无水硫酸钙晶须对义齿软衬材料机械性能的影响

背景：由于义齿软衬材料自身理化性能的限制,近些年有人将晶须材料添加到软衬材料中,以增强其机械性能。 目的：观察不同无水硫酸钙晶须添加量对自凝软衬垫机械性能的影响。 方法：实验分6组,在自凝软衬材料中分别添加含量为0(对照)、1%、2%、3%、4%、5%的无水硫酸钙晶须,每组10枚试件,共60枚试件,检测其剪切黏结强度、邵氏硬度及拉伸强度。 结果与结论：随着无水硫酸钙晶须添加量的不断增加,软衬材料的邵氏硬度不断升高,拉伸强度先升高后降低;当无水硫酸钙晶须添加量为3%时,软衬材料的黏结强度与拉伸强度最高。综合3项指标来看,当无水硫酸钙晶须添加量为3%时,软衬材料的机械性能最佳。表明无水硫酸钙晶须可影响自凝软衬垫的机械性能。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

新型硅橡胶人工晶状体兔眼植入的生物相容性评价**

背景：软性人工晶状体的材料主要有硅凝胶、疏水性丙烯酸酯、亲水性丙烯酸酯和水凝胶等,但各材料优缺点不同,其长期生物学特性仍待临床检验。为改善白内障术后的视觉质量,提高人工晶状体的生物相容性及光学性能,进行新材料的开发是目前研究的热点。 目的：评价自主研制的新型硅橡胶后房型人工晶状体兔眼植入半年的生物相容性。 方法：选取20只新西兰白兔,均单眼行透明晶状体超声乳化吸除术联合人工晶状体植入,实验组(10眼)植入自主研制的硅橡胶(T-10)后房型人工晶状体,对照组(10眼)植入现已上市的硅凝胶后房型人工晶状体(EFC550)。 结果与结论：植入后早期,两组兔眼均有较重的前房渗出,差异无显著性意义。两组兔眼后囊膜混浊程度差异无显著性意义。植入后90 d及180 d,实验组虹膜后粘连情况轻于对照组。可见新型硅橡胶人工晶状体色素层生物相容性优于硅凝胶人工晶状体,具有临床可应用性。     

人发角蛋白凝胶对L-929细胞的增殖作用研究

利用人发角蛋白良好的可降解吸收和生物相容性,研究其作为软组织填充材料的可行性。实验以人发为原料,通过提取、纯化等方法获得角蛋白的水溶液,并制备成可注射的凝胶,研究采用SDS-PAGE对角蛋白的组成进行表征,通过对膜的吸水性实验表征凝胶的水合性能,并使用MTT法对凝胶材料的细胞增殖作用进行评价。SDS-PAGE结果显示提取的角蛋白分子量集中在30、50和65KD左右,角蛋白具有快速吸水性能且吸水率可高达850%,人发角蛋白对L-929小鼠成纤维细胞表现出明显的增殖作用,在24、48、72 h的平均增殖率分别达到119%、122%和123%。实验制备的人发角蛋白凝胶对L-929细胞具有明显的增殖作用,具有作为软组织填充材料的应用前景。     

胎儿血管铸型填充材料的应用研究

目的 探索20%的过氯乙烯和自凝牙托材料进行不同比例配置形成混合填充剂用于胎儿血管铸型材料.方法 按不同比例配置20%的过氯乙烯和自凝牙托材料,观察混合物在胎儿血管标本中流动性、凝固后材料的硬度和柔韧度,得出最佳的配制比例.结果 以自凝牙托水100 mL,邻苯二甲酸二丁酯20 mL,自凝牙托粉70 g为配方基础的自凝牙...     

