新型壳聚糖基温敏凝胶膜引导骨再生性能的体外实验研究

目的制备负载釉基质蛋白（enamel matrix proteins,EMPs）的壳聚糖/β甘油磷酸钠(chitosan/β-glycerophosphate salt,CS/β-GP)温敏凝胶膜,探讨其体外引导骨再生的能力。方法利用CS/β-GP体系的温敏相转变特性,制备新型生物膜并添加牛血清白蛋白（bovine serum albumin,BSA）,利用蛋白浓度测定试剂盒（加强型）检测不同时点的蛋白释放浓度,绘制蛋白缓释曲线。添加EMPs的CS/β-GP（1.0 g）复合膜作为A组; 单纯CS/β-GP（1.0 g）复合膜作为B组;同时,设空白对照组即C组,分别与ST2细胞共培养。检测膜的理化性能, MTT法检测复合膜的生物相容性, PNPP法检测碱性磷酸酶（alkaline phosphatase, ALP）的活性。采用SPSS16.0软件包对数据进行统计学分析。结果不同浓度的复合膜可缓慢释放蛋白12 d以上,并且随着β-GP浓度的升高,蛋白缓释总量增大。负载蛋白后,复合膜的理化性能均未发生显著变化（P>0.05）。MTT检测A、B、C 3组的吸光度（OD）值,组间差异具有显著性,A、B组OD值均高于C组,A组OD值高于B组（P<0.05）。A、B组ALP表达高于空白对照组（P<0.05）,A、B 2组之间ALP活性表达亦具有显著差异,A组高于B组（P<0.05）。结论负载EMPs的新型壳聚糖基温敏凝胶膜在体外实验中表现出一定的引导骨再生活性,是一种具有应用潜力的新型生物膜材料。     

壳聚糖温敏凝胶膜的制备及其生物活性初步研究

目的：制备壳聚糖/β-甘油磷酸钠（CS/β-GP）温敏凝胶新型可吸收性引导组织再生膜,通过体外细胞培养初步评价其生物相容性。方法：利用（CS/β-GP）体系的温敏相转变特性,合成温敏凝胶膜,并通过FTIR、SEM对膜的结构进行表征。MTT比色法对体外共培养的小鼠成纤维细胞（L929cell）的生长及增殖情况进行初步评价。结果：壳聚糖与β-甘油磷酸钠分子间存在静电作用和化学键结合,最终形成了新的复合生物膜,且具有多孔的表面结构和内部结构。MTT比色法显示与L929细胞体外共培养第3、4、5d,以生物膜为实验组的吸光度（A）值明显高于空白对照组,组间有统计学差异（P〈0.01）。结论：壳聚糖/β-甘油磷酸钠温敏凝胶膜具有多孔结构和良好的生物活性,能促进成纤维细胞的体外增殖,作为一种新型引导组织再膜具有良好的应用前景。     

基质细胞衍生因子-1/壳聚糖/β-甘油磷酸钠复合生物膜体外生物学特性的实验研究

目的 利用温敏凝胶制备基质细胞衍生因子-1(stromall cell derived factor-1, SDF-1)/壳聚糖(chitosan, CS)/β-甘油磷酸钠(β-sodium glycerphosphate, β-GP)复合生物膜并观察其体外生物学特性。方法 制备CS/β-GP溶液并添加SDF-1混匀,观察其37℃时凝胶时间的变化。将凝胶铺膜、干燥形成SDF-1/CS/β-GP复合生物膜,扫描电镜观察其形貌特征。将复合生物膜置于含细胞培养液的六孔板,静置6、12、24、36、48、60 h后提取上清液(n=3),测定溶液SDF-1浓度变化。将Transwell小室上室中加入骨髓间充质干细胞(BMSCs),下室置入复合生物膜,分为4组(n=3):M0组即对照组(CS/β-GP膜);M1、M2、M3组均为SDF-1/CS/β-GP膜组,分别含100、200、400 ng/mL SDF-1。分别于6、12、24 h对膜下细胞Giemsa染色观察和MTT法测定光密度(OD)值计算细胞增殖率。采用SPSS 19.0进行多因素方差分析。结果 CS/β-GP溶液加入一定量的SDF-1...     

