酸蚀对Dyract与牙齿密合度的影响

目的：评价酸蚀对Dyract与牙体硬组织之间密合度的影响。方法：离体牙制备成V类洞，经酸浊和未酸蚀处理，Dyract常规充填，应用扫描电镜观察。结果：低倍镜下，Dyract在使用和未使用酸蚀剂时均与牙釉质、牙本质之间的密合度良好；高倍镜下，Dyract在未使用酸蚀时，与牙釉质间的混合层内有时可见0．8－1．4μm的微缝隙；使用酸蚀剂后Dyract与牙釉质间的界面见充填材料与牙釉质直接粘结。无论酸蚀与否，Dyract与牙本质密合度好。结论：酸蚀剂的使用可改善Dyract与牙釉质之间的密合度。     

Nd：YAG激光对Dyract复合体充填微渗漏的影响

目的　观察Nd :YAG激光照射洞缘牙釉质对复合体Dyract充填微渗漏的影响。方法　新鲜拔除的完整离体牙 5 0颗 ,随机分为实验组 ( 2 6颗 )和对照组 ( 2 4颗 )。在样本牙的颊舌面制备V类洞 ,对照组常规完成Dyract充填 ,实验组用Nd :YAG激光照射洞缘牙釉质后再行Dyract充填。所有样本经冷热循环处理后 ,再进行微渗漏实验。用体视显微镜和SEM观察并拍照记录。结果　激光光蚀组充填体边缘微渗漏比对照组明显低 (P <0 .0 5 )。微渗漏实验与扫描电镜观察结果一致。结论　Nd :YAG激光的光蚀作用有助于增强复合体Dyract与牙体组织的结合 ,改善边缘封闭 ,减少微渗漏 ,有利于充填成功     

三种光固化材料充填后牙Ⅱ类龋洞的近期临床疗效观察

目的评价Dyract AP、可乐丽菲露AP-X、3M Z2503种光固化材料充填后牙Ⅱ类龋洞的近期疗效。方法收集200例患者350颗无牙髓病变、对He牙正常的患有Ⅱ类龋损的下颌第一或第二磨牙随机分组，分别采用Oyract AP、可乐丽菲露AP-X、3MZ250充填修复。临床追踪观察1年，评定其疗效。结果3组病例成功率分别为99．10％、98．58％、98．96％，经统计学处理其成功率之差异无显著意义。结论Oyract AP、可乐丽菲露AP-X、3MZ250充填后牙Ⅱ类龋洞的近期疗效均令人满意。     

排龈技术在牙体缺损修复中的应用

目的观察排龈对3MZ250复合树脂修复牙体缺损疗效的影响。方法选择31例120颗唇颊面牙颈部龋缺损牙,随机分为实验组和对照组,每组60颗,经窝洞预备后,实验组排龈线排龈后3MZ250复合树脂修复,对照组直接树脂修复,随访2年,评价修复体保存、继发龋以及边缘密合状况。结果充填后1周复查,使用排龈线组修复后悬突的发生率低于对照组,差异有显著性（P〈0．01）。充填后0．5年复查两组脱落率无明显差异;1年及2年后复查实验纽充填体的脱落率明显低于对照组（P〈0．05）。结论排龈可提高3MZ250复合树脂修复牙体缺损的修复体保存率,可以作为一项常规使用措施。     

酸蚀处理影响Dyract复合体修复楔状缺损的临床效果的研究

目的：采用改良的USPHS系统评估酸蚀处理对Dyract复合体修复楔状体缺损的临床效果的影响。方法：酸蚀处理后用Dyract修复楔状缺损牙160颗,不酸蚀处理直接用Dyract修复142颗,用改良的USPHS系统对2年后的临床疗效进行评估。结果：实验组的成功率为92．5％,对照组的成功率为80．98％。两组成功率相比差异有显著性,两 组成边缘密合性和边缘着色指标上差异有显著性,实验组优于对照组。结论：在用Dyract复合体充填楔状缺损前用酸蚀处理牙釉质和牙本质可以改善修复体与牙齿的边缘密合程度。     