掺锶复合PVA/生物活性玻璃水凝胶的制备及其体外软骨修复性能研究

目的研究以聚乙烯醇(PVA)、生物活性玻璃(BG)及氯化锶为主要原料,制备的PVA水凝胶、PVA/生物活性玻璃水凝胶、掺锶复合PVA/生物活性玻璃水凝胶的可降解性能、离子释放性能和促软骨修复性能。方法PVA溶液与BG溶胶凝胶溶液在加热搅拌下生成PB水凝胶,PVA溶液与Sr-BG溶胶凝胶溶液加热搅拌生成PBSr水凝胶,将PB和PB-Sr水凝胶浸泡于磷酸盐缓冲液(PBS)中,研究其体外降解性能、离子释放性能和结构变化。在水凝胶上培养软骨细胞,经细胞增殖能力实验和细胞荧光染色观察细胞增殖情况。结果 PB和PB-Sr水凝胶在PBS溶液中逐渐降解,28 d后PB水凝胶降解率为25%,PB-Sr水凝胶降解率为16%,水凝胶表面均有羟基磷灰石形成。细胞实验结果显示培养7 d后PB-Sr水凝胶的OD值为0.76±0.04,PB水凝胶的OD值为0.52±0.02,均显著高于对照组,PVA水凝胶的OD值0.45±0.04,差异具有统计学意义(0.05)。结论该掺锶复合PVA/生物活性玻璃水凝胶具有良好的降解性能和离子释放性能,能有效促进软骨细胞增殖。     

力学性能可控的甲基丙烯酸化明胶（GelMA）人工软骨性能及软骨/骨表界面结合研究

目的 探寻优化骨表面力学匹配的软骨修复材料,并探讨软骨修复材料与骨结合的表界面性能,为软骨修复材料的设计及制备提供依据。方法 以明胶和甲基丙烯酸酐为原料,在明胶分子中引入双键结构,使用紫外光交联的方式制备甲基丙烯酸化明胶（GelMA）水凝胶。运用扫描电子显微镜、万能力学试验机分析水凝胶的形貌、孔径大小和力学性能;体外降解实验、体外拉伸实验评估水凝胶的降解和拉伸特性;黏附能力定性实验、三维立体光学显微镜和扫描电子显微镜评估水凝胶的黏附能力;细胞增殖测试和Live/Dead染色测定细胞活性和毒性。探讨了不同紫外光照时间下GelMA水凝胶的理化性能及软骨/骨材料结合的表界面结合性能,对性能适宜的修复材料进行了配比、力学优化。结果 紫外光照（UV）交联时间为1 min时水凝胶孔隙最大（110.25±6.51）μm,孔隙率高达（45.24±2.78）%;12 h时水凝胶的平衡溶胀比达（148.43±3.84）%;28 d失重率为（17.40±2.38）wt%;水凝胶的拉伸性能随紫外光照时间延长而逐渐增加;GelMA水凝胶对骨髓间充质干细胞增殖无明显抑制作用;水凝胶软骨修复材料与骨的结合良好,可黏附于仿生骨材料表面。结论 紫外光照交联时间1 min时GelMA水凝胶的吸水速率和平衡溶胀比最佳,降解速快,拉伸性能与天然软骨结构类似,具有良好的生物相容性,与骨修复材料力学匹配,该力学性能可控的GelMA水凝胶软骨修复材料为软骨/骨的连接及性能匹配提供了依据。     

新型自组装水凝胶NBD/RADA16可促进前成骨细胞的分化

背景：RADA16是较成熟的自组装纳米短肽材料,在亲水面往复形成互补离子键,可组装为纳米纤维,并且能够促MC3T3 E1细胞的黏附、伸展和增殖。 目的：观察新型自组装多肽水凝胶NBD/RADA16对小鼠前成骨细胞MC3T3 E1成骨分化能力的影响。 方法：将MC3T3 E1细胞分别接种于自组装多肽水凝胶NBD/RADA16与RADA16水凝胶中,进行成骨诱导培养,以单纯成骨诱导培养的细胞为对照。诱导培养1,3,6 d检测细胞碱性磷酸酶活性;诱导培养7 d后,Western Blot检测细胞骨形态发生蛋白2的表达;诱导培养21 d后,茜素红染色观察细胞钙化结节。 结果与结论：MC3T3 E1细胞在NBD/RADA16多肽水凝胶上生长状态良好,优于在RADA16上生长的细胞。自组装多肽水凝胶NBD/RADA16上MC3T3 E1细胞的碱性磷酸酶活性高于RADA16水凝胶上及单纯成骨诱导培养的细胞(P < 0.01)。自组装多肽水凝胶NBD/RADA16上MC3T3 E1细胞的矿化基质沉积、骨形态发生蛋白2表达高于RADA16水凝胶上的细胞(P < 0.01)。结果提示NBD/RADA16自组装多肽水凝胶较RADA16水凝胶更能促进MC3T3 E1细胞的成骨分化。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