温敏型壳聚糖/甘油磷酸钠缓释胰岛素凝胶系统的制备

目的:初步探讨制备温敏性壳聚糖/甘油磷酸钠载胰岛素凝胶系统.方法:应用壳聚糖与甘油磷酸钠制备具有温敏性的载有胰岛素的凝胶体系,从凝胶体系的pH值、粘度测定、胶凝时间研究不同配比、不同pH值对壳聚糖/甘油磷酸钠(CS/β-GP) 体系凝胶化性能的影响.结果:壳聚糖凝胶在室温(25℃)下呈液态,56% 甘油磷酸钠(β-GP)与3%壳聚糖(CS)在pH值6.8-7.2,37℃下凝胶化时间(GT) 从1h缩短到8-12min,凝胶形态良好,并且在负载胰岛素溶液后C/GP凝胶形态未受影响.结论:一定配比CS/GPS 体系在37℃具有快速凝胶化性能,在加入胰岛素后并未改变其温敏特性,为后续的温敏性壳聚糖/甘油磷酸钠载胰岛素凝胶系统的体外释药实验打下了基础.     

复合重组人骨形态发生蛋白-2缓释微球的引导组织再生膜的制备

目的设计制备包含活性生长因子的引导组织再生生物膜(以下称功能性复合膜)。方法利用天然材料右旋糖酐(dextran,dex)合成甲基丙烯酸缩水甘油酯右旋糖酐(dextran-glycidylmethacrylate,dex-GMA)作为重组人骨形态发生蛋白-2(recombinedhumanbonemorphogeneticprotein-2,rhBMP2)新型缓释载体,采用乳化交联技术制备dex-GMA凝胶微球,考察其形态、溶胀系数、载药、释药及降解性能;以壳聚糖为材料,复合载rhBMP2的dex-GMA凝胶微球制备生物膜并对其进行生物学评价。结果dex-GMA在一定条件下可以成球;该凝胶微球溶胀、载药和降解性能良好,体外释药可达20d以上,利用简单的工艺就可以制备复合rhBMP2缓释载体的功能性复合膜,其理化性能与没有复合该缓释载体的生物膜没有变化。结论利用生长因子缓释载体可以制备功能性复合膜,其生物学性能有待进一步研究。     

仿生鱼胶原复合膜引导牙周/骨组织再生的体外研究

目的 研制一种综合性能优异的仿生鱼胶原复合膜,探讨其作为引导牙周/骨组织再生（GTR/GBR）膜的生物学潜能。方法 制备一种新型仿生静电纺鱼胶原/生物玻璃/壳聚糖（Col/BG/CS）复合纳米纤维膜,分别研究复合膜的结构、性能、抗菌性及其诱导人牙周膜韧带细胞（HPDLCs）的生物学效应。结果 复合膜具有仿生结构和一定的力学强度。相比单纯的鱼胶原膜,复合膜对变形链球菌显示出一定的抑菌效果。复合膜被证明能明显促进HPDLCs的粘附、增殖成骨分化以及RUNX-2,OPN蛋白的表达。结论 本研究首次开发一种具有主动诱导牙周组织再生能力并兼有一定抗菌性的多功能仿生鱼Col/BG/CS复合纳米纤维膜,为其作为GTR/GBR膜的应用提供可能。     

木瓜蛋白酶水解β-酪蛋白膜的动力学研究

目的：采用消散因子石英晶体微天平（QCM-D）原位、实时和动态监测木瓜蛋白酶水解β-酪蛋白生物膜的动力学过程,比较不同浓度酶的水解效率。方法：用β-酪蛋白在QCM-D上建立体外蛋白膜模型,采用不同浓度的木瓜蛋白酶水解膜,观察频率和厚度的改变,运用Boltzmann方程对实验数据进行拟合,单因素方差分析和SNK-q检验比较水解参数B、Δh、V50和C。结果：随着酶浓度增大,膜的厚度Δh减薄,ΔF上升增多,水解参数B增大,C减小,V50缩短（P〈0.05）。结论：在一定浓度范围内水解蛋白生物膜时,酶的水解效率随浓度增大而提高。     

