菌斑结构的美蓝和革兰氏染色观察

目的：在建立菌斑口内模型的基础上,了解菌斑形成的超微结构。方法：建立一种口内的菌斑模型,将菌斑标本制成半薄切片,分别用革兰氏和美蓝染色后光镜观察。结果：染色显示菌斑中含有球状菌、杆状菌以及丝状菌等细菌,其中部分细菌会出现坏死现象;革兰氏染色显示阳性菌大多为球状或杆状菌,呈散在分布;阴性菌多为丝状或弯曲状菌,分布呈丛状或簇状。结论：建立的菌斑模型较为接近天然菌斑结构,具有一定的应用价值。     

五倍子对菌斑生物膜内细菌的抑制作用

目的:应用人工口腔观察五倍子对菌斑生物膜内细菌的抑制作用。方法:采用液体二倍稀释法测定与致龋病关系较密切的4种细菌的最小抑菌浓度,并进一步在人工口腔中形成各实验菌的单一细菌菌斑生物膜,应用菌落计数技术观察五倍子水提取物对菌斑生物膜内细菌的抑制作用。结果:五倍子水提取物对变形链球菌、粘性放线菌、血链球菌、口腔链球菌的生长均有抑制作用,其中对变形链球菌、粘性放线菌和血链球菌的最小抑菌浓度(MIC)为64mg/ml,口腔链球菌为8mg/ml;不同浓度的五倍子水提取物对各实验菌形成的单一细菌菌斑生物膜均有一定的抑制作用,并呈浓度依赖性;即使采用大于MIC的浓度,也不能把釉质表面形成的生物膜完全抑制,釉质表面仍有细菌生长。结论:五倍子水提取物对菌斑生物膜内细菌具有良好的抑制作用;与浮游细菌相比,生物膜中的细菌对五倍子水提取物具有较强的抵抗力。     

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.     

蔗糖对人早期牙菌斑形成的影响

目的 :观察蔗糖对早期牙菌斑形成的影响。方法 :利用扫描电镜观察在同一个体体内含漱含蔗糖和不含漱蔗糖溶液所形成的早期牙菌斑的超微结构。结果 :含漱蔗糖溶液后 ,2 4h内牙菌斑形成的速度明显增快 ,菌斑内的细菌被粘稠的基质所包裹 ,菌斑结构致密 ,3天时菌斑中仍以球菌为主。不含漱蔗糖溶液形成的菌斑 ,基质稀少 ,细菌排列松散 ,在 3天时 ,菌斑表面以丝状菌为主。结论 :蔗糖可能通过影响细菌的粘附加速菌斑的形成速度 ,并可能对牙菌斑的细菌构成有一定的影响。     

人工菌斑生物膜的研究方法

菌斑生物膜是人类龋病和牙周病的主要致病因素,为当前口腔细菌生态学的研究热点。由于口腔环境不易控制和菌斑生物膜极其复杂,直接对自然菌斑生物膜研究存在困难。近年来利用人工菌斑生物膜研究获得了许多可喜的结果,本文就其体外培养模型及基本生物量、结构和组成、活性的分析方法作一综述。     

蔗糖对人早期牙菌斑形成的影响

目的：观察蔗糖对早期牙菌斑形成的影响。方法：利用扫描电镜观察在同一个体体内含漱含蔗糖和不含漱蔗糖溶液所形成的早期牙菌斑的超微结构。结果：含漱蔗糖溶液后，24h内牙菌斑形成的速度明显增快，菌斑内的细菌被粘稠的基质所包裹，菌斑结构致密，3天时菌斑中仍以球菌为主。不含漱蔗糖溶液形成的菌斑，基质稀少，细菌排列松散，在3天时，菌斑表面以丝状菌为主。结论：蔗糖可能通过细菌的粘附加速菌斑的形成速度，并可能对牙菌斑的细菌构成有一定的影响。     