牙托粉串骨架新法

我们采用网拍弦和牙托粉、自凝牙托水、邻苯二甲酸二丁酯等材料作连接物,经过多年的实践,摸索出了一种简单快捷,关节及整体形状较好的全身骨架串制方法。用此方法制作的骨架,不论是用于教学还是陈列,均具有牢固、自然美观等优点。１材料（１）网拍弦、铜丝、自换牙托粉、自凝牙托水、邻苯二甲酸二丁酯等。自凝牙托粉与自凝牙托水按１：１的比例制成填充剂,再根据骨架的颜色加入油画颜料,为延长凝固时间,加入适量邻苯二甲酸二丁酯（但浓度不宜超过２０％）或甲基丙烯酸丁酯。（２）取年龄在３０岁左右,骨质坚硬的新鲜标本经煮沸、脱…     

超亲水性医用导管的制备及其动物体内组织相容性研究

利用天然高分子葡聚糖(Dextran)和烯丙基异氰酸酯(AI)反应,首先合成了预聚物Dex-AI,然后预聚物Dex-AI再与聚乙二醇二丙烯酸酯(PEGDA)反应,制备了具有良好亲水性和生物相容性的水凝胶(DP)。同时探索了反应物比例对最终产物的影响,结果是在Dex-AI∶PEGDA为4∶6(质量比)时,所制得的水凝胶DP的吸水率最大,可达810%。将此水凝胶接枝于经二苯甲酮在紫外光下处理的临床用导管表面,经静态和动态表面接触角测试,接枝有水凝胶的导管其表面亲水性显著提高,如静态表面接触角由水凝胶接枝前的(97±6.1)°下降到了接枝后的(25±4.2)°。另一方面,以小鼠(ICR,30只)为实验动物,将接枝前后的导管植入小鼠背部皮下,观察时间为30 d。发现导管经DP接枝后,反映急性炎症情况的白细胞水平始终低于未接枝的样本;大体观察和组织学检测也发现,与未接枝的导管相比,在相同的时间点接枝DP的导管其炎性程度明显下降,导管与周边组织相容性提高。本研究证实了接枝水凝胶的技术可以提高目前临床用的PE导管的组织相容性,这对改善因治疗需要导管较长时间置留于体内而对患者带来的不良影响是非常有利的。     

002 以填充胶原、白蛋白和丝蛋白的硅橡胶管引导周围神经组织再生[英]

'Chen Yueh-Sheng…//Biomaterials.-2000,21 (15).-1541～1547 对于较小的神经缺损可以采用直接缝合的方法进行修复,但较大的缺损就需进行神经移植或使用导管连接神经断端.由于神经移植存在供体不足的问题,使用导管连接神经断端受到较多重视.已有许多种材料被研究用于制备导管,硅橡胶是研究较多的材料.为了能修复更大的神经缺损,多种神经营养因子和促进神经再生的因子被使用,如何使这些因子能较长时间发挥作用是很重要的研究课题.本工作在鼠坐骨神经上形成1cm的缺损,用硅橡胶导管连接神经断端,并注入含有胶原、白蛋白和丝蛋白的凝胶.凝胶是由胶原溶液、白蛋白溶液和丝蛋白溶液按一定比例混合后在低温下形成的.以未填充凝胶的硅橡胶导管连接作为对照.在手术6周后,所用填充的凝胶均全部分解吸收,导管无明显的膨胀.实验组中90%的动物显示了穿越缺损的神经再生,而对照组只有60%.定性和定量组织学分析显示实验组再生神经截面较对照组大28%,神经元数量也大.结合其他研究者实验结果表明使用此类凝胶可以促进周围神经缺损再生.(陈晓东摘朴东旭校)     

Study on Mechanical and Biological Properties of Autopolymerizing Hydrogel for Denture Soft Lining Material

Denture soft lining materials have been recongnized in prosthodontic clinicalpractice for many years.They act as enabling uniform distribution of pressure ondenture- bearing tissues and reducing discomfort for patients with sharp or severelyreabsorbed alveolar ridges and sensitive mucosa〔1〕.However,the present two mainkinds of soft liners still existsome shortcomings respectively,i.e.the plasticizeacrylics may become harder and harder as the using time passed;the silicone elas-tomers may pre…     

Sorption and solubility testing of orthodontic bonding cements in different solutions

