用激光共聚显微镜研究菌斑生物膜的结构

目的：研究菌斑生物膜的结构。方法：从牙齿表面获得完整的菌斑生物膜标本,运用激光共聚焦显微镜对其进行断层扫描和分析。结果：菌斑生物膜是由分布不均匀的细胞、基质和空隙构成的复杂结构。结论：应用激光共聚焦显微镜技术研究菌斑生物结构是一种可行的方法。     

菌斑生物膜原位干预模型的建立

目的 通过对原位菌斑生物膜发育过程及早期成熟菌斑生物膜的观察,探讨所建立的菌斑生物膜模型用于菌斑化学干预研究的可能性.方法 建立原位菌斑生物膜模型,运用激光共聚焦扫描显微镜结合荧光染色技术观察原位菌斑生物膜0～48 h的发育过程及48 h菌斑生物膜的活性和厚度.结果 可观察到0～48 h菌斑生物膜从无到形成到成熟,细菌排列趋于密集,菌斑厚度逐渐增加的过程.48 h的菌斑生物膜活性和厚度可检测.结论 建立的菌斑生物膜模型可观察原位菌斑的形成过程、形态及活性,适用于菌斑化学干预的研究.     

龋病病因相关因素的激光扫描共聚焦显微镜研究

牙菌斑生物膜作为细菌生长的微环境,在龋病形成和发展中起重要作用;口腔环境中相关因素如口腔黏膜中钙离子含量等与龋病也有一定关系。利用新兴的激光扫描共聚焦显微镜对菌斑生物膜及其他相关因素进行研究,取得了一系列新的进展,本文就此领域的相关问题作一综述。     

龋齿、牙周炎患牙和健康牙的菌斑生物膜特征

目的研究牙面菌斑生物膜特征与口腔疾病的关系。方法选择牙周健康而牙冠严重龋坏的龋齿5颗、无龋损而极度松动的牙周炎患牙6颗及正畸原因拔除的健康牙4颗,在扫描电镜下,观察分析龈上、龈下及移行生态区的菌斑生物膜特征。结果龋齿、牙周炎患牙和健康牙的牙面均观察到细菌混合物组成的菌斑生物膜,健康牙菌斑生物膜以球菌为主,放线菌和短杆菌少量;龋齿牙的龋坏处为坏死组织和细菌,龋边缘及龈沟处的球菌和短杆菌较健康牙多;牙周炎患者牙菌斑生物膜的细菌种类多,在龈上、龈下移行处可见典型的玉米棒状菌斑或以杆菌为主的紧密附着菌斑,龈下可见球菌、杆菌、梭菌及螺旋体等构成的复杂菌斑。结论龋齿、牙周炎患牙和健康牙菌斑生物膜细菌组成、集聚秩序和立体结构不同,菌斑生物膜的形成与细菌的附着、集聚、生长有关,也与局部病变密切相关。     

荧光原位杂交观察口腔原位菌斑中链球菌和具核梭杆菌的动态变化的研究

[摘要] 目的 观察口腔原位菌斑形成过程中链球菌和具核梭杆菌的动态变化。方法 专业洁治后,7个志愿者佩戴可形成口内菌斑生物膜以供原位菌斑研究的上颌装置,分别佩戴12 h、1 d、2 d、3 d、5 d后,取下样本,与链球菌和具核梭杆菌的特异性寡核苷酸探针进行荧光原位杂交,于激光共聚焦显微镜下观察菌斑生物膜的形成过程及2种细菌在菌斑形成发育中的分布及比例。结果菌斑生物膜厚度由5.26μm逐渐发育增加为46.93μm。12 h细菌仅形成平铺片状,链球菌占绝大多数,未见具核梭杆菌;此后细菌排列趋于密集,菌斑厚度逐渐增加,最后形成团块状菌斑。链球菌在2、3 d菌斑中比例下降;具核梭杆菌在5 d菌斑中比例比3 d上升107%。结论 链球菌在早期菌斑中为优势菌,具核梭杆菌在菌斑发育中期数量逐渐增加。2种细菌在菌斑形成中起到重要作用。     

激光共聚焦显微镜研究clpP基因缺失对变形链球菌生物膜耐酸陛的影响

目的：应用激光共聚焦显微镜观察clpP基因对变形链球菌生物膜耐酸性的影响。方法：将变形链球菌标准株UAl59和它的clpP基因缺陷株分别做成预酸化和致死酸化处理的菌液,接种于刻有宽500txm深500μm沟的羟基磷灰石圆片上厌氧培养12h。培养后取出圆片,所有圆片均在处理后立刻进行荧光死、活菌斑染色并行共聚焦观察。测算活菌厚度、面积及荧光强度占总菌斑的百分比,应用SPSS15．0统计软件,采用方差分析及均数两两比较分析clpP基因缺失对细菌生长及耐酸能力的变化。结果：共聚焦显微镜下,clpP基因缺失菌株所形成的生物膜菌斑厚度略薄于标准菌株（P〈0．05）,经过预酸化处理和致死酸处理后clpP基因缺失菌株所形成的生物膜菌斑厚度显著薄于标准菌株（P〈O．01）,而且活菌百分比显著低于标准株（P〈0．01）。结论：共聚焦显微镜下clpP基因可以显著地降低变形链球菌的耐酸能力,并一定程度地降低变形链球菌的生长能力。     