牙周炎患者附着菌斑和非附着菌斑的比较

选取２５名牙周炎患者，采用不同的取菌方法，分别采取其龈下附着菌斑和非附着菌斑的标本，通过暗视野显微镜和刚果红涂片染色进行观察，结果显示：无论是暗视野显微镜还是刚果红涂片观察，龈下附着菌斑和非附着菌斑的细菌组成都是明显不同的；附着菌斑中，球菌占较大比例，可动菌和螺旋体相对较少，而非附着菌斑中的可动菌和螺旋体则占主要地位，球菌相对较少，进一步证实了龈下非附着菌斑是与牙周病关系最为密切的微生态区，也是牙     

慢性牙周炎龈下菌斑中福赛斯坦纳菌的检测

目的检测慢性牙周炎患者和牙周健康者龈下菌斑中福赛斯坦纳菌的数量和所占比例,探讨福赛斯坦纳菌与牙周炎发生发展的关系。方法采集经常规聚合酶链反应（PCR）法检测福赛斯坦纳菌为阳性的61例慢性牙周炎患者和12例牙周健康者的龈下菌斑,应用TaqMan实时荧光定量PCR法对菌斑的细菌总量和福赛斯坦纳菌的数量进行定量检测,构建含有福赛斯坦纳菌和真细菌靶基因的重组质粒,建立定量标准。结果本研究设计的引物和探针具有良好的特异性和敏感性;慢性牙周炎患者病变位点的福赛斯坦纳菌数量和细菌总量均高于牙周健康者的健康位点,且福赛斯坦纳菌在龈下菌斑中的比例也比健康位点高（P<0.05）;龈下菌斑的细菌数量与探诊深度呈正相关（P<0.001）;龈下菌斑中福赛斯坦纳菌所占比例在不同的探诊深度间无统计学差异（P>0.05）。结论龈下菌斑中福赛斯坦纳菌的数量与牙周状况有密切关系,实时荧光定量PCR法是研究牙周病病因及治疗方法的有效手段。     

人工菌斑生物膜的研究方法

菌斑生物膜是人类龋病和牙周病的主要致病因素，为当前口腔细菌生态学的研究热点。由于口腔环境不易控制和菌斑生物膜极其复杂，直接对自然菌斑生物膜研究存在困难。近年来利用人工菌斑生物膜研究获得了许多可喜的结果，本文就其体外培养模型及基本生物量、结构和组成、活性的分析方法作一综述。     

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。     

Development of plaque on enamel

Intact human enamel was used to study the development of dental plaque. This procedure involved placing cylinders of surface enamel in an appliance that was worn by one subject up to seven days. By using a technique of slight demineralization of the enamel, pellicle and plaque could be sectioned along with the enamel for light and transmission microscopy. Scanning electron microscopic and microbiologic studies were also performed on the specimens. Microbiologic investigation of two day old samples from the one individual revealed the presence of streptococci and a smaller number of Neisseria. Streptococcus sanguis was the predominant streptococcal species. Early samples of dental plaque appeared to have more desquamated epithelial cells than seven day old plaques. Electron micrographs suggest that bacteria may digest these epithelial cells. An apparent distinction between bacteria adjacent to the enamel and bacteria adsorbed to the surface of the enamel was. noted. Adsorbed bacteria appeared to alter their morphology and excrete an extracellular material which later formed a pellicular layer. Seven day old samples characteristically showed an alignment of rods superior to the adsorbed cocci. The formation of dental plaque on enamel cylinders may better simulate "in vivo" conditions than previous techniques.     

Studies on artificial dental plaque. Preliminary observation on the morphology of developing artificial dental plaque

This paper introduced a new method which was used to study the formation of dental plaque in vitro. From this investigation, it can be regarded that artificial dental plaque is similar to natural dental plaque in structure. In the 1st day, artificial dental plaque was mainly coccal shaped bacteria adherent on the tooth enamel. At the third day, the number of filaments and rods increased obviously, and in 5th and 7th day plaques, main bacteria were filaments, with a few rods and cocci, and the special palisade and corn cob structures were occurred. The morphology of 2-week, 3-week and 4-week plaque were almost the same, but denser in structure.     