电纺羧甲基壳聚糖复合rhBMP-2生长因子纤维膜的制备

目的：利用静电纺丝技术以羧甲基壳聚糖复合生长因子（rhBMP-2）缓释微球制备牙周组织再生引导膜。方法：将载有生长因子的钙藻酸盐微球与主体羟基磷灰石（CCS/nHA）羧甲基壳聚糖混合利用静电纺丝技术制得具有＂串珠＂丝状结构的复合纤维膜,并观察微球及纤维膜的体外释药过程。结果：电纺技术制备出具有一定力学强度的缓释微球的纤维膜。体外释药在50hr时纤维膜释放速率78%,较微球的释放速率96%缓慢,之后各自接近平缓释放。结论：用静电纺丝技术平台制备缓释再生引导膜是可行的,这一技术为牙周组织再生术的完善和发展提供新的研究空间,其生物学性能尚需进一步研究。     

壳聚糖复合生物膜引导颅颌骨再生的研究

目的开发研制新型骨引导再生膜-壳聚糖复合膜用于口腔颌面外科骨缺损的修复.方法壳聚糖复合膜由可降解壳聚糖凝胶和珊瑚微晶复合而成,成膜经理化性能及生物相容性测试后植入家兔的实验性颅颌骨缺损中,设置对照组;采用不脱钙组织切片、四环素荧光示踪、放射性同位素标记、放射自显影观测以及多媒体骨组织计量学分析等手段对该膜制品促进骨创愈合的效果进行了系统的评估.结果该新型壳聚糖复合膜理化性能及生物相容性良好;体内植入与对照组相比可明显促进家兔颅颌骨创愈合(P＜0.05).结论新型壳聚糖/珊瑚微晶复合膜具备良好的引导成骨活性,可望进一步开发成一种有效的口腔颌面骨组织引导再生膜制品.     

黄芩苷和牛血清白蛋白双缓释制剂的制备及释药性能检测

目的:将黄芩苷和牛血清白蛋白(bovine serum albumin,BSA)载入壳聚糖温敏凝胶,构建双缓释体系,检测凝胶对药物的体外释放情况。方法:采用乳化缩聚法制备黄芩苷-明胶微球(gelatin microspheres,GMS);用不同配比的壳聚糖溶液和β-甘油磷酸钠(β-glycerophosphate,β-GP)溶液制备壳聚糖温敏凝胶,观察在37℃的成胶情况,选择最佳配比;在此基础上,将不同浓度的黄芩苷-GMS与BSA共混于壳聚糖凝胶溶液,测定载药后的成胶情况及黄芩苷和BSA的体外释放情况。结果:成功制备了黄芩苷-GMS,载药率5.62%,包封率72.05%;1.8%壳聚糖溶液与9%的β-GP混合10min后可获得状态良好的凝胶;加载两种药物后的凝胶溶液相转变时间未发生改变;30d时低浓度组累积释放了63.79%,两个较高浓度组分别释放了74.86%、77.63%。结论:壳聚糖温敏凝胶可以同时负载黄芩苷-GMS和BSA两种药物,在室温下呈溶液状态,37℃下经过10min可转变成半固体凝胶,在体外释药可达30d。黄芩苷和牛血清白蛋白双缓释制剂的制备和释药性能检测为牙周组织修复再生药物的研制提供了基础。     

不同剂型玻璃离子水门汀溶解性比较研究

目的:研究、比较不同剂型玻璃离子水门汀的溶解性和表面微观形态改变,为临床使用提供依据.方法:将3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)及GC玻璃离子水门汀(双糊剂型)分别在人工唾液中浸泡30 d,冷热循环15000次,烘干测重,比较前后质量变化,计算溶解率,并用扫描电镜观察表面微观改变.结果:不同剂型的玻璃离子水门汀溶解率由高到低分别为3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(双糊剂型).3种玻璃离子水门汀经浸泡溶解后,SEM扫描表面微观形态可观察到GE玻璃离子水门汀(双糊剂型)表面形态改变较少,其他2组玻璃离子水门汀表面微观改变较多.结论:双糊剂型玻璃离子水门汀理化性能及溶解率均低于传统水粉剂型,是未来临床修复治疗的的良好选择.     

