改良自凝牙托材料在脏器铸型标本中的应用

用自凝牙托材料制作的铸型标本难以达到细小分支 ,韧性差 ,铸型较脆弱 ,细小枝容易断裂 ,所以影响其在多管道铸型和细小管道中的应用。我们改进了配制方法 ,增加自凝牙托水和增塑剂的用量 ,将其用于脏器管道铸型 ,在灌注粗大管道和细小管道 ,铸型效果都较理想。1　标本制作法取     

用AB胶与过氯乙烯混合填充剂制作铸型标本

正填充剂对于铸型标本的成败起着关键性的作用,通常采用自凝牙托材料、塑料ABS、过氯乙烯等塑料材料。由于这些填充剂的成型灌注原理不同,铸型效果各有优缺点,前者属化学反应成型,铸型标本分枝饱满且一次成型,但柔韧性差;后两者属溶剂挥发后凝固成型,具有较好柔韧性,但需多次补充灌注铸型才饱满,有作者将自凝牙托材料和过氯乙烯混合使用作为填充剂获得成功~([1-3])。通过多年的实践,笔者采用AB胶与过氯乙烯混合材料灌注铸型标本,也可以综合两类成型法之优点,取长避     

胰腺血管铸型的设计与制作

目的 应用管道铸型的方法直观显示胰腺的血管来源、走向、分支以及与相邻脏器的相互联系.方法 采用过氯乙烯和自凝牙托两种材料,对新鲜成人尸体2具,经胸主动脉及肠系膜上下静脉行多器官联合血管灌注;经胰管、腹主动脉、肠系膜上动脉行胰腺动脉及胰管联合铸型.结果,通过本方法制作出腹部多脏器联合铸型标本及胰腺动脉及胰管联合铸型标本....     

用自凝牙托材料制作软体解剖标本

在血管灌注技术资料中,自凝牙托材料多用于制作铸型标本,若制作解剖剥制的软体血管标本,多采用灌注乳胶、明胶、墨汁等方法[1~3]。有些地区采购乳胶材料困难,而牙托材料在一般医药商店可随时购买。我们通过实验研究,用自凝牙托材料,在铸型     

配色硅玻璃胶在心肺肝等多管道铸型标本中的应用

作为建筑和装饰材料用的硅玻璃胶 ,已有作者将其应用于支气管树、内耳以及心肺等单一管道铸型 ,具有成型快、铸型饱满、收缩率低 (0 .5 % )、韧性好等特点[1 5] 。但硅玻璃胶铸型标本的支撑力较差 ,往往不能维持标本的自然形态 ,又因采用原色灌注或铸型后上色 ,而大大地影响了其在某些铸型标本尤其是在多管道铸型中的应用 ,为此 ,我们改进了操作方法 ,将硅玻璃胶配成各种颜色 ,结合过氯乙烯、自凝牙托材料等填充剂的性能特点 ,多种填充剂配合使用 ,收到了很好的效果 ,铸型标本既有弹性和韧性 ,也有刚性。1　材料的准备　 (1 )填充剂材料 :①…     

应用硅氧烷—水晶胶制作铸型标本

铸型标本的填充剂目前国内应用挥发成型、化学成型两种。挥发成型以塑料类为代表。化学成型以牙托材料为代表。挥发成型的填充收缩大，需多次补注，铸型易塌陷。牙托材料填充剂凝固时间短，一次成型不须补注，铸型饱满，但脆性大，只适合内脏器官灌注铸型。     

保留骨骼的胎儿全身及胎盘血管联合铸型标本的制作

由于胎儿骨骼的组成成分上,有机质大大超过无机质,胎儿保留骨骼的血管铸型标本制作,比常规的保留骨骼铸型标本难度大。为了清楚地显示胎儿、胎盘脉管系的立体构造和整体性,以及胎儿血管与骨骼的毗邻关系,我们在前期成功制作胎儿全身血管铸型标本的基础上,选择妊娠晚期的胎儿标本,用改良自凝牙托材料为填充剂,饱和Ca（OH）2的乙醇碱液腐蚀,制作了保留骨骼的胎儿全身血管及胎盘血管联合铸型标本,效果良好,现报告如下。1材料与方法     

