Electrochemical aspects of the formation of Bi2Te3 thin film via the route of ECALE

A Bi₂Te₃ VA–VIA group compound thin film was prepared via the route of electrochemical atomic layer epitaxy in this paper. The dependence of thin film formation on the electrochemical conditions (such as deposition potential control, supporting electrolyte and substrate) was studied, and the formation process of Bi₂Te₃ film was determined. The results show that Bi upd on Pt occurs at more negative potential in a HNO₃ supporting electrolyte than in a HClO₄ supporting electrolyte, and the Te upd peak moves to a more negative potential in HClO₄ supporting electrolyte solution than that in HNO₃ solution; Both Te and Bi upd on an Ag substrate occur at more negative potentials than that on a Pt substrate. In order to reach steady state deposition, a potential adjustment is necessary for the first 30 or more cycles of each component. After deposition of this initial ‘buffer layer’, the potentials can be kept constant for the remaining cycles. The effect of the slope of the shift of potential used to deposit the first 30 atomic layers of Bi and Te on the deposit has also been investigated. The deposit exhibits a two phase mixture of excess elemental Bi and Bi₂Te₃ compound when the slope is larger than ?4 mV/p (p indicates per cycle); a single-phase Bi₂Te₃ compound was obtained at a slope of ?6 mV/p, and Bi₄Te₃ compound also appears in the deposit along with Bi₂Te₃ when the slope is decreased to a more negative value of ?10 mV/p.     

带控制阀种植牙手术骨粉收集器的研制及临床应用

目的 介绍自行研制的带控制阀种植牙手术骨粉收集器,并观察其临床应用效果.方法 选取2008年5月至2009年10月38例牙种植患者,应用自制的骨粉收集器收集种植窝制备时产生的骨碎屑,并将其用于修复种植体周围骨缺损,其中开窗式骨缺损29处,唇颊(舌)侧种植体颈部角形缺损23处.结果 所有病例术后均无创口感染及裂开,原缺损处局部形态饱满,牙龈无明显退缩,X线片示种植体与周围牙槽骨形成良好的骨结合.结论 应用自制骨粉收集器收集的骨粉修复种植体周围小型骨缺损效果良好,使用方便,具有良好的应用前景.

Abstract：

Objective To introduce a self-developed bone collector designed by the authors and evaluate its effect in clinical application. Methods A self-developed bone collector was used in 38 patients who underwent the dental implant operation from May 2008 to October 2009. During the operation the bone particles were harvested, which was used for the reconstruction of the bone defects around the implant simultaneously. The defects were fenestrate in 29 regions and triangle in 23 regions on buccal or lingual side of the dental implants. Results All cases had no surgical wound infection and dehiscence 7-10 days after operation. Three to six months after implantation, the X-ray showed that all the dental implants had perfect osseointergration and the alveolar bone were successfully augmented. Conclusions Bone debris harvested by self-developed bone collector could repair small peri-implant bone defects, which is simple to use in clinic.     

Evidence of chemisorption of maleic acid to enamel and hydroxyapatite

Maleic acid has been used as an etchant or non-rinse conditioner in adhesive dentistry. However, the inherent mechanisms of the interaction of maleic acid with hydroxyapatite/enamel have never been fully elucidated. The purpose of this study was to provide evidence for the chemisorption of maleic acid onto hydroxyapatite/enamel, and to identify the reaction products obtained following the interaction of maleic acid with hydroxyapatite. Hydroxyapatite particles were dissolved in a 15% (w/v) aqueous solution of maleic acid (pH = 0.98). Half of the solution was dried to obtain a desiccated mixture. This mixture, hydroxyapatite, maleic acid and self-prepared calcium maleate were analysed by X-ray diffraction (XRD). Acetone was added to the other half of the solution to obtain a precipitate. This precipitate, hydroxyapatite, maleic acid, unetched enamel and maleic acid-etched enamel were analysed by X-ray photoelectron spectroscopy (XPS). The precipitate was also analysed by (1)H NMR. A new binding energy, indicating carboxylate groups, was detected by XPS on the precipitate and maleic acid-etched enamel surface. XRD data indicated the formation of calcium maleate and calcium hydrogen phosphate after the reaction. NMR data revealed that one carboxylic group of maleic acid reacted with hydroxyapatite. Hence, maleic acid can chemisorb to hydroxyapatite and enamel via ionic interactions.     

Tip-Edge Plus矫治器矫治慢性牙周炎致错(牙合)畸形的疗程观察

目的 比较3种矫治器矫治慢性牙周炎致前牙病理性移位患者的疗程.方法将60例慢性牙周炎致前牙病理性移位的患者分为3组(每组20个人),分别应用3种矫治技术进行矫治,并对3组患者的疗程进行统计学分析. 结果应用固定矫治器矫治,牙周状态评估指数为预后极佳;疗程在3组有显著性差异(F=130.67,P=0.0001), Tip-Edge Plus组疗程最短,平均缩短5.6个月,具有统计学意义.结论 Tip-Edge Plus矫治器矫治效果好,病程短,明显优于其它两种矫治器的矫治,更适合牙周炎致错(牙合)畸形的矫治.     