不同自酸蚀黏接系统对窝沟封闭剂微渗漏影响的实验研究

目的探讨不同自酸蚀黏接系统对窝沟封闭剂封闭性能和渗透性的影响。方法收集新鲜拔除的离体第三磨牙36颗,随机分成4组,每组9颗,面釉质以杯刷清洁30s;以37%正磷酸酸蚀作为对照组,以ClearFil SE Bond、XenoⅢ以及iBond分别对牙釉质进行黏接作为实验组。涂布可见光固化窝沟封闭剂3MConcise White,光照固化。每组中8颗用1%亚甲基蓝进行染色法检查微渗漏,1颗采用扫描电镜观察封闭剂渗入窝沟的深度以及窝沟封闭剂和牙体组织之间的结合界面的状况。结果Clear FilSE Bond以及XenoⅢ自酸蚀黏接时,对封闭剂微渗漏的影响与对照组相比差异无统计学意义;扫描电镜下,磷酸酸蚀、ClearFil SE Bond以及XenoⅢ组在窝沟封闭中使封闭剂与牙釉质密合性好。结论第五代自酸蚀黏接剂ClearFil SE Bond以及第六代XenoⅢ与牙釉质之间具有良好的封闭能力,可以推荐临床使用。     

低浓度钙离子对抗橙汁牙釉质酸蚀作用初探

[摘要]目的：探讨添加低浓度钙离子对橙汁酸蚀牙釉质的影响。方法：45颗离体前磨牙随机分为无添加组、钙离子加强组,空白对照组3组,每组15颗,分别浸泡于橙汁、加钙橙汁（0．4g／L乳酸钙）和去离子水中25h,每5h换液;使用电子酸度计测定每组液体pH,使用激光荧光诊断仪对釉质脱矿程度进行定量分析。结果：无添加组和钙离子加强组离体牙实验后荧光值均显著高于空白对照组（P〈0．05）,钙离子加强组离体牙实验后荧光值显著低于无添加组（P〈0．05）。结论：添加钙离子可显著对抗橙汁对牙釉质的酸蚀作用。     

酸蚀处理影响Dyract复合体修复楔状缺损的临床效果的研究

目的 :采用改良的USPHS系统评估酸蚀处理对Dyract复合体修复楔状缺损的临床效果的影响。 方法 :酸蚀处理后用Dyract修复楔状缺损牙 16 0颗 ,不酸蚀处理直接用Dyract修复 142颗 ,用改良的USPHS系统对 2年后的临床疗效进行评估。结果 :实验组的成功率为 92 .5 % ,对照组的成功率为 80 .98%。两组成功率相比差异有显著性 ,两组成边缘密合性和边缘着色指标上差异有显著性 ,实验组优于对照组。结论 :在用Dyract复合体充填楔状缺损前用酸蚀处理牙釉质和牙本质可以改善修复体与牙齿的边缘密合程度     

光固化流动复合树脂与牙釉质抗剪黏接强度和扫描电镜的实验研究

目的测试光固化流动复合树脂与牙釉质的抗剪黏接强度和观察两者所形成的黏接面。方法将39颗离体前磨牙随机均分为3组，分别应用Singlebond流动复合树脂（1组）、京津釉质黏接剂涂剂＋Singlebond流动复合树脂（2组）和京津釉质黏接剂黏接复合树脂块（3组）。从每组离体牙中随机抽取10颗试样，检测各组材料的抗剪黏接强度；扫描电镜下观察剩余9颗试样的黏接面。结果1、2两组的抗剪黏接强度小于3组（P〈0．01），Singlebond流动复合树脂在牙釉质表面形成树脂突；扫描电镜观察黏接面内存在细小裂缝及孔隙。结论Singlebond流动复合树脂与牙釉质的抗剪黏接强度能满足正畸临床要求，但它与牙釉质的黏接面内存在微小孔隙。     

4种光固化充填材料微渗漏的比较

目的比较四种光固化充填材料的充填体边缘微渗漏.方法采用染色法对充填体进行边缘微渗漏观察.结果SYENRGYR是四种材料中微渗漏最小的,Dyract AP的微渗漏较大.SYENRGYR与其他3组相比有显著性差异(P＜0.05);BEAUTIFIL和SpectrumTPH无显著性差异(P＞0.05);Dyract AP与其他3组相比有显著性差异(P＜0.05).结论SYENRGYR可能是临床修复牙体缺损的较好材料.     