支气管肺段的分色铸型法

支气管肺段铸型标本的分色显示多采用按段喷染法制作 (李忠华 ,人体铸型标本的设计和制作 ,华南理工大学出版社 ,1 992 .64～ 65 )。我们在对支气管肺段铸型标本的研制中 ,采用了按段分色灌注铸型法。1　制作器械和材料　输液管、塑料注射器、手术用小圆针和 1号细丝线、血管钳等器械 ;自凝牙托粉、自凝牙托水、邻苯二甲酸二丁 (辛 )酯、5～ 1 0种色的油画颜料及 5 0 2胶等材料。 2　制作步骤　 (1 )自气管胸段以下完整地取出气管至肺 ;(2 )沿各叶支气管前壁纵行剪开各叶支气管 ,直至找到各段支气管开口 ,于该口处插入一段输液管 (皮条一端…     

多点插管法制作上肢离体铸型标本

目的研究显示上肢动脉铸型标本方法,为临床应用及教科研提供直观细致的局部循环标本。方法截取新鲜成人尸上肢6例,从腋动脉、尺动脉及桡动脉分别向肢体两端进行多点灌注牙托、过氯乙烯等填充剂,然后进行腐蚀冲洗处理。结果上肢动脉铸型标本外形美观,具有结构完整性和连续性,血管分支毗邻关系明确,疏密有度。结论采用沿动脉管道多点插管灌注法是制作上肢动脉铸型标本较为有效的方法。     

铸型标本设计的体会

<正> 在常用的铸型填充剂中,过氯乙烯和ABS塑料是属于溶剂挥发后凝固成型法的填充剂,其特点是流动性好,硬固慢.铸型韧性优良,分枝细密,适用于灌注口径小流程长的管道,例如四肢和头颈部的铸型标本,自凝牙托材料和环氧树脂是属于聚合反应成形填充剂,其特点是硬固快,刚性强,铸型饱满坚实,分粗疏,适用于灌注管径     

应用聚甲基丙烯酸甲酯制作兔肾小球铸型

目的:探索采用聚甲基丙烯酸甲酯填充剂进行兔肾小球铸型的效果。方法:胸主动脉插管,应用聚甲基丙烯酸甲酯填充剂灌注肾动脉。结果:肾动脉及其大分支血管饱满,连续性好,肾小球肉眼可见,光镜下呈黑色球状,可见肾入球及出球小动脉,扫描电镜示肾小球内部毛细血管网及其次级分支,血管线形流畅,表面光滑。结论:采用聚甲基丙烯酸甲酯作为肾小球铸型填充剂,肾小球显示清晰、完整,能达到预期效果。     

Measurement of strain rate behaviour in complete mandibular dentures

A major cause of fracture in complete lower dentures is due to the denture falling onto a hard floor. Impact failure has never been investigated in complete dentures and in a material which is strain rate dependent, a knowledge of the maximum strain and strain rate at failure is essential if laboratory tests are to evaluate materials in a realistic manner.The work described includes brittle lacquer studies to establish the strain pattern which occurs when a denture is dropped fm a height of 1 metre. This was used to orientate strain gauges and experimental dentures were then hit by a specially constructed ram driven at known velocities by a spring, whilst the strain was recorded on a storage oscilloscope. Photographs of the stored wave form were then used to establish the results at ram velocies equal to that of a denture falling 1 metre. Maximum strains were achieved of 11 × 10³ microstrain and strain rates of 1.04 × 10³ microstrain/ms. Laboratory impact machines for testing denture base materials should therefore be designed to achieve these figures.     

管道铸型技术与血管造影3D可视化相结合

目的:以肝为例,探索将管道铸型与血管造影及3D可视化技术进行整合,充分揭示同一器官内部各管道系统之间的相互关系。方法:分别从肝静脉灌注自凝牙托灌注填充剂,从肝门静脉灌注乳胶、羧甲基纤维素-氧化铅填充剂。运用多层螺旋CT进行层距0.5mm薄层扫描,获取二维数据,应用Mimics软件对肝内的管道系统进行3D可视化。结果:重建后的肝门静脉充盈饱满,层次清晰,边缘光滑,层次分明。排除干扰后,自凝牙托材料灌注的肝静脉同样可以在运用CT扫描后,获取理想的管道三维重建模型。图像融合后能清晰显示肝门静脉和肝静脉在肝内的相互位置关系。结论:采用管道铸型技术与血管造影3D可视化相结合技术,不仅能在同一器官同时显示各管道系统的相互关系,更能在同一器官分别显示各管道系统。     

