintering and equal channel angular pressing(ECAP).The mechanical properties and microstructure evolution of samples during the recycling process were studied in detail.The eutectic phases in the as-cast alloy transform into long period-stacking ordered(LPSO)phases after homogenization,which can improve the plasticity of the material.After isothermal sintering,the density of the sample is lower than that of the homogenized sample,and oxide films are formed adjacent to the bonding interface of the metal chips.Hence,the plasticity of the sintered sample is poor.Dense samples are fabricated after ECAP.Although the grains are not refined compared to the sintered sample,the microstructure becomes more uniform due to recrystallization.Fiber interdendritic LPSO phase and kinked 14H-LPSO phase are formed in the alloy due to the shear deformation during the ECAP process,which improves the strength and plasticity of the sample significantly.Furthermore,the basal texture is weakened due to the Bc route of the ECAP process,which can increase the Schmid factor of the basal slip system and improve the elongation of the sample.After 2 ECAP passes,the fully densified recycled billet shows superior mechanical properties with an ultimate tensile strength of 307.1 MPa and elongation of 11.1%.

Effect of hot isostatic pressure on the microstructure and tensile properties of γ'-strengthened superalloy fabricated through induction-assisted directed energy deposition

The microstructure characteristics and strengthening mechanism of Inconel738LC(IN-738LC) alloy prepared by using induction-assisted directed energy deposition(IDED) were elucidated through the investigation of samples subjected to IDED under 1050℃ preheating with and without hot isostatic pressing(HIP,1190℃,105 MPa,and 3 h).Results show that the as-deposited sample mainly consisted of epitaxial columnar crystals and inhomogeneously distributed γ’ phases in interdendritic and dendritic core regions.After HIP,grain morphology changed negligibly,whereas the size of the γ’ phase became increasingly even.After further heat treatment(HT,1070℃,2 h + 845℃,24 h),the γ’ phase in the as-deposited and HIPed samples presented a bimodal size distribution,whereas that in the as-deposited sample showed a size that remained uneven.The comparison of tensile properties revealed that the tensile strength and uniform elongation of the HIP + HTed sample increased by 5% and 46%,respectively,due to the synergistic deformation of bimodal γ’phases,especially large cubic γ’ phases.Finally,the relationship between phase transformations and plastic deformations in the IDEDed sample was discussed on the basis of generalized stability theory in terms of the trade-off between thermodynamics and kinetics.

Pressure generation under deformation in a large-volume press

Deformation can change the transition pathway of materials under high pressure,thus significantly affects physical and chemical properties of matters.However,accurate pressure calibration under deformation is challenging and thereby causes relatively large pressure uncertainties in deformation experiments,resulting in the synthesis of complex multiphase materials.Here,pressure generations of three types of deformation assemblies were well calibrated in a Walker-type largevolume press(LVP)by electrical resistance measurements combined with finite element simulations(FESs).Hard Al_(2)O_(3) or diamond pistons in shear and uniaxial deformation assemblies significantly increase the efficiency of pressure generation compared with the conventional quasi-hydrostatic assembly.The uniaxial deformation assembly using flat diamond pistons possesses the highest efficiency in these deformation assemblies.This finding is further confirmed by stress distribution analysis based on FESs.With this deformation assembly,we found shear can effectively promote the transformation of C60 into diamond under high pressure and realized the synthesis of phase-pure diamond at relatively moderate pressure and temperature conditions.The present developed techniques will help improve pressure efficiencies in LVP and explore the new physical and chemical properties of materials under deformation in both science and technology.

Improving mechanical properties and high-temperature oxidation of press hardened steel by adding Cr and Si

This work investigated the effect of Cr and Si on the mechanical properties and oxidation resistance of press hardened steel.Results indicated that the microstructure of the Cr-Si micro-alloyed press hardened steel consisted of lath martensite,M_(23)C_(6)carbides,and retained austenite.The retained austenite and carbides are responsible for the increase in elongation of the micro-alloyed steel.In addition,after oxidation at 930℃for 5 min,the thickness of the oxide scales on the Cr-Si micro-alloyed press hardened steel is less than 5μm,much thinner than 45.50μm-thick oxide scales on 22MnB5.The oxide scales of the Cr-Si micro-alloyed steel are composed of Fe_(2)O_(3),Fe_(3)O_(4),mixed spinel oxide(FeCr_(2)O_(4)and Fe_(2)SiO_(4)),and amorphous SiO_(2).Adding Cr and Si significantly reduces the thickness of the oxide scales and prevents the generation of the FeO phase.Due to the increase of spinel FeCr_(2)O_(4)and Fe_(2)SiO_(4)phase in the inner oxide scale and the amorphous SiO_(2)close to the substrate,the oxidation resistance of the Cr-Si micro-alloyed press hardened steel is improved.