To evaluate and compare the solubility and sorption of orthodontic bonding cements after immersion in different solutions, five different cements were used: a fluoride-containing resin composite, a light-cured glass ionomer cement, a light-cured resin composite, a paste-paste chemically cured resin composite, and a liquid-paste chemically cured resin composite. Five different solutions were employed: distilled water, artificial saliva, an alcohol-free mouthrinse solution (Orthokin), a 5% alcohol mouthrinse solution (Perioaid), and a 75% ethanol/water solution. Five disc specimens (15 mm x 0.85 mm) were used for each experimental condition. Materials were handled following manufacturers' instructions and were ground wet with silicon carbide paper. Solubility and sorption of the materials were calculated by means of weighing the samples before and after immersion and desiccation. Data were analyzed by two-way ANOVA and Student-Newman-Keuls test (p < 0.05). The light-cured glass ionomer cement showed the lowest solubility and the highest sorption values. When using alcohol-containing solutions as storage media, solubility of the paste-paste chemically cured resin composite increased, and sorption values for the tested chemically cured resin composites were also increased. The use of alcohol-free mouthrinses does not affect sorption and solubility of orthodontic cements. The chemically cured (paste-paste) composite resin cement, requiring a mixing procedure, was the most affected by immersion in alcohol-containing solutions.     

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.     

Water sorption,solubility and dimensional changes of denture base polymers reinforced with short glass fibers

The aim of this study was to determine water sorption, solubility and dimensional stability of injection and compression-molded polymethyl methacrylate based denture base polymer that was reinforced with various concentrations and lengths of E-glass fibers. For water sorption and solubility, 20 test groups with different fiber contents and lengths of fibers were prepared. Test specimens without fibers were used as a control. The water sorption and solubility was measured after 90 days water storage. For dimensional stability, rhombic test specimens were prepared and the dimensional changes were measured after processing, drying and storing in water for 4 days and 30 days and were compared with those on the brass model. The water sorption and solubility of injection-molded denture base polymer was lower compared to compression-molded specimens (p < 0.05). The dimensional accuracy of denture base polymer was not affected with fiber reinforcement (p > 0.05).     

Viscoelastic properties of some soft lining materials. II--Ageing characteristics.

A non-resonant forced vibration, dynamic mechanical analyser was employed to measure the viscoelastic characteristics of soft lining materials at 1 Hz, after storage in distilled water at mouth temperature for periods up to and including one year. The six commercial products included methacrylate, silicone, and phosphazine based polymers and the one experimental material was a methacrylate. Water sorption of the soft liners, recorded by change in sample mass, ranged from -4.39 to +48.57% and their solubilities from 0.13 to 13.58%, after one year. The heat-cured silicone was the most stable polymer in water in contrast to its autopolymerised counterpart. The excessive water uptake of this latter material resulted in a massive reduction in modulus. At the other extreme one methacrylate with a high plasticiser content hardened substantially after ageing (modulus changed from 5.87 to 72.3 MPa). Changes in loss tangent data were relatively small for all the polymers tested, even for materials with high water uptake. Reduced leaching and/or plasticiser content have led to a more stable generation of soft lining materials.     

三种全口义齿重衬材料临床应用的比较

背景：对于无牙颌患者而言,由于牙槽嵴的吸收,全口义齿戴用一段时间后,口腔黏膜与基托不密合,出现义齿固位不良,临床上常采取基托重衬解决义齿固位问题。 目的：观察Sofreliner MS软衬材料、自凝树脂和热凝树脂3种材料在不同牙槽嵴和黏膜条件患者中全口义齿重衬后的临床效果。 方法：选择2009-09/2011-09期间就诊于内蒙古医学院附属医院口腔修复科中为牙槽嵴、牙龈条件优和劣组患者各30例,将牙槽嵴、牙龈条件优和劣组各随机等分为3个亚组分别采用Sofreliner MS软衬材料、自凝树脂、热凝树脂进行全口义齿重衬,衬垫1年后复查,比较3种材料重衬后的义齿固位、舒适度、咀嚼功能恢复的满意度及清洁情况。 结果与结论：牙槽嵴、牙龈条件劣组患者中采用Sofreliner MS软衬材料重衬义齿的修复效果明显优于自凝树脂、热凝树脂(P < 0.05);而牙槽嵴、牙龈条件优组中3种材料的修复效果差异无显著性意义(P > 0.05)。提示对于牙槽嵴、牙龈条件差的患者,应用Sofreliner MS软衬材料重衬义齿可使义齿稳固、舒适、并有效提高咀嚼功能。 关键词：软衬材料;全口义齿;义齿重衬;牙槽嵴;固位 doi:10.3969/j.issn.1673-8225.2012.12.042     