人工唾液浸泡对两种自酸蚀粘接剂粘接界面的影响

目的探讨含细菌的人工唾液对两种自酸蚀粘接剂粘接界面纳米渗漏的影响。方法选用自酸蚀粘接剂Adper Prompt（AP）和Contax分别与正常牙本质粘接并制备微拉伸试件,之后将试件浸泡于含细菌的人工唾液中,分别在即刻、1周、1月、3月时取出进行硝酸银染色,用扫描电镜（SEM）观察粘接界面银沉积情况,并用NlH图像分析软件量化处理,以界面银沉积面积占断裂界面的百分比来评价界面纳米渗漏程度。结果粘接界面在即刻、1周、1月、3月时的银沉积面积百分比分别为AP：（17.00±5.40）%、（18.71±6.94）%、（22.81±5.60）%、（26.79±5.77）%;Contax：（11.90±5.17）%、（12.41±4.42）%、（14.73±3.46）%、（17.64±5.39）%。结论无论浸泡人工唾液与否,粘接试件都无法避免纳米渗漏的产生;含细菌的人工唾液浸泡会影响粘接的稳定性,其中以AP组的稳定性较差,浸泡三个月即表现出界面银渗漏程度的显著增加。     

冷热循环对牙本质黏结界面纳米渗漏的影响

目的：探讨冷热循环对牙本质黏结界面纳米渗漏的影响。方法：用透射电镜观察3种黏结系统(Adper Prompt，U-Bond，Opti Bond)有无冷热循环作用下，牙本质黏结界面银沉积情况，并用NIH图像分析软件量化处理，以银沉积面积占混合层面积的百分比来评价纳米渗漏程度。结果：各实验组和对照组银沉积面积百分比分别为AP(9．27％，8.96％)、UB(9．62％，8．75％)、OB(8．18％，9.20％)。结论：研究中所用黏结系统都不能避免纳米渗漏产生；短期冷热循环对自酸蚀黏结系统黏结界面纳米渗漏有增加的趋势。     

人工唾液浸泡对两种牙本质粘接剂粘接界面的影响

目的：探讨含细菌的人工唾液对两种牙本质粘接剂粘接界面纳米渗漏的影响。方法：选用全酸蚀粘接剂Prime Bond NT（NT）与自酸蚀粘接剂Adper Prompt（AP）分别与正常牙本质粘接并制备微拉伸试件,之后将试件浸泡于含细菌的人工唾液中,分别在即刻、1周、1月、3月时取出进行硝酸银染色,用扫描电镜（SEM）观察粘接界面银沉积情况,并用NIH图像分析软件量化处理,以界面银沉积面积占断裂界面的百分比来评价界面纳米渗漏程度。结果：粘接界面在即刻、1周、1月、3月时的银沉积面积百分比分别为NT：（10．97±5．14）％、（12．25±4．01）％、（16．49±4．43）％、（21．03±5．65）％：AP：（17．00±5．40）％、（18．71±6．94）％、（22．81±5．60）％、（26．79±5．77）％。结论：无论浸泡人工唾液与否,粘接试件都无法避免纳米渗漏的产生;含细菌的人工唾液浸泡会影响粘接的稳定性,浸泡3个月即表现出界面银渗漏程度的显著增加。     

Theory of electrochemically modulated liquid chromatography

A theoretical treatment based on models developed to describe the adsorption features of solutes at electrified interfaces is presented for the interpretation of the retention characteristics of solutes when electrochemically modulated liquid chromatography is used. The treatment is general, covering all possible compositions of the mobile phase. A number of limiting cases with practical interest is examined in detail. It is shown that the treatment can give a molecular explanation of the experimental results. According to the theoretical predictions, the dependence of the logarithm of the capacity factor, ln k′, upon the applied potential, E_appl, is affected decisively by the composition of the mobile phase. In particular, the shape of the ln k′ versus E_appl curves depends upon the presence or not of specifically adsorbed ions, the presence or not of organic modifiers and their molecular properties. The shape of these curves may be linear or quadratic over a limiting range of potentials, as found in several experimental studies, depending on the presence or not of an organic modifier in the mobile phase and the dielectric properties of the adsorbed species on the stationary phase.     

Effect of three root canal sealers on the retentive strength of endodontic posts luted with a resin cement

AIM: This investigation examined what effect three different sealers had on retention of endodontic posts (Parapost) luted with a resin cement (Panavia 21 OP). METHODOLOGY: Sixty-four single-rooted teeth were decoronated, filed, cleaned, and shaped with a size 5 Gates-Glidden drill and 0.12 taper G.T. rotary instrumentation (Dentsply/Tulsa Dental). Teeth were then divided into four groups of 16 each. Group 1 was not obturated, and served as a control. The other three groups were obturated with gutta-percha using a different sealer for each group. Group 2 used a eugenol containing sealer (Kerr Pulp Canal Sealer), group 3 a resin sealer (AH-26), and group 4 a calcium hydroxide sealer (Sealapex). After 1 week's storage at 100% humidity, 10-mm deep post spaces were prepared with a size 6 Gates-Glidden drill, and size 5 Paraposts were cemented. Following 48 h of storage, samples were mounted in a PVC pipe with acrylic, and the posts were removed vertically using a universal testing machine at 1 mm min-, with data recorded in kilograms. RESULTS: The mean values of force required to remove the posts were: group 1 = 61.80, SD = 16.21; group 2 = 43.14, SD = 14.66; group 3 = 48.54, SD = 17.84; group 4 = 53.52, SD = 18.77. Using anova and Bonferroni tests, group 1 demonstrated significantly greater mean retention strength values than group 2, but no other significant differences existed between groups. CONCLUSION: The chemical formulation of root canal sealers did not significantly affect the retention of endodontic posts luted with resin cement.     

