表面活性剂对S．sobrinus 6715在实验性获得性膜粘附影响的体外研究

通过细菌对羧磷灰石（ＨＡ）表面形成的实验性获得性膜粘附的实验模式，比较了５种表面活性剂对Ｓ．ｓｏｂｒｉｎｕｓ６７１５粘附的影响。结果表明，所实验的５种ＳＡＡ对Ｓ．ｓｏｂｒｉｎｕｓ６７１５对原位形成的葡聚糖的粘附无明显影响，而阳离子含氟表面活性剂ＺｏｎｙｌＦＳＣ在０．１％～０．２％浓度时对粘附的菌细胞有明显的解吸作用。     

粘性放线菌对牙面粘附机理的研究──Ⅰ．实验性全唾液获得性膜蛋白组份的分离纯化

采用羟基磷灰石柱层析形成实验性获得性膜的体外模型，研究全唾液获得性膜蛋白的组成成份。结合离子交换及分子筛层析分离获得８种获得性膜的蛋白成份。根据层析用谱、等电点、氨基酸组成及免疫扩散分析，其中６种可确定为富脯糖蛋白、淀粉酶、ＳＩｇＡ、酸性富脯蛋白、富酪蛋白及富组蛋白。实验结果表明唾液中的蛋白质选择性吸附到羟基磷灰石上，分离纯化的获得性膜蛋白为筛选促进致龋菌在牙面粘附的唾液蛋白受体提供了直接的研究材料。     

含氟表面活性剂对变形链球菌和粘性放线菌对实验性唾液膜粘附的影响

许多含氟表面活性剂已显示了明显的控制菌斑作用．本文研究了5种表面活性剂对变链菌JBP和粘性放性菌LY-7对唾液实验性膜粘附的影响．结果表明，5种表面活性剂都不同程度地减少了JBP和LY-7的粘附，有的还对已粘附的细菌有一定的解吸作用．提示表面活性剂控制菌斑的作用与其减少细菌粘附有关．     

纤维粘接蛋白和脂磷壁酸对口腔链球菌粘附的影响

本文采用体外粘附实验的方法，分析了菌体表面分子脂磷壁酸与唾液及牙表面获得性膜中的生物活性物质纤维粘接蛋白对口腔链球菌粘附的影响，结果发现脂磷壁酸可抑制变链菌对含纤维粘接蛋白的人工获膜的粘附，支持了脂磷壁酸与纤维粘接蛋白相互作用可促进口腔链球菌粘附的观点。     

金属表面的蛋白吸附的机理研究现状

金属表面与组织之间的相互作用是一个相当复杂的过程，金属表面在与组织的最初的接触时在种植体表面形成一层蛋白膜，而该膜可以影响随后的组织反应，本文综述了金属表面与蛋白相互作用可能有的几种方式，不同金属表面的蛋白吸附的种类人及钛合金表面特性，以及由此引起的特殊的血清蛋白吸附行为，及可能的机理和金属表面蛋白吸附的研究现状及意义。     

唾液获得性膜对不同桥体材料表面自由能的影响

目的：评价唾液获得性膜对不同桥体材料表面自由能的影响。方法：采用接触角测量仪检测4种桥体材料(Co—Cr合金、Au—Pt合金、纯Ti以及Vita95瓷)表面形成唾液获得性膜前后试件的接触角并计算表面能。结果：制备唾液获得性膜后所有受测材料的表面自由能极性分量升高，自由能总量趋于一致。结论：唾液获得性膜会改变修复材料的表面属性，使不同材料表面自由能之间的差异减小。     

变形链球菌对唾液成份的选择性结合

本文研究了吸附于羟基磷灰石表面的唾液成份促进变形链球菌粘附的能力。结果表明:下颌唾液明显地促进了 S.mutans,S.cricetus 和 S.rattus 菌株的粘附,而对 S.sobrinus 菌株的粘附无影响。实验菌株对层析分离的各唾液组分的粘附也展示了明显的差异。本实验结果说明变形链球菌与唾液成分相互作用的特异性,不同唾液成份促进了不同变链菌株的粘附,提示不同的变链菌株具有不同的粘结素,它们粘附到实验性唾液膜的不同受体上。     