人正常及炎症牙髓中炎症信号受体TLR4表达的研究

目的:研究人正常及炎症牙髓组织中炎症信号受体TLR4的表达特点,探讨其在牙髓和根尖周组织炎症中的可能作用。方法:采用激光共聚焦扫描显微镜和免疫荧光技术,检测正常及炎症牙髓TLR4的表达情况。结果:正常牙髓组织中未发现TLR4免疫阳性细胞,炎症牙髓组织病灶处TLR4表达强阳性。正常组平均荧光强度为28.80±2.57,炎症组为258.12±24.51(P<0.001)。结论:与正常牙髓组织相比,炎症牙髓组织TLR4表达显著增强,提示其可能参与牙髓组织炎症过程。     

Fluoride uptake from restorative dental materials by human enamel

abstract – The purpose of the study was to determine the uptake in vitro of fluoride from restorative materials by tooth ename1 and whether prior etching of the ename1 causes a change of uptake. The outermost layer of the labial surface of extracted canines was removed by grinding and the enamel was covered with five different fluoride-containing materials; a silicate, a composite resin, an amalgam, a silicophosphate, and a polycarboxylate luting cement. The material was either removed immediately or after storing the tooth in distilled water. The fluoride content was determined using a sensitive physical method based on the ¹⁹F (p, αy) ¹⁶O reaction. In addition, the fluoride content of enamel after etching for different periods of time and of etched enamel which had been in contact with silicate cement was determined. The mean fluoride content of uncovered interior ename1 was 226 parts/10⁶. All materials, except the composite, increased clearly the fluoride content of the underlying enamel. Etching of interior enamel also increased the fluoride values. No difference could be shown in fluoride uptake from silicate and composite resin between etched and unetched enamel.     

三类常用牙体充填材料界面微渗漏的激光扫描共聚焦显微镜观测

目的 观察银汞舍金、复合树脂和玻璃离子三类常用牙体充填材料在体外充填后的微渗漏情况.比较材料的边缘封闭性.方法 选取新鲜无龋前磨牙,备洞,充填材料,37℃水浴条件下0.1%罗丹明B荧光染料浸泡,激光扫描共聚焦显微镜测量荧光剂渗入深度,定量评价微渗漏程度.结果 三类材料与牙体界面均有不同程度的荧光染料渗入,渗漏程度由小到大依次为玻璃离子(23.63±3.06μm)、银汞合金(31.68±10.97μm)、复合树脂(32.86±11.67μm).玻璃离子与复合树脂相比有显著差异,在亚组中,使用玻璃离子预处理与银汞直接充填有显著差异,自酸蚀与全酸蚀粘结树脂也有显著统计学意义.其余各组比较无显著差异.结论 三类材料中玻璃离子与牙体界面的微渗漏最小;使用玻璃离子预处理后获得的边缘封闭性优于银汞直接充填;全酸蚀复合树脂与牙体的密合性较自酸蚀更佳.     

种植体愈合帽表面细菌生物膜结构初探

目的：研究口腔内纯钛种植体短期内表面细菌生物膜的结构，并探讨细菌生物膜结构与口腔卫生环境的相关性。方法：从12例种植患者获得术后6周复诊时取下的12枚完整的ITI种植体愈合帽，运用激光共聚焦显微镜对愈合帽表面生物膜的结构、分布等性质进行定性观察和定量分析，并分析了与牙菌斑指数的关系。结果：种植术后6周的12枚种植体愈合帽表面均广泛存在细菌生物膜，但分布不均，与愈合帽表面的位置有关。生物膜的厚度及范围与牙菌斑指数呈正相关。结论：术后短期内种植体愈合帽表面细菌生物膜的结构与口腔临床指标间存在一定的相关性。     

应用牙本质屏障法测定牙齿充填材料体外细胞毒性

目的:探讨牙本质屏障法用于牙齿充填材料体外细胞毒性试验测定的特点。方法:低速锯片切新鲜拔除的磨牙,获取紧邻牙髓的颊侧牙本质片,选择通透值相近的牙本质片作为牙本质屏障,制作细胞毒性体外测试装置,用此装置测定氧化锌丁香油水门汀、复合树脂、玻璃离子水门汀、氢氧化钙水门汀、磷酸锌水门汀及阴性对照材料和阳性对照材料的细胞毒性,同时用传统的浸提液法测定这5种材料的细胞毒性。结果:牙本质屏障法测定的5种材料的细胞相对活性(%)分别为89.1±3.6、81.8±3.7、96.4±2.8、96.2±1.8、74.5±2.8;浸提液法测定的5种材料的浸提原液细胞相对活性(%)分别为35.6±5.2、72.9±4.3、91.5±1.3、90.2±2.6、59.3±2.6。结论:牙本质屏障可以显著减少充填材料对细胞的毒性作用,牙本质屏障法更能反映充填材料的体内细胞毒性。     

