Seawater activated TiO2 photocatalyst for degradation of organic compounds

The world's oceans are polluted by a continuous inflow of plastic. Plastic fragments finally into microplastic, which can be taken up, for example by plankton, and subsequently by the entire ocean food web. An approach to reduce plastic pollution constitutes the accelerated microplastic degradation in marine environments. TiO₂ (anatase) is commonly used as an oxidative photocatalyst and well known to catalyze the degradation of organic compounds upon UV irradiation.In this study, a selective activation of TiO₂ (anatase) particles encapsulated by Ca- or Sr-polyphosphate is presented. The TiO₂ polyphosphate core-shell particles are envisaged as additives in plastic products. The highly concentrated cations from seawater, viz. Na⁺ and Mg²⁺, displace the Ca²⁺ or Sr²⁺ cations from the polyphosphate shell. As a result, the polyphosphate coating dissolves and thus the photocatalytically active TiO₂ core is released. The stability of the TiO₂ polyphosphate particles in potable water and the seawater activated disintegration of methylene blue, methyl methacrylate, terephtalic acid, and poly(vinyl alcohol) was shown. It has been demonstrated, that the sweetwater stable polyphosphate coating degrades in the presence of seawater, which could be monitored by the activation of the TiO₂ (anatase) photocatalyst.     

Biomechanical investigation of maxillary implant-supported full-arch prostheses produced with different framework materials: a finite elements study

PURPOSEFour and six implant-supported fixed full-arch prostheses with various framework materials were assessed under different loading conditions.MATERIALS AND METHODSIn the edentulous maxilla, the implants were positioned in a configuration of four to six implant modalities. CoCr, Ti, ZrO₂, and PEEK materials were used to produce the prosthetic structure. Using finite element stress analysis, the first molar was subjected to a 200 N axial and 45° oblique force. Stresses were measured on the bone, implants, abutment screw, abutment, and prosthetic screw. The Von Mises, maximum, and minimum principal stress values were calculated and compared.RESULTSThe maximum and minimum principal stresses in bone were determined as CoCr < ZrO₂ < Ti < PEEK. The Von Mises stresses on the implant, implant screw, abutment, and prosthetic screws were determined as CoCr < ZrO₂ < Ti < PEEK. The highest Von Mises stress was 9584.4 Mpa in PEEK material on the prosthetic screw under 4 implant-oblique loading. The highest maximum principal stress value in bone was found to be 120.89 Mpa, for PEEK in 4 implant-oblique loading.CONCLUSIONFor four and six implant-supported structures, and depending on the loading condition, the system accumulated different stresses. The distribution of stress was reduced in materials with a high elastic modulus. When choosing materials for implant-supported fixed prostheses, it is essential to consider both the number of implants and the mechanical and physical attributes of the framework material.     

微型金属钛板内固定在下颌骨骨折中的应用

目的　总结分析微型钛板在下颌骨骨折中的应用特点。方法　对 2 5例各种类型的下颌骨骨折采用微型钛板手术内固定。结果　所有病例骨折对位良好 ,骨愈合正常 ,有 1例钛螺钉松动而取出钛板。结论　微型钛板坚固内固定适用于各种下颌骨骨折 ,只要手术时处置得当 ,疗效令人满意。     

口内切口与牵引钉暂时颌间刚性牵引固定治疗下颌骨骨折45例分析

目的:评价术中利用颌间牵引螺丝暂时牵引,经口内切口进行整复并坚强内固定治疗45例下颌骨骨折的效果。方法:对45例54处下颌体及下颌角区线性骨折,先分别在上、下颌中切牙之间、尖牙与第一前磨牙之间、第一与第二磨牙之间的根向植入颌间牵引螺丝,骨折复位后,进行颌间结扎固定,恢复咬合关系及下颌骨的弓型。自下颌前庭沟、翼下颌皱襞切开黏骨膜,显露骨折处并复位后,在张力线上用小型钛板进行坚强内固定术。术毕拆除颌间结扎,7d后将颌间牵引螺丝拆除。分别于术后第1天和第90天进行临床和X线检查,评价其咬合关系、骨折复位及愈合情况。结果:45例54处下颌骨骨折均获得良好的复位和骨性愈合,咬合关系良好,无明显并发症。结论:经口内途径行小型钛板坚强内固定术,结合颌间牵引螺丝暂时刚性牵引结扎,对下颌体及下颌角骨折的整复固定和功能恢复效果良好。     

后路cage椎体间植骨融合术在下腰椎融合的应用

目的 探讨后路cage椎间植骨融合术治疗下腰椎疾病的应用价值。方法 运用后路cage椎间植骨融合术治疗腰椎间盘突出症10例,单纯腰椎滑脱症11例,腰椎管狭窄症3例,腰椎狭部不连2例。结果 术后经6。12个月随访,临床疗效优良率92．3％(优80．8％,良11．5％),植骨融合率96％,短时神经功能障碍1例。结论 后路cage椎间植骨融合术是治疗下腰椎不稳或滑脱的有效方法,临床疗效满意。     

钛网植骨联合颈前路钢板内固定术治疗颈椎病的临床护理

颈前路减压植骨融合术已广泛应用于颈椎伤病的手术治疗,并取得了显著疗效.但由于需要取自体髂骨,供骨区感染、骨折、慢性疼痛等并发症的发病率高达10％～30％[1-2].我院2007年5月～2010年5月应用钛网植骨联合颈前路钢板内固定治疗颈椎病32例,取得了满意的效果,现将我们对该手术的临床护理总结如下.     