粘性放线菌对牙面粘附机理的研究：Ⅰ.实验性全唾液获得性 …

采用羟基磷灰石柱层析形成实验性获得性膜的体外模型，研究全唾液获得性膜蛋白的组成成份。结合离子交换及分子筛层分离获得８种获得性蛋白成份。根据层析图谱，等电点，氨基酸组成及免疫扩散分析，其中６种可确定为富脯糖蛋白，淀粉酶，ＳＩｇＡ，酸性富脯刷白，富酷蛋白及富组蛋白。     

人类高分子量唾液粘蛋白抗釉质脱矿的体外超微观察

唾液获得性膜是唾液蛋白对牙釉质表面的选择性吸附 ,是一层非发育性的无细胞结构的薄膜 ,具有屏障保护作用。人高分子量唾液粘蛋白 (ＭＧ1)对羟基磷灰石 (ｈｙｄｒｏｘｙａｐａｔｉｔｅ,ＨＡ)有高度亲和力而成为获得性膜的主要成分之一。我们采用全唾液和纯化ＭＧ1分别在离体牙釉质表面形成获得性膜 ,观察此膜是否能减少有机酸对牙釉质表面的脱矿作用。1.材料和方法 :实验分 3组。第 1组为ＭＧ1组 ,将纯化ＭＧ1按 0 16ｇ/Ｌ溶于 10 7ｍｍｏｌ/ＬＮａＣｌ溶液中 ;第 2组为全唾液组 ,将收集的全唾液 4℃离心 (4 0 0 0ｒ/ｍｉｍ ,15ｍｉｎ) ,…     

变链球菌表面蛋白分子结构中功能区的研究

变链球菌表面蛋白与牙面获得性膜上唾液蛋白成份结合，促进了变链球菌在牙面的附着。粘附功能区可能主要位于表面蛋白分子Ｎ端包含Ａ区的片段中，亦可能存在于中间区域的Ｐ区及附近氨基酸顺序中，但不能排除分子Ｃ端参与粘附的可能。对表面蛋白粘附功能区的研究，有助于从分子水平阐明变链球菌在牙面粘附的机理，为龋病的防治提供理论依据。     

Experimental salivary pellicles on the surface of orthodontic materials.

The purpose of this study was to define the composition of salivary pellicles that form on the surfaces of orthodontic materials and to further investigate whether qualitative differences exist between the composition of adsorbed salivary pellicles that form on 3 different orthodontic materials: stainless steel bracket metal, elastomeric ligature ring, and bracket bonding resin. Experimental pellicles were formed by incubating these materials in fresh human parotid or submandibular-sublingual saliva for 2 hours. Pellicles were extracted with sodium dodecyl sulfate buffer and lyophilized. They were then subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting to identify the adsorbed salivary components. Remarkable differences in the profiles of pellicle components were found, dependent on the type of orthodontic materials. The pellicle components on the bracket metal were almost the same as those found on the elastomeric ligature ring. Salivary protein adsorption patterns to bonding resin showed different features. Distinct differences were also found between the surface-binding affinities of the same salivary proteins from different glandular salivas. These results may be explained on the basis that binding sites for specific proteins on the surfaces of the materials are covered by molecules of submandibular-sublingual saliva, probably mucins. The results of this study provide valuable information concerning initial bacterial adhesion to the surfaces of orthodontic materials, as well as information that could be used in the development of orthodontic materials with enhanced surface properties.     