Induction and 3D reconstruction of caries-like lesions in an experimental dental plaque biofilm model

The aim of this study was to examine an in vitro dental plaque model for volumetric assessment and 3D reconstruction of experimentally bacterial induced caries-like lesions. Twenty-three extracted, impacted human molars were coated with a varnish leaving a 3 x 3 mm window on the smooth surface. The teeth were coated with human saliva and Streptococcus sobrinus 6715 adhered onto the enamel via a sucrose dependent mechanism. The coated teeth were incubated for 1, 7, 14 and 28 days. At the end of each incubation period microhardness was measured on three sectioned teeth of each incubation period at the enamel surface and at 450 and 750 microm depth perpendicular to the enamel surface. The enamel surface was investigated by scanning electron microscopy (SEM) prior to embedding and serial sectioning of 12 other teeth. The serial sections were studied with polarization light microscopy to investigate subsurface demineralization. The outlines of the caries-like lesions were then traced consecutively on transparencies, digitized and three-dimensionally reconstructed to demonstrate the expansion of the lesion into enamel for volumetric assessment. Microhardness was significantly reduced on the enamel surface after 7, 14 and 28 days incubation. The SEM investigation showed a surface demineralization with dissolution of the prism cores after 28 days incubation. Polarization light microscopy demonstrated caries-like lesions with an irregular expansion into enamel. The results demonstrate that the described method produces caries-like lesions which can be used for further experimental studies regarding demineralization and remineralization processes.     

十二烷基硫酸钠抗牙菌斑作用的实验研究

十二烷基硫酸钠（ｓｏｄｉｕｍｄｏｅｃｙｌｓｕｌｆａｔｅ，ＳＤＳ）常作为去垢剂广泛地应用于牙膏之中。已证实ＳＤＳ与羟基磷灰石（ＨＡ）有高度亲合力，通过ＳＤＳ与ＨＡ的结合，干扰蛋白质对ＨＡ的吸附，从而影响牙面获得性膜的形成。为进一步了解ＳＤＳ的抑菌和抗菌斑作用，本研究利用口腔恒化器和扫描电镜及同位素标记液闪检测技术，对ＳＤＳ的抗菌斑作用进行了观察。结果显示，经ＳＤＳ处理后的牙釉质表面没有成熟的牙菌斑形成，仅有少数细菌散在附着，其放射性明显少于对照组。提示ＳＤＳ具有抗菌斑作用，是牙膏中的天然抗菌斑成分之一。     

Fluoride profiles in dental plaque in vivo formed on fluoride pre-treated human enamel

Using a novel device capable of generating plaque in vivo on a natural enamel substrate, it has been possible to determine fluoride profiles from the saliva-plaque interface towards the enamel surface. Fluoride profiles in dental plaques tended to fall from the saliva-plaque interface towards the enamel. The device also offered the possibility of examining fluoride distributions after pre-treatment of the enamel with fluoride in vitro. Fluoride profiles were determined in plaque generated in vivo on enamel surfaces, which had been previously treated with a 900-ppm fluoride solution. The results showed the previously reported fall from the plaque surface, but in addition, a further rise towards the enamel surface was seen. The data imply that enamel loaded with fluoride can release some of this fluoride back into the plaque and may act as a fluoride reservoir.     

The effect of sucrose application frequency and basal nutrient conditions on the calcium and phosphate content of experimental dental plaque