盐酸米诺环素软膏局部应用对龈下菌群的影响

目的:研究20 g/L盐酸米诺环素软膏局部应用后,牙周袋内龈下菌丛的变化。方法:重度慢性牙周炎患者洁治后,在牙周袋内置入20 g/L盐酸米诺环素软膏0.05 mL,于置药前及置药后2、6、120 h分别取龈沟液,用高效液相色谱法(HPLC)检测其中米诺环素浓度,并取龈下菌斑用细菌活力试剂盒染色,激光扫描共聚焦显微镜(LCSM)观察龈下菌群死活菌的比例及球菌、活动杆菌、螺旋体的比例变化。结果:龈沟液中盐酸米诺环素浓度在置药后120 h仍>1μg/mL,置药后龈下菌斑中死菌比例明显较置药前增高,置药后的龈下菌斑中球菌比例明显上升,活动杆菌及螺旋体比例显著下降。结论:20 g/L盐酸米诺环素软膏是一种缓释制剂;在一定浓度下既有抑菌作用又有杀菌作用;龈下菌斑的死活菌染色结合LCSM镜下检查可作为牙周健康状况及预后的评价方法。     

Nordic dentists' opinions on the safety of amalgam and other dental restorative materials

The safety of amalgam and other restorative materials has caused concern among dental patients in recent years. The aim of this study was to obtain information on dentists' perceived competence in handling different filling materials and their opinions on the safety of these. A random sample of practising dentists in Denmark, Finland, Norway, and Sweden received a mail question-naire in spring 1990. Answers were received from 1732 dentists (65%). The study showed that the respondents believed that their theoretic knowledge and clinical skills were generally at a high level regarding restorative materials. The risks of the side-effects of gold, ceramic materials, and glass ionomer were considered to be low by about 90% of the respondents. Amalgam was considered to be significantly more hazardous by the Swedish respondents than the others. Interestingly, composite was considered to be associated with a high risk of side-effects by about half of the dentists in all Nordic countries. The dentists' opinions were not found to be greatly influenced by their sex, age, or place of residence but rather by their country and service sector. Against the background of the present lack of scientific evidence on the hazardousness of amalgam or other restorative materials for patients' general health, these findings indicate that dentists are influenced by discussions in the mass media about dental treatment and materials and, of course, by the guidelines given by the health authorities in their own countries. Few dentists were shown to be concerned about occupational risks associated with the use of amalgam, and they had not had their own amalgam fillings replaced. Thus, Nordic dentists seem prepared to continue to use amalgam as one of several dental restorative materials while waiting for technically and biologically more satisfactory ones.     

口腔修复材料界面对菌斑生物膜的影响

随着口腔医学的发展,各种口腔修复材料被广泛应用于临床治疗中。修复材料不同的表面结构及化学性质会对细菌的黏附定植以及生物膜的发育成熟产生一定的影响。在唾液环境中,虽然获得性膜可在一定程度上弱化不同材料界面的固有特性,但材料界面的某些特性仍能通过远程作用力穿透获得性膜并作用于微生物的初始黏附,从而影响生物膜的发生发展。在生物黏附早期,材料界面主要通过各种力学因素从而对微生物黏附产生影响。此外,修复材料还可通过化学物质的释放来影响生物膜的代谢。复合树脂、玻璃离子黏固剂、陶瓷材料和金属材料是口腔常见的修复材料,探讨常见口腔材料界面对生物膜的影响机制,可为口腔材料的改性研发提供理论支持。     

牙菌斑生物膜模型的研究进展

牙菌斑生物膜是龋病和牙周病的主要致病因素,也是目前口腔微生物学和生态学研究的热点.研究者们建立了多种模型以研究菌斑生物膜的发生机制和发生过程.龈上菌斑和龈下菌斑的生存环境及其内的微生物群有明显差异,故模型系统也各不相同.龈上菌斑易于收集且其生存环境易于模拟,目前已有多种体内和体外模型被用于龈上菌斑生物膜的研究,而龈下菌斑生物膜模型的研究相对较少.本文就牙菌斑生物膜模型的最新研究进展作一综述.     

Adaptation of resinous restorative materials to acid etched enamel surfaces

abstract — The purpose of this paper was to study by means of scanning electron (SEM) and optical microscopy the adaptation of the low-viscous non-composite Nuva-Seal(r) and of the three high-viscous composite restorative materials Adaptic(r), Compocap(r) and Concise(r) to phosphoric acid etched enamel surfaces from symmetric areas of pairs of contralateral human permanent anterior teeth. The SEM study demonstrated that the two types of material equally well reproduce the details of the enamel surface; the light microscopic observations showed that the length and shape of resin tags in the enamel surface are independent of the materials examined. The observations seem to allow the conclusion that bonding of composite restorative resins to phosphoric acid etched enamel surfaces is not conditioned by the employment of an intermediate film of a low-viscous non-composite resin.