Evidence of the validity of a model of determinants of quality of restorative dental care

A model describing the relationship between self-reported quality of restorative dentistry and dentist characteristics for 119 Montana general dentists is presented. The best predictors formed a significant model explaining 22% of the variance of the quality measure. Results are contrasted with a previous estimation of the model for 102 Washington general practitioners. Evidence for the external validity of the model is presented.     

Design of clinical trials of traditional therapies of periodontitis

The present paper on the design of clinical trials of periodontal therapy first addresses the issue of the etiology of periodontal disease. It is suggested that most if not all forms of destructive periodontal disease are caused by microorganisms and that there are different forms of disease with different microbial etiologies. The progressive nature of destructive periodontal disease is subsequently discussed and it is emphasized that, in a given patient, periodontal sites which show signs of inflammation and attachment loss may not over a period of several months and years show further sign of attachment loss. The present methods of assessing periodontal disease do not allow us to discriminate between potentially active and inactive sites in untreated patients. The significance and variability of indicators of periodontal disease such as bleeding on probing, probing pocket depth and probing attachment level measurements are discussed. The errors inherent in the various measurements are analyzed and suggestions are presented describing how alterations in any of the above parameters could be identified and presented in a clinical trial. Of concern for the statistical analysis of clinical data of periodontal disease is the definition of the "experimental unit". For a number of years, the "experimental unit" in periodontal trials was the patient. It is clear, however, that different sites within the same individual show different patterns of disease progression and lesion morphology and often respond differently to periodontal therapy. Statistical analyses must consequently be designed which recognize differences in site-to-site infection and lesion morphology within a common host. Until such analyses are available, the investigator should be wary of pooling data within the same individual, since such pooling may obscure meaningful alternatives which may take place in individual periodontal sites. Some goals of periodontal therapy are subsequently identified. 4 goals are discussed more in detail, namely: to establish conditions which will allow the patient to maintain a dentition without further breakdown of the periodontium; to reduce pocket depth to establish an anatomy in the dentogingival region which with proper maintainance care will prevent the re-establishment of the subgingival infection; to gain attachment as a result of treatment; to assess the effect of a certain chemotherapeutic agent on periodontal disease.     

《口腔医学》杂志2007年度有关信息的分析

目的通过对《口腔医学》2007年全年文献的回顾和分析,了解我国口腔临床医学的研究现状。方法阅读2007年《口腔医学》全年的文献,对各种信息进行了分类汇总,根据设计类型对临床一次性文献进行了分类,并对其中的试验性研究文章进行质量分析。结果《口腔医学》2007年全年的一次性文献274篇,基础和临床文献分别为108和166篇,以临床文献为主(60.58%)。在临床研究文献中,属于观察性、分析性和试验性的文献分别为97、9和60篇,观察性文献所占比例为36.14%,高于以往的报道。60篇观察性文献中,全都设有对照;统计方法应用得当者44篇;真正做到随机、盲法的分别只有4和2篇。结论我国口腔临床方面的研究水平近年来提高明显,但设计的科学性方面有待提高。     

口腔医学专业本科毕业生就业现状的调查分析和教育思考

目的研究口腔医学专业的教学如何面向市场,推出令用人单位满意的人才。方法采用问卷调查的方法对浙江省内有代表性的19家包含口腔医疗服务单位进行了调查,同时进行大学生就业心态调查问卷调查。结果医学生的就业心态出现多元化;毕业生不再一味追求高学历,更多的人选择了先就业后进修的道路。大多数用人单位着眼于提高医务人员的服务水平和质量,对毕业生的综合素质有了更高的要求。结论学校要尽力拓宽毕学生的就业渠道,提供更多的就业信息,树立面向基层的观念。     