Antimicrobial effect of triclosan and triclosan with Gantrez on five common endodontic pathogens

Microbial control of the root canal system is one of the key objectives of root canal therapy. Triclosan is a widely accepted broad spectrum antimicrobial agent proven to be effective against many gram-positive and gram-negative bacteria. Triclosan acts by blocking bacterial fatty acid biosynthesis. The addition of Gantrez copolymer has been shown to enhance the antimicrobial activity of triclosan. The purpose of this study was to determine the minimum inhibitory and bactericidal concentrations of triclosan and triclosan with Gantrez against Prevotella intermedia, Fusobacterium nucleatum, Actinomyces naeslundii, Porphyromonas gingivalis, and Enterococcus faecalis. The minimum inhibitory concentration (MIC) of both test solutions was determined for each of the 5 microorganisms by using microtiter serial dilutions. Samples were streaked on 5% sheep blood agar plates and placed in an anaerobic incubator to determine the minimum bactericidal concentration (MBC). The MBC of triclosan ranged from 12-94 microg/mL. The MBC of triclosan with Gantrez ranged from <0.3-10.4 microg/mL. The addition of Gantrez enhanced the bactericidal activity of triclosan. Both triclosan and triclosan with Gantrez demonstrated bactericidal activity against the 5 specific endodontic pathogens.     

常用根管充填材料生物相容性研究

通过细胞附着实验和扫描电镜技术对四种常用根管封闭剂以及三种牙胶尖的生物相容性研究发现：所有充填材料甚至一直被 认为细胞毒性最小的牙胶尖均有明显的细胞毒性。因此，在临床上，为了避免材料对根尖周细胞产生机械刺激和减少细胞毒性作用，应尽量避免根管充填材料超填。本文还就氯仿是否可用于根管治疗进行了讨论。     

冠状切口在颧骨复合体骨折中的应用

目的探讨颧骨复合体骨折复位和固定术中应用冠状切口入路的手术适应证、手术方法及减少并发症的措施。方法84例颧骨复合体骨折的患者应用单纯冠状切口为36.9%、冠状切口 下睑缘切口为32.1%、冠状切口 下睑缘切口 前庭沟切口为16.7%和冠状切口 前庭沟切口为14.3%。术中患者均使用微型钛板或小型钛板坚强内固定。对于眶底骨折出现眼球内陷的患者以羟基磷灰石人工骨进行眶底重建。结果84例患者均未发生手术后切口感染,术后随访3个月到2年,无面神经永久性损伤,术后所有咬合关系紊乱的患者均达到功能性咬合。通过训练后张口度得到满意恢复。8例患者术后患侧颧弓处仍稍显膨隆。术后眼球内陷只有1例仍大于3mm,其余均恢复满意。结论颧骨复合体骨折使用头皮冠状切口时,熟练掌握颞部的解剖层次是至关重要的,仔细保护神经及血管结构可减少手术并发症。     

舌大小二维超声成像测量分析方法的建立及其评价

目的：建立一种舌大小测量分析方法，为舌大小在错He发病中的作用研究奠定基础。方法：采用B超超声像方法取舌正中纵断面和横切面图像，选取代表舌大小的参数进行测量，从而分析舌大小。结果：通过对测量结果的可重复性和准确性检验。认为这一测量方法是准确可行的，结论：建立的舌大濒分析方法可以作为研究手段使用。     

Effect of smear layer and direction of dentinal tubules on osteoblast adhesion to human dentin tissue

The purpose of this study was to investigate the effect of smear layer and direction of dentinal tubules on osteoblast adhesion to human dentin tissue in vitro. Dentin disks were made from human premolars extracted for orthodontic reasons. Dentin disks were cut either perpendicularly to the long axis of the tooth or at 45 degrees to the long axis of tooth. The smear layer was removed by 34% phosphoric acid gel from half of the dentin disk surface. Human osteoblast-like Saos-2 cells were grown in RPMI medium with 10% fetal bovine serum and 1% antibiotic/antimycotic cocktail under standard cell culture conditions. Cells were seeded into Nunc four-well culture plates at 1.5 x 10(5) cells per well with dentin disks in the bottom of each well. After 1 day in culture the dentin disks along with cells grown on their surface were examined with a scanning electron microscopy. Osteoblasts attached and spread on the dentin surface and formed a monolayer in the presence and absence of a smear layer. Cells spread over the dentinal tubules despite their direction. These results suggest that cell adhesion and spreading of osteoblasts is not influenced either by the existence of a smear layer or the direction of the dentinal tubules on the dentin surface.     

Short-term fluoride release from various aesthetic restorative materials

The short-term fluoride release of a giomer (Reactmer), a compomer (Dyract AP), a conventional glass ionomer cement (Fuji II Cap) and a resin-modified glass ionomer cement (Fuji II LC) was evaluated and compared. Specimen discs (6 +/-0.2 mm diameter and 1 +/- 0.2 mm thick) were prepared for each material using custom molds. Each disc was placed in 1 ml of deionized for 24 hours at 37 degrees C. After one day, the water was extracted and analyzed. The specimen discs were then re-immersed into another 1 ml of fresh deionized water. The procedure of removing and refilling the water was repeated for 28 days. Sample solutions taken during the first seven days and at days 14, 21 and 28 were introduced into a capillary electrophoresis system using field amplified sample injection (FASI) to determine fluoride release. Data was analyzed using factorial ANOVA/Scheffe's post-hoc test at significance level 0.05. An initial fluoride "burst" effect was observed with glass ionomers. Both compomer and giomer did not show an initial fluoride "burst" effect. With the exception of the compomer, fluoride release at day one was generally significantly greater than at the other time intervals. The glass ionomers released significantly more fluoride than the compomer and giomer at day one. Although fluoride release of the giomer was significantly greater than the other materials at day seven, it became significantly lower at day 28.