Roles of salivary proteins in the adherence of oral streptococci to various orthodontic brackets

Knowledge of salivary pellicles on orthodontic brackets provides a better understanding of microbial adherence. The aim of this study was to analyze the effects of bracket pellicles on the adherence of Streptococcus gordonii and Streptococcus mutans. Bracket pellicles were formed by the incubation of 4 kinds of orthodontic brackets with unstimulated whole saliva for 2 hrs, and analyzed by electrophoresis, immunodetection, and amino acid analysis. Binding assays were then performed by the incubation of tritium-labeled streptococci with the pellicle-transfer blots and orthodontic brackets. The results showed that low-molecular-weight mucin, alpha-amylase, secretory IgA, acidic proline-rich proteins, and cystatins adhered to all kinds of brackets, though the amino acid composition of pellicles differed between bracket types. Some of these proteins increased the binding of S. gordonii to saliva-coated brackets. However, salivary pellicles decreased the binding of S. mutans. Collectively, salivary pellicles were found to play a significant role in the initial adhesion of oral streptococci to orthodontic brackets.     

Human minor and major gland saliva proteins and ability to mediate Actinomyces naeslundii adherence

Bacteria-binding components and the ability to mediate bacterial adhesion to the tooth surface have been thoroughly studied in major salivary gland secretions. Our knowledge on the bacteria binding activity in minor gland saliva is, however, limited. In this study, proteins were examined in parallel in minor (palatal, buccal and labial) and major (parotid and submandibular/sublingual) salivary gland secretions in one subject using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. The adherence of early colonizing Actinomyces naeslundii to pellicles formed from the secretions on hydroxyapatite beads was also examined. Amylase, IgA, proline-rich proteins and the high-molecular-weight glycoproteins, agglutinins, were detected in all saliva tested. Carbohydrate-reactive antibodies recognized the low-molecular weight mucin, MUC 7 in submandibular/sublingual saliva only. A. naeslundii strain 12104 adhered to all pellicles and especially to the buccal gland saliva pellicles. Strain LY7 adhered in highest numbers to the submandibular/sublingual saliva pellicles. It also bound in considerable numbers to parotid and palatal saliva pellicles but not to the ones formed from buccal and labial gland saliva. Our findings indicate that several bacteria-binding components are secreted in both minor and major gland saliva. The adherence-promoting ability of the various gland secretions differs, however.     

Interaction of salivary fibronectin with oral streptococci

Immunoreactive Fibronectin (Fn) has been demonstrated in stimulated human parotid saliva by western blot analysis and also found to be a component of the artificial tooth pellicles derived from hydroxyapatite (HA) beads coated with parotid saliva. Saliva depleted of gelatin-binding components showed a significantly lower degree of reactivity with anti-Fn antibodies than did the control saliva when tested by and enzyme-linked immunosorbent assay (ELISA). Depletion of gelatin-binding components from saliva was also found to affect the degree of saliva-mediated aggregation of four of the seven oral streptococci tested [Streptococcus mutans strains GS-5 and OMZ 176, S. sobrinus, and S. rattus]. Similarly, the adherence of the same four micro-organisms to the artificial tooth pellicles (derived form saliva which had previously been depleted of gelatin-binding component) was significantly inhibited (37-53%) when compared with the control saliva-coated HA beads. Pre-treatment of streptococci with 100 micrograms of soluble Fn also caused a 34-57% inhibition of adherence of the same oral streptococci to saliva-treated HA beads. Quantitation of Fn in human parotid saliva showed that the amounts of immunoreactive Fn varied form 2 to 6 micrograms/mL of parotid saliva. Furthermore, the Fn from parotid saliva was found to be adsorbed onto the bacterial surfaces, as demonstrated by immunofluorescence and ELISA. The presence of Fn in parotid saliva and its ability to bind to HA beads (artificial pellicles), in conjunction with the ability of soluble Fn to inhibit the adherence of streptococcal strains to the artificial tooth pellicles, suggest that the microbial ecology of the oral cavity may, in part, be influenced by the interactions mediated by salivary fibronectin.     