Experimental evidence of formation of imines in the course of reduction of hydrazones

The reduction of hydrazones is generally suggested to proceed through a reductive cleavage of the nitrogen–nitrogen bond followed by a reduction of the carbon–nitrogen bond. This sequence of reduction processes is here supported for fluorenone (V) and benzophenone (VI) hydrazones as well as by a comparison of the reduction of fluorenone and benzophenone hydrazonium ions (I,III) with corresponding imines (II,IV). Another proof of the presence of imines as intermediates is the splitting of four-electron waves of hydrazones V and VI and hydrazonium ions I and VIII into two waves at pH < 2. This has been interpreted as due to differences in slopes dE_1/2/dpH and pK_a-values of protonated hydrazine derivatives on one side and corresponding imines on the other. In this pH-range imines formed in reductions of VI and VIII are reduced in a single two-electron wave, those of I and V in two one-electron steps. Fluorenone imine (II) is sufficiently stable to allow recording of time-independent current–voltage curves between pH 6 and 11. In this pH-range the imine (II) is reduced in two one-electron steps. Benzophenone imine (IV) has been found stable between pH 4.6 and 12. At pH 4.6–8 the reduction of the imine IV takes place in a single two-electron step, at pH 8–12 in two one-electron steps. Final proof of the initial cleavage of the N–N bond is presented by comparison with the reduction of nitrones.     

正常青年Monson球面半径的测量研究

目的测量正常青年Monson球面半径。方法选择60名(男30名,女30名)正常青年制取全口印模,应用立体摄影成像的原理与方法对Monson球面半径进行测量和统计学处理。结果Monson球面的半径平均为10.173 cm,大于理论值10.160 cm,差异有显著性(P<0.01);男、女性球面半径差异无显著性。结论本实验所得到的数据可作为全口义齿修复中记录颌位关系的一个参量。     

两种牙科切削陶瓷材料可切削性的比较

目的　对作者研制的一种新型含钙云母玻璃陶瓷PMC Ⅰ型陶瓷的可切削性能与VitaMKⅡ陶瓷进行定量比较 ,探讨PMC Ⅰ型陶瓷强度与其可切削性的关系。方法　采用钻孔实验方法 ,测定A、B、C、D4组不同晶化处理的PMC Ⅰ型陶瓷及VitaMKⅡ陶瓷材料 60 0s的钻孔深度 ,同时测定4组PMC Ⅰ型陶瓷的 3点抗弯强度。结果　VitaMKⅡ的钻孔深度为 0 71mm ;4组PMC Ⅰ型陶瓷的钻孔深度分别为 0 88mm、1 40mm、0 40mm和 0 90mm。其中 ,B组样品与其余组别及VitaMKⅡ陶瓷的差异有显著性 (P <0 0 5)。 4组PMC Ⅰ型陶瓷的 3点抗弯强度分别为 1 37 7、2 1 0 2、1 1 8 0和 1 0 6 0MPa。结论　新型PMC Ⅰ型切削陶瓷的可切削性已能够满足临床要求     

Electrodeposition of bilayers of dithiols

We report an electrochemical method to form a bilayer of dithiol. The cyclic voltammogram of the oxidative deposition of an aromatic dithiol on gold from an alkaline aqueous solution reveals two current peaks separated by more than 400 mV. The integrated charge of the oxidative current peak (B) at the most positive potential is twice that of the other oxidative current peak (A). These two oxidative current peaks were characterized by differential capacitance and electrochemical quartz crystal microbalance (EQCM) measurements. A decrease of the capacity by a factor of two, and an increase of the EQCM frequency change by a factor of two were observed when the potential was scanned from a value where only the first oxidative peak (A) is obtained, to a potential where both oxidative current peaks (A and B) are obtained. Infrared spectra show that the aromatic dithiols adsorb vertically at potentials corresponding to the current peak A and they become tilted for potentials corresponding to the current peak B. The simple relationships between the properties of the two oxidative current peaks are found to be compatible with a step-wise oxidative deposition of a bilayer of dithiol.