循环加载对牙本质黏结界面纳米渗漏的影响

目的:探讨循环加载对牙本质黏结界面纳米渗漏的影响。方法:选用3种黏结系统:Prime & BondNT(NT),Adper Prompt(AP)和Contax。用扫描电镜(SEM)观察这3种黏结系统在有无循环加载的作用下,牙本质黏结断面银渗漏情况,并用NHl图像分析软件量化处理,以界面银沉积面积占断裂界面的百分比来评价纳米渗漏程度。结果:各对照组银沉积面积的百分比分别为NT(11.48%±2.84%)、AP(21.18%±3.66%)、Contax(14.30%±2.52%),实验组分别为NT(25.20%±4.69%)、AP(38.96%±8.78%)、Contax(29.94%±4.51%)。结论:无论加载与否,所用3种黏结系统都不能避免纳米渗漏的产生;循环加载使黏结系统黏结界面纳米渗漏增加,尤其以AP最为显著。     

Nanomechanical properties of biochemically modified dentin bonded interfaces

The effect of biomodification of dentin matrices using collagen cross-linkers, glutaraldehyde (GD) and grape seed extract (GSE), on the reduced modulus of elasticity (Er) and nanohardness (H) of the hybrid layer and underlying dentin was investigated at the dentin-resin bonded interface. The coronal dentin of nine molars were exposed and divided into groups: 5% GD, 6·5% GSE and control. Control samples were etched, bonded with Adper Single Bond Plus and Premise composite. GD and GSE were applied for 1 h prior to bonding procedures. After 24 h, samples were sectioned, and resin-dentin beams were either kept in distilled water or exposed to collagenase treatment for 24 h. Nano-indentations were performed at the hybrid layer and underlying dentin. GD and GSE treatment increased the Er and H of resin-dentin interface structures when compared to the control group (P<0·05), particularly the hybrid layer, and may be a promising novel approach to strengthen the dentin-resin bonded interface structures when using these adhesive system and resin-based composite.     

Compact poly-pyrrole layers formed at a liquid|liquid interface

Polymerization of surface active derivatives of pyrrole at the water|1,2-dichloroethane interface leads to the formation of a compact layer. New monomers have been synthesized with two pyrrole units in the molecule. Polymerization of these monomers proceeds at a lower potential and the density of the polymer layer is higher compared with monomers with one pyrrole unit in the molecule. Formation of the polymer layer has been monitored by cyclic voltammetry in the presence of transferable ions of different size and charge. Permeability of the polymer layer can be affected by the presence of a surface active derivative of cyclodextrin in the polymerization process.     

Electron transfer across the single micro-water-droplet|oil interface using microcapillary injection and microelectrode methods

Electron transfer (ET) between a hexacyanoferrate(III) ion in a single micro-water-droplet and a ferrocene derivative (Fc), such as decamethylferrocene, in 2-nitrophenyl octyl ether was studied using microcapillary injection and microelectrochemical techniques. The overall ET rate constant increased with the decreasing Gibbs energy (ΔG), consisting of the Galvani potential between the water and oil phases and the redox potential difference of the solutes, and was saturated at a ΔG value less than ?15 kJ mol^?1. The ΔG dependence of the overall ET rate was discussed in terms of the interfacial ET coupled with the microscopic diffusion of Fc in the vicinity of the water|oil interface.     

Double layer capacitance and a microscopic structure of electrified liquid–liquid interfaces

We develop a theory of the double layer at electrolyte–electrolyte interfaces taking in to account the microscopic structure of the interfacial region. This includes a “mixed boundary layer” where the overlapping of two space-charge regions occurs, and the effects of ion association and adsorption at the interface. Theoretical results are in good agreement with experimental data obtained for various organic solvents and electrolytes. The theory suggests a framework for the treatment of the capacitance data and establishes a relationship between experimental results and the microscopic structure of interfaces between two immiscible electrolyte solutions (ITIES).