Probiotic bacteria affect the composition of salivary pellicle and streptococcal adhesion in vitro

Introduction:  The use of probiotic bacteria is increasing worldwide and at least some of them can transiently colonize the oral cavity. Several studies have shown that probiotic bacteria, which are often thought of in relation only to intestinal health, can also affect the oral ecology, but the mechanisms for this are largely unknown. The aim of this study was to investigate in vitro if the probiotic bacteria used in commercial products affect the protein composition of the salivary pellicle and the adherence of other oral bacteria.
Methods:  Salivary pellicle on hydroxyapatite and the adhesion of two oral streptococci, Streptococcus mutans and Streptococcus gordonii , were used as a model.
Results:  Probiotic bacteria that bound to saliva-coated hydroxyapatite reduced the adhesion of S. mutans but the inhibitory effect on the adherence of S. gordonii was weaker. Salivary pellicle protein composition was modified by all the strains tested. The modifications in the pellicle affected the adherence of S. mutans but not of S. gordonii . Two of the proteins missing from the pellicles made of saliva-treated with the probiotic bacteria were identified as salivary agglutinin gp340 and salivary peroxidase. All bacterial strains bound salivary agglutinin gp340. The ability of the probiotic bacteria to degrade peroxidase was demonstrated with purified bovine lactoperoxidase and two of the probiotic strains.
Conclusion:  This in vitro study showed that probiotic strains used in commercial products may affect the oral ecology by specifically preventing the adherence of other bacteria and by modifying the protein composition of the salivary pellicle.     

In vitro interactions of anionic and cationic surfactants with salivary fractions on well-defined solid surfaces.

Ellipsometry was used to study the interaction of one anionic (SDS) and one cationic (CTAB) surfactant with films adsorbed from six different salivary fractions obtained after fractionation of whole unstimulated saliva on a Superdex 200 Hiload gel filtration column. Experiments were performed on both hydrophilic silica and hydrophobic methylated silica surfaces. The results of this study indicate that the adhesive and cohesive properties of the films adsorbed from the individual fractions were strongly dependent on the surface characteristics of the substrates and that the outcome of protein/surfactant interactions was dependent on factors such as protein composition, surfactant charge, and substrate characteristics. These interactions probably involve replacement of the adsorbed proteins by surfactants or protein/surfactant complex formation. The anionic surfactant seemed to be more efficient in removing adsorbed salivary proteins than the cationic one.     

The phenomenon of salivary protein adsorption onto Streptococcus mitis ATCC 903 cells

It is thought that salivary proteins on bacterial cells have some influence on the adhesion of oral bacteria onto the surface of oral tissues and on bacterial aggregation. Initially, this study sought to examine the phenomenon of salivary protein adsorption to the surface of Streptococcus mitis ATCC 903 using 3H-labeled salivary proteins. We investigated the effects of hydrophobic level and lectin-ligand binding on adsorption of salivary proteins, and also the influence of cell surface components on adsorption. The results showed that the adsorption of salivary proteins was clearly reduced by the presence of Tween 20, LiCl, NaSCN, Hexadecane and some sugars. The adsorption was also affected by the pH level, and protease treatment or heat treatment of cells also decreased the volume of adsorbed proteins. Although the adsorption of proteins onto heat-treated cells was dramatically reduced by the presence of LiCl and NaSCN, the presence of sugars had little influence on this adsorption. These findings suggest that the main adsorption of salivary proteins is due to hydrophobic factors, and the heat-sensitive surface components of the cells had some relation to lectin-ligand binding. Therefore, it appears important to study the adsorption of salivary proteins onto cells since the salivary proteins on bacterial cells play an important role in their adherence to the saliva-coated oral tissues and bacterial aggregation.     

Adsorption of salivary and serum proteins, and bacterial adherence on titanium and zirconia ceramic surfaces