Ballistic performance of titanium-based layered composites made using blended elemental powder metallurgy and hot isostatic pressing

Metal matrix composites tiles based on Ti-6Al-4V(Ti64)alloy,reinforced with 10,20,and 40(vol%)of either TiC or TiB particles were made using press-and-sinter blended elemental powder metallurgy(BEPM)and then bonded together into 3-layer laminated plates using hot isostatic pressing(HIP).The laminates were ballistically tested and demonstrated superior performance.The microstructure and properties of the laminates were analyzed to determine the effect of the BEPM and HIP processing on the ballistic properties of the layered plates.The effect of porosity in sintered composites on further diffusion bonding of the plates during HIP is analyzed to understand the bonding features at the interfaces between different adjacent layers in the laminate.Exceptional ballistic performance of fabricated structures was explained by a significant reduction in the residual porosity of the BEPM products by their additional processing using HIP,which provides an unprecedented increase in the hardness of the layered composites.It is argued that the combination of the used two technologies,BEPM and HIP is principally complimentary for the materials in question with the abilities to solve the essential problems of each used individually.

The Person Who Impressed Me Most

How time flies!I’m a little sad when I realize that I will graduate from junior high school in a few months.Luckily,I have some wonderful memories.The person who impressed me most was my friend.My English was bad before and I felt unhappy about it.So I told it to a girl called Mary,who was good at English.She was willing to help me and made friends with me.She taught me some useful ways to learn English.

The Thing that Impressed Me Most

Time flies like an arrow,and time lost never returns.In the past few years of my junior high school life,what impressed me most was running.At first,I didn’t like sports.I thought I was supposed to spend more time on school work than on exercise.But gradually,I found that running was not only good for my health,but also helped me relieve stress.When I opened my arms and stretched my legs on the playground,I was like a deer running in the field,which made me get a sense of belonging.

IPS e.max Press全瓷嵌体在后牙修复中的应用效果观察

目的:分析IPS e.max Press全瓷嵌体在后牙修复中的临床效果。方法:回顾性分析80例后牙修复患者临床资料,按照治疗方法不同分为对照组和观察组各40例。对照组采用氧化锆嵌体修复,观察组采用IPS e.max Press全瓷嵌体修复。比较两组修复效果、菌斑指数、咀嚼功能及患者满意度。结果:修复后半年观察组修复体完整性、边缘密合性、边缘变色、颜色匹配、继发龋评分分别为(0.43±0.08)分、(0.31±0.03)分、(0.49±0.06)分、(0.46±0.05)分和(1.05±0.07)分,低于对照组的(0.56±0.07)分、(0.47±0.05)分、(0.61±0.08)分、(0.58±0.06)分和(1.21±0.09)分,修复后3年观察组修复体完整性、边缘密合性、边缘变色、颜色匹配、继发龋评分分别为(0.51±0.05)分、(0.43±0.05)分、(0.61±0.07)分、(0.57±0.06)分和(0.91±0.04)分,低于对照组的(0.72±0.08)分、(0.65±0.07)分、(0.88±0.09)分、(0.72±0.08)分和(0.99±0.06)分,差异均有统计学意义(P<0.05)。修复后观察组菌斑指数(1.07±0.08)分,低于对照组的(1.71±0.09)分,修复后观察组咀嚼功能(95.46±3.41)%,优于对照组的(79.25±4.34)%,差异均有统计学意义(P<0.05)。观察组患者总满意率97.5%,高于对照组的80.0%,差异有统计学意义(P<0.05)。结论:IPS e.max Press全瓷嵌体修复后牙的临床效果优于氧化锆嵌体。