Comparison of effects of bleach and cleansing tablet on reflectance and surface changes of a dental alloy used for removable partial dentures

Proper hygienic care of removable partial dentures is important for maintaining a healthy oral mucosa. A daily home care routine is the responsibility of the patient to maintain oral hygiene. A dentist must inform the patient about denture cleansers used for plaque control. Common denture cleansers may negatively affect the surface of alloys used to make partial dentures. The purpose of this study was to evaluate whether bleach and cleansing tablet have deleterious effects on the surface of a dental alloy used to fabricate removable partial dentures. Nineteen test specimens were prepared from CoCr dental alloy. The specimens were cast into 10 mm long x 10 mm wide x 1 mm thick. Fresh solutions made from a commercial bleach and a commercial cleansing tablet were used for each treating. Three groups (commercial denture cleansing tablet, bleach and tap water) were tested. Six specimens were immersed in 200 mL of tap water containing a single denture cleansing tablet. Two spoons of the commercial bleach was added to 200 mL of tap water. Seven specimens were treated. The control specimens were immersed in 200 mL of tap water. Six specimens were the control group. Each specimen was immersed for 30 min per day in the solution for a period of 30 days. The specimens were analyzed for reflectance with a spectrophotometer, for surface changes with a light microscope and weight which was measured with sensitive balance before and after treatment. The SPSS program was used for the statistical analysis. The Kruskal-Wallis Test and Wilcoxon Signed Ranks Test was used. No significant changes of reflectance was shown in the Kruskal-Wallis Test (p > 0.05). The Wilcoxon Signed Ranks Test was performed for comparison into groups. The difference between before and after treatment was statistically significant for the commercial denture cleansing tablet and the commercial bleach (p = 0.028) (p < 0.05). Reflectance was decreased after treatment. Within the limitations of this study, the commercial cleaning solutions had influenced the decrease of reflectance on the surface of the dental alloy. This solutions should not be limitlessly used on dentures with metal components, because they caused clinically significant reflectance changes on the surface of the alloy after 30 days.     

四种超硬石膏模型精度及抗弯强度的比较

背景:在临床上,超硬石膏广泛应用于制作固定义齿、大支架可摘义齿等需精细复制口腔情况的工作模型,其抗弯强度足够抵抗脱模时的力量不会发生模型牙体的折断。但当印模为硬质材料如聚醚橡胶印模等,存在牙体折断现象。 目的：比较4种超硬石膏YCG,丹特纳,贺利氏,穗诚模型的尺寸精度及抗弯强度。 方法:制作三单位固定桥和长方体(50 mm× 10 mm×5 mm)的金属模具,灌注4种超硬石膏模型,分别采用万能工具显微镜和万能试验机测量其尺寸精度及抗弯强度。 结果与结论：YCG、丹特纳、贺利氏、穗诚4种超硬石膏近远中方向尺寸精度均值分别为:15.043,15.034,15.037,15.040 mm,颊舌方向为：7.020,7.015,7.019,7.019 mm,牙体长轴方向为：8.022,8.018,8.019,8.02  mm。4种超硬石膏模型抗弯强度均值分别为：15.687,13.000,22.521,18.675 MPa。4种石膏模型尺寸精度差异无显著性意义 (P > 0.05),但抗弯强度差异有高度显著性意义(P < 0.01)。贺利氏石膏抗弯强度显著高于其他3种石膏 (P < 0.01),穗诚石膏抗弯强度显著高于丹特纳(P < 0.01)。说明贺利氏石膏的抗弯强度是4种超硬石膏中最高者,穗诚的抗弯强度高于丹特纳,提示临床上应根据实际情况尽量选择抗弯强度大的石膏材料。     

注塑微波法制作树脂基托对义齿精度的影响

背景：近年来,注塑微波聚合技术在临床应用越来越多,其制作义齿精度方面的研究在国内鲜见报道。 目的：观察注塑微波方法对树脂基托义齿精度的影响。 方法：用注塑微波法和水浴法分别制作上颌全口义齿各10个,然后在上颌第二磨牙远中部位切断义齿基托与标准模型,用数字显微镜测量上颌全口义齿基托组织面与标准模型之间共5个部位的间隙。 结果与结论：注塑微波法制作的义齿5个部位的精度为：(200±32),(76±13),(69±15),(81±16),(187±27) μm,水浴法制作的义齿5个部位的精度为：(243±50),(100±26),(96±30),(109±32),(213±28) μm,两种方法在相同点处差异有显著性意义(P < 0.05)。提示在精度方面,注塑微波法制作的义齿优于水浴法,并且注塑微波法聚合时间较水浴法明显缩短。     