A reduced pool of calcium in dental plaque would be expected to increase the ability of plaque fluid to dissolve the underlying enamel when the pH falls during sugar exposure. We have examined the relationship between frequency of sugar application and Ca and P(i) concentrations in artificial mouth plaque microcosm biofilms. Ten plaques were grown simultaneously from a human saliva inoculum using a continuous flow of simulated saliva, DMM, supplemented with either urea or glucose to modulate the resting pH. In addition the plaques received sucrose applications of varying frequency: 12-, 8-, 6-, or 4-hourly, or not at all. After 15 days the plaques were sampled by taking 4 full-thickness specimens of each, and acid-extractable Ca and P(i), and alkali-soluble protein and carbohydrate were determined. Ca and P(i) concentrations were in a range comparable with those in human plaque, except in the DMM + urea plaque receiving no sucrose, when concentrations were higher. Plaque Ca concentration decreased significantly as sucrose application frequency increased. Increasing sucrose application frequency also reduced the protein, i.e. the cell biomass, content of the plaques and, in the case of DMM + urea plaques, increased the water-insoluble hexose content, presumably extracellular polysaccharide. Reduced biomass was partly due to the bulking of plaque with extracellular polysaccharide, but the marked effect of urea on polysaccharide formation is not understood. This study shows that increasing frequency of sugar application alters dental plaque by reducing its mineral protection capacity.     

恒磨牙窝沟菌斑结构的研究

目的比较有龋窝沟和无龋窝沟的菌斑结构。方法首先将拔除的双尖牙或磨牙进行双固定,通过窝沟,颊舌向连续切两张牙片,锇酸固定后,一张牙片做显微放射照相分析,确定有龋和无龋牙各5颗,另一张牙片用环氧树脂包埋;部分磨除表层的环氧树脂以暴露牙本质和釉质,10％EDTA脱钙,将菌斑包埋、切片,透射电镜观察。结果有龋窝沟和无龋窝沟的菌斑结构有明显的区别：有龋窝沟菌斑中细胞成分较多,细胞形态变化较多,多数细胞形态完整、包膜清晰,细胞间的基质成分较少,在基质中可见大量的膜样结构;无龋窝沟菌斑中细胞成分较少,细胞形态变化较少,多为圆形,细胞间的基质成分较多,细胞之间可见明显的基质间隔。二者也有相同的特点：菌斑与釉质界面上有连续的高电子密度的条带,未见明显的细胞分裂,无龋窝沟菌斑在整个菌斑的不同区域均可见到细胞壁的增厚、细胞内钙化、细胞内空泡变性等现象,并且明显多于有龋窝沟菌斑。结论有龋窝沟菌斑和无龋窝沟菌斑的结构有显著差别,有龋窝沟菌斑中细胞数量多,体积大。     

Characterization of human dental plaque formed on hydrogen-ion-sensitive field-effect transistor electrodes

The purpose of this study was to evaluate (with scanning electron microscopy and microbiological characterization) the bacterial deposits which accumulate on hydrogen-ion-sensitive field-effect transistor electrodes (pH-ISFET) under conditions normally employed for telemetric monitoring of changes in human dental plaque pH. Electrodes were mounted in a carrier appliance which was worn for two, four, and six days. The plaque pH response to a sucrose solution increased with the age of the plaque, as expected from previous studies. After two days, the electrode was shown to be almost completely covered with cocci. At days 4 and 6 there was a dramatic increase in the number of rods present in the plaque. Adjacent enamel surfaces showed similar accumulations of bacteria. The total number of bacteria which had accumulated per unit area by day 4 was very similar for the electrode and enamel surfaces. On both surfaces the plaque contained approximately 25% streptococci, and the dominant species was Streptococcus sanguis (approximately 75%). The plaque which accumulated on pH-ISFET electrodes could not be distinguished visually or microbiologically from that which formed on control enamel surfaces.     

粘贴含氟正畸托槽后菌斑和唾液中氟离子的变化

目的 测定粘贴含氟正畸托槽后,口腔内菌斑及唾液氟离子浓度的变化,探讨采用含氟正畸托槽预防牙釉质脱矿的意义.方法 选择10名志愿者,口腔内粘贴含氟正畸托槽.用离子选择性氟电极测定口腔内菌斑及唾液氟离子浓度,并与粘贴托槽前的基线水平相比较.结果 粘贴含氟正畸托槽后,菌斑及唾液中氟浓度均升高,唾液氟浓度持续3天高于基线水平,...