IPS e.max Press全瓷贴面在前牙修复中的应用

目的评价IPS e.max Press全瓷贴面在前牙美容修复应用中的临床疗效。方法对52例患者的103颗前牙进行IPS e.max Press全瓷贴面修复,于修复体粘接后每半年进行复查评价其临床效果。结果经过2年的复查,有1个瓷贴面发生折裂,2个出现裂纹,2颗贴面修复的基牙有轻度的牙龈炎症,无瓷贴面脱落。结论 IPS e.max Press全瓷贴面修复能有效保存牙体组织,获得满意的美学修复效果,在前牙美容修复中具有良好的应用前景。

STEAM和PRESS序列在脂肪肝定量诊断中应用价值的对比研究

目的比较STEAM和PRESS序列在脂肪肝定量诊断中的应用价值。方法选用45只健康新西兰大白兔,采用高脂高糖饲料加酒精饮料建立不同程度脂肪肝模型,采用STEAM和PRESS两种脉冲序列对同一位置、同一体素进行磁共振氢波谱扫描,共观察和测定9个指标,并逐一进行配对对照研究。结果经STEAM和PRESS两种定位方法测定,肝内水化学位移、脂肪化学位移、脂/水峰值比率、脂/水波峰下面积比率、脂肪百分比组间均数无显著性差异(P>0.05);而肝内水峰峰值、脂峰峰值、水波峰下面积、脂波峰下面积组间均数存在显著性差异(P<0.05),即STEAM序列下上述各指标均数明显低于PRESS序列,信号相对损失率平均约47.9%;且STEAM序列下各观测指标与脂肪肝病理分级的相关性普遍低于PRESS序列。结论PRESS较STEAM序列更适用于肝内脂肪含量的定量研究。

IPSe.max Press铸瓷嵌体修复后牙牙体缺损的临床效果评价

目的对后牙邻面洞采用IPSe.maxPress铸瓷嵌体修复后的临床观察和分析,评价铸瓷嵌体修复牙体缺损的临床效果.方法 36例患者制作IPSe.maxPress铸瓷嵌体36个,修复2 a后用改良瑞格(Ryge)标准评价方法,对瓷嵌体的各项临床指标:瓷表面质地、边缘适合性、颜色匹配、牙龈反应、术后敏感及存留率进行观察分析.结果 IPSe.maxPress铸瓷嵌体存2a存留率为92.7%;92%具有良好的边缘适合性;12.3%患者有牙龈探诊出血;17%的患者备牙后有冷热敏感症状,13.8%粘结后0.5 a内消失;100%的患者对颜色满意.结论 IPS e.max Press铸瓷嵌体是一种较为可靠、效果较好的后牙牙体缺损修复体.

氢氟酸和偶联剂的应用对e.max~ Press铸瓷与树脂水门汀黏结强度的影响

目的:观察酸蚀和偶联剂处理IPS e.max Press铸瓷对瓷与树脂水门汀黏结强度的影响。方法:将126个试件分为7组,分别以50g/L氢氟酸酸蚀0、10、20、30、60、120、180s后一半使用偶联剂,一半不使用偶联剂,与树脂水门汀黏结后测定剪切黏结强度,每组取2个试件进行扫描电镜观察。结果:仅酸蚀组的黏结强度最高可达33.98MPa(60s),对照组6.76MPa;单纯使用偶联剂可达22.23MPa,结合酸蚀最高可达35.16MPa(30s);扫描电镜可见酸蚀时间不同及是否使用偶联剂与瓷表面微观形貌有直接关系。结论:瓷酸蚀后配以偶联剂的使用可提高黏结强度,并可在较短时间就获得理想的黏结强度。

IPS e. max Press热压铸陶瓷的临床应用体会

目的探讨IPS e. max Press热压铸陶瓷的临床修复效果。方法采用IPS e. max Press热压铸陶瓷技术制作70例163件全瓷修复体,并进行一年多的随访。结果制作的163件全瓷修复体色泽自然,边缘密合,牙龈组织健康。随访一年多成功159件,失败4件,成功率为97.6%,其中1件为崩瓷,3件为粘接脱落。结论IPS e. max Press热压铸陶瓷具有良好的临床修复效果。