颅脑部血管铸型标本的制作进展

目的：改良颅脑血管铸型标本的制作方法,使颅脑血管显示更加精细,以指导临床及科研。方法：使用不同配方的液体填充剂,灌注到人体器官管道内,腐蚀去除器官的其他组织,保留灌注管道内的塑料铸形,即管道铸型标本。结果：不同的填充剂、灌注方式和腐蚀方法可以达成不同的显示效果。结论：比较各种方法优缺点,得出最好显示效果的标本制作方式。     

Evaluation of adhesive properties of three resilient denture liners by the modified peel test method

The characteristics of adhesive properties between a denture base and resilient denture liner were investigated by a modified peel test with an L-shaped metal attachment. Three commercially resilient denture lining materials, namely GC Reline Soft (S), GC Reline Extra Soft (ES), and GC Reline Ultra Soft (US), were evaluated. Acrylic resin (GC Acron) was used as denture base material. Peel specimens consisting of the denture base acrylic resin and resilient denture liner were tested after storage for 1 and 30 days in distilled water at 37 degrees C. The modified peel test method gave load-displacement curves and work of adhesion (W(A)) values of the denture base material and resilient denture liner. The W(A) of specimens after 1 day of storage ranged from 1.71 to 2.55 N mm(-1) and increased in the order from US to S to ES. On the other hand, the W(A) of specimens after 30 day of storage ranged from 1.44 to 2.47 N mm(-1) and increased in the order from US to ES to S. US had significantly lower W(A) after 1 and 30 days of storage than did S and ES (P<0.05). Comparison of the W(A) between 1 and 30 days, reveals large differences for ES and US, but not for S. This could be explained by the difference in failure modes. Within the limitations of this investigation, it was concluded the modified peel test is effective for evaluating the adhesion between denture base material and a resilient denture liner.     

胎儿盲肠微血管构筑特点及其相互关系

目的为盲肠微循环提供形态学基础资料。方法通过墨汁灌注组织切片、揭层透明、微血管铸型扫描电镜等方法,观察30具胎儿尸体盲肠微血管构筑并探讨其相互关系。结果盲肠浆肌层在系膜缘侧毛细血管网眼呈与盲肠长轴平行的矩形,而靠近对系膜缘侧的毛细血管网眼多为不规则的五边形;环肌层可见环行肌束间动脉多呈"叶脉状"分为二支,分支间有横行粗短的多曲状吻合支,并由吻合支发蚓状血管;黏膜下层血管较粗网眼密度低。黏膜的毛细血管围绕结肠腺构成毛细血管丛,腺周毛细血管围成椭圆形,腺口毛细血管环均呈四边形。结论胎儿盲肠各层毛细血管网眼形状和密度均有所不同,说明盲肠血供存在部位的差异。     

A new method of producing casts for anatomical studies

The objective of the present study was to verify if polyurethane foam is a suitable material to make accurate casts of vessels and viscera, and to develop a method based on its use for anatomical studies. This new technique has been tested primarily on the lungs of different animals, but also on the renal, intestinal and equine digital vessels. It consisted of three steps: specimen preparation, injection of the foam and corrosion of the cast. All structures injected with foam were properly filled. The bronchial tree and the vessels could be observed up to their finer branches. The method is inexpensive, simple and requires no special equipment. The pre-casting procedure does not require perfusion of the specimens with formalin, or prolonged flushing with carbon dioxide gas or air for drying. The polyurethane foam does not need a catalyst. It is simply diluted with acetone, which does not cause shrinkage of the cast due to evaporation during hardening. The foam naturally expands into the cavities without high pressure of the inoculum, and hardens in just 2 or 3 h at room temperature. Only two drawbacks were observed. The first is the fact that multiple injections cannot be made in the same cavity since the foam solidifies quickly; the second is the slight brittleness of the cast, due to the low elasticity of polyurethane foam. In conclusion, polyurethane foam was a suitable material for producing accurate casts of vessels and viscera.