Objectives: The aim of this study was to determine the pattern of salivary and serum proteins present in pellicles formed on titanium (Ti) and zirconia ceramic (ZrO₂) surfaces, and the ability of bacterial cells to adhere to the experimental pellicles. In addition, the protein profiles and bacterial binding properties of pellicles on Ti and ZrO₂ were compared to those formed on hydroxyapatite (HA) surface.
Methods: The pellicles were formed in vitro by incubating the materials with whole saliva, serum or saliva+serum. Protein composition in each of the pellicles was investigated by SDS-PAGE and immunodetection. The adherence of radiolabeled Streptococcus mutans and Actinomyces naeslundii to uncoated surfaces and experimental pellicles was determined by means of scintillation counting. Statistical analyses were done using ANOVA and Tukey's test at significance level at P <0.05. In general, the electrophoretic analysis of the pellicles formed on HA, Ti and ZrO₂ revealed few qualitative differences of the composition of proteins of the pellicles formed on HA, Ti and ZrO₂ surfaces. Pellicle components identified included amylase, IgA, IgG, albumin, fibronectin and fibrinogen. The number of S. mutans cells adhered to uncoated Ti and ZrO₂ was significantly higher than those adhered to HA ( P <0.05). In contrast, lower number of A. naeslundii cells adhered to uncoated Ti and ZrO₂ than to HA ( P <0.05). However, the presence of saliva and saliva+serum pellicles greatly reduced the number of S. mutans cells bound to each of the surfaces. The data showed that Ti and ZrO₂ display similar pellicle protein composition and bacterial binding properties; however, significant differences were observed when both materials were compared to HA.     

Interactions of chlorhexidine with salivary films adsorbed at solid/liquid and air/liquid interfaces

Chlorhexidine is a cationic compound which has been shown to bind to salivary proteins and enamel through electrostatic interactions. The aims of this study were to investigate the interaction of chlorhexidine molecules with salivary films absorbed on solid surfaces with varying physico-chemical characteristics and to investigate the effect of different concentrations of chlorhexidine on the surface tension of saliva. The interactions between 0.2% chlorhexidine digluconate with films adsorbed from whole saliva were monitored by a Rudolph Thin-film ellipsometer equipped with a He-Ne laser (632.8 nm). The films were adsorbed on hydrophilic silica surfaces which were plasma cleaned or on methylated hydrophobic surfaces. Experiments of chlorhexidine adsorption on bare surfaces were also performed. The surface tension of mixtures of whole saliva with various concentrations of (0.1%, 0.2%, 1%) chlorhexidine was monitored with a tensiometer. The results show that chlorhexidine adsorbs on both types of studied substrates. Addition of the substance followed by rinsing caused a partial desorption of the adsorbed pellicles. Furthermore, at all studied concentrations chlorhexidine reduced the interfacial tension. There are indications that the amphiphilic characteristics of the molecule play an important role in the retention of the substance in the oral cavity.     

Saliva mediated adherence, aggregation and prevalence in dental plaque of Streptococcus mutans, streptococcus sanguis and actinomyces spp. in young and elderly humans

Salivary components in the pellicle mediate bacterial adherence to the tooth. Such components may also aggregate bacteria in saliva and prevent them becoming established in dental plaque. In the present study, the adherence and aggregation of Streptococcus mutans strain Ingbritt, S. sanguis strain 10556 and Actinomyces viscosus strain 19246 mediated by parotid and whole saliva from groups of young and elderly people were examined. Significant differences were found between test strains, salivary secretions and age groups. S. sanguis 10556 and A. viscosus 19246 generally adhered more strongly than S. mutans Ingbritt, which adhered better to pellicles from parotid saliva than from whole saliva. Strain 19246 bound in higher numbers to parotid saliva pellicles from elderly compared to young individuals. Strain 10556 adhered better to whole saliva than parotid saliva pellicles, and the difference was significant among the young individuals, indicating reduced adherence ability in elderly whole saliva. The streptococci were aggregated by parotid and whole saliva, and S. sanguis aggregation was less with whole saliva from the elderly than from the young participants. Besides a correlation between whole saliva aggregation of S. mutans and proportions of bacteria in plaque, no correlations were found for the individual binding properties of saliva and prevalence of bacteria in vivo. However, the level of saliva-mediated adherence in vitro was in the following order: S. mutans < Actinomyces S. sanguis, which corresponded to their isolation frequency in plaque. These findings emphasize the importance of initial adherence to salivary receptors in bacterial colonization on teeth. Further studies are needed to reveal if individual patterns in the in vitro binding characteristics of saliva lead to variation of colonization in vivo.