Improved wettability of an experimental silicone rubber denture soft lining material

The purpose of this study was to improve the wettability of an experimental silicone rubber soft lining material (Sildent) to increase patient comfort. Sildent was modified by the addition of polyalkylene oxide poly(dimethylsiloxane) surfactants. The various surfactants were added directly to the polymeric matrix in the quantities 5, 10, 20% w/w. The surfactants were also added to a one part silicone sealant, which was then painted onto the surface of already cured Sildent. Contact angle measurements were made on samples using a dynamic contact angle analyzer. Results showed that incorporation of surfactants A (Silwet L7600) and B (Silwet L7607) effectively improved the wettability of Sildent. This improvement was still evident after 6 months storage in distilled water at 37 degrees C suggesting retention of the surfactants matrix via physio-chemical bonding. Formulations with surfactants added directly to the matrix showed unacceptable water absorption after 2 months in distilled water. Samples with surfactant charged sealant painted on the surface showed a lower water absorption. In conclusion, Sildent formulations modified with polyalkylene silicone surfactants showed improved wettability compared to unmodified Sildent. Further work is needed to reduce water uptake and determine the effect on key mechanical properties.     

Adhesive bonding of denture base resins to plastic denture teeth

The adhesive bonding of denture teeth to denture base resins in dentures with conventional acrylic teeth and crosslinked plastic teeth was investigated. The dentures with highly crosslinked plastic teeth such as SR-Orthosit, Crystal ND, and Mitel-OM showed poor bonding at the tooth/base resin interface using the conventional bonding method. Elimination of the alginate mold lining material in the conventional bonding method effectively improved bonding at the tooth/base resin interface. The application of 4-META adhesive bonding agents to the denture teeth improved the interface bonding of highly crosslinked plastic teeth and the denture base. Dentures with Orthosit and Mitel showed differences in bonding ability when two different adhesives were used.     

Water-sorption kinetics of dental polymeric resin under tensile stressing conditions.

Water sorption tests were conducted on unfilled poly(methyl methacrylate) samples in distilled water at 5, 37, and 60 degrees C under three different tensile stress ratios (sigma appl/sigma ys = 0%, 5%, and 10%). Each sample was placed in a modified Hoffman open-side tubing clamp and subjected to four-point bending at pre-determined stress level for 1 day, 3 days, 1 week, 2 weeks, and 4 weeks. Water sorption was measured by weight change calculations, without accounting for any weight loss due to solubility of uncured monomer. A generalized diffusion equation can be used to express both stress-free and stress conditions; D = D0exp[-E (sigma)/kT]. It was found that the activation energy for water sorption diffusion was linearly related to applied stress ratios; i.e., E = 1.15 sigma appl/sigma ys + 10.76 (kJ/mol), with the correlation coefficient r = 0.97. Since the proportional pre-exponential constant, D0, is independent of temperature, it is speculated that the loading percentage of reinforcing filler elements in composite resin materials can be related to this constant.     

Effect of resin hydrophilicity and temperature on water sorption of dental adhesive resins

This study examined the effects of copolymer hydrophilicity and temperature on water sorption and solubility characteristics of five copolymer blends of increasing degree of hydrophilicity using gravimetric measurements. Six resin disks (15 mm in diameter x 1 mm in thickness) were prepared from each copolymer blend and were stored in deionised water at 23, 37 and 55 degrees C. Water sorption and solubility of the resin disks were measured before and after water immersion and desiccation. Multiple regression analysis of water sorption was performed on two independent variables, copolymer hydrophilicity and temperature. Maximum water sorption increased significantly with Hoy's total cohesive energy density (delta(t)), Hoy's solubility parameter for polar forces (delta(p)) and hydrogen bonding (delta(h)), but was not influenced by temperature. However, a significant positive relationship was observed between diffusion coefficients (obtained using Fick's law of diffusion) and temperature. The water absorption activation energy was 10 kJ/mol for the most hydrophilic copolymer blend R5 and 35-51 kJ/mol for copolymer blends R1-R4. The positive relationship between maximum water uptake and copolymer hydrophilicity suggests that water molecules diffuse through the polymer matrices by binding successively to the polar sites via hydrogen bonding. Such water sorption may determine the durability of resin-dentine bonds.