Influence of Oxynitrided Surface in the Production of a Less Susceptible Titanium Surface to Skin‐Borne Bacterial Adhesion

There is a growing quest for an ideal biomaterial that shows appropriate cellular response and is not susceptible to microbial adhesion. In this study, commercial grade II titanium was submitted to RF/DC plasma surface modification at 2.2 mbar, using gas mixtures of argon, nitrogen, and oxygen at proportions 4:1:2 and 4:1:3. The surfaces were physically and chemically characterized. In order to evaluate bacterial response, the surfaces were exposed to Staphylococcus epidermidis. Oxynitrided samples, although having a higher roughness as compared with untreated samples, exhibited lower bacterial growth. This observation is probably due to the formation of different crystalline phases of nitrides and oxides caused by plasma treatment. The surface with highest contact angle and highest surface tension showed lower bacterial adhesion. These results were confirmed by scanning electron microscopy. The role of nitrogen in reducing bacterial adhesion is clear when this material is compared with untreated titanium, on which only an oxide film is present.     

钛板内固定联合正畸技术在治疗陈旧性颌面骨折中的应用

目的探讨微型钛板内固定联合正畸技术在陈旧性颌骨骨折中的应用。方法对45例陈旧性颌面骨折患者采取术前行螺旋CT扫描及三维重建明确骨折部位及程度,经手术切开复位并行微型钛板内固定,术后进行正畸治疗,随访观察治疗效果。结果45例患者经4～18个月的随访,双侧颜面部对称,张口度正常,咬合关系恢复。结论手术复位后采取微型钛板内固定联合正畸技术治疗陈旧性颌骨骨折可获得满意效果。     

医用钛缆环扎加"8"字张力带内固定在髌骨骨折治疗中的应用

目的 探讨医用钛缆张力带在髌骨骨折中的应用价值.方法 2009年10月至2012年12月102例髌骨骨折,均遵循张力带原则,行环扎加"8"字张力带内固定术治疗,根据内固定材料分成医用钛缆组和带针钢丝组.比较两组术后首次锻炼时间、住院时间、医疗费用、并发症及远期膝关节功能情况.结果 102例患者术后随访10周~8个月,末次随访时骨折均达骨性愈合标准.两组患者在术后首次锻炼时间、住院时间方面无明显差异.医用钛缆组费用较高.医用钛缆组在并发症及远期膝关节功能上优于带针钢丝组.结论 医用钛缆在行张力带内固定治疗髌骨骨折具有内固定坚强、便于术后早期功能锻炼,弥补带针钢丝内固定强度不足的缺点.     

关节镜辅助下髓芯减压植入复合自体骨髓的骨诱导材料联合钛棒支撑治疗Ⅱ期股骨头坏死

目的评估微创经皮关节镜辅助下髓芯减压植入复合自体骨髓的骨诱导材料联合钛棒支撑治疗Ⅱ期股骨头坏死可行性和临床疗效。方法将2003～2007年确诊的股骨头坏死国际骨科循环学会(ARCO)分期Ⅱ期38例46髋,Ⅱa期10髋、Ⅱb期22髋、Ⅱc期14髋;在C型臂透视定位及关节镜辅助下,经皮微创有效准确地进行髓芯减压,对髋关节腔内和股骨头内病变组织清除彻底,改善股骨头内外环境,植入复合自体骨髓的骨诱导材料,并用钛棒支撑股骨头软骨下骨质。术后6、12、24、36个月进行随诊,以Harris髋关节评分、X线片观察病变分期稳定性及临床疗效为评价指标。治疗前后比较采用Student成组设计Dunnett-t检验。结果术后除24个月这个时间段与12个月时相比较,评分指数改善不明显外,术后其余各时间段之间前后比较及与相对应的术前比较,差异均有统计学意义(P<0.05);手术前后X线分期比较,术后16～24个月有4例Ⅱb期进展为Ⅱc期,其中2例以后未恶化,另2例由Ⅱc期进展为Ⅲ期;原始Ⅱc期有2例髋术后24个月病变开始进展,股骨头塌陷,30个月后行全髋关节置换术(THA);术后总改善率为80.43%,Ⅱa期病变治疗改善最好(90%)...