冠部牙本质深龋细菌学分析

目的：探明牙本质深龋中的主要相关菌。方法：利用色谱法、裂解法等对龋坏牙本质分三层作细菌分离、鉴定、分析。结果：牙本质龋中的主要相关菌为乳杆菌和变链菌,龋内层牙本质中的细菌含量较外层少。结论：乳杆菌促进牙本质龋的发展,在牙本质龋进展中脱矿在先,细菌入侵在后。     

根周细菌对胶原包被羟磷灰石粘附的体外实验研究

目的：细菌对牙面的粘附能力与其致龋性密切相关，本研究旨在比较对牙面具有粘附能力的变形链球菌ATCC25175、粘性放线菌ATCC15987、乳杆菌ATCC4546、牙龋卟啉菌ATCC33277及中间普氏菌ATCC25611对胶原包被羟磷灰石实验膜（C－HA）的粘附能力，探讨口腔细菌在根周疾病中的作用。方法：采用同位素闪烁计数法测定上述五种细菌对胶原处理的羟基磷灰石（C－HA）的粘附能力，以[^3H]胸腺嘧啶核苷为标记对细菌的粘附进行定量观察，用每分钟的同位素放射量CPM表示（counts per mintue）。结果：所有细菌对C－HA表面的粘附率均有统计学意义（P＜0．01），粘性放线菌对C－HA表面的粘附率显著高于其它细菌组，牙龋卟啉菌及乳杆菌对C－HA表面的粘附率次之，变形链球菌及中间普氏菌对C－HA表面的粘附能力最弱。结论：不同的根周细菌对胶原包被的羟磷灰石的选择性粘附作用不同，粘性放线菌、乳杆菌及牙龋卟啉菌对胶原具较强的亲和作用，在细菌的局部定植过程及疾病的进展中发挥重要作用。     

牙本质深龋细菌学研究进展

深龋为临床常见牙体疾患，为能成功地进行活髓保存治疗，近年来，国外学者对其相关细菌进行分离、鉴定。发现冠部牙本质龋中变链菌和乳杆菌的检出率和占可培养菌百分比均较高；根部牙本质龋中放线菌的检出率和占可培养菌百分比最高，其次为变链菌和乳杆菌。不论冠龋还是根龋乳杆菌与牙本质龋的进展及继发龋的发生和发展均密切相关。这些结果将为无创伤处理深龋、无痛补牙等技术提供细菌学方面的理论依据。     

超氧化物歧化酶对变链菌生长和粘附影响的实验研究

目的：了解超氧化物歧化酶（ＳＯＤ）对变链菌Ｉｎｇｂｒｉｔ、６７１５生长和粘附的影响情况。方法：用麦氏比浊法分别比较不同浓度ＳＯＤ对两种变链菌蔗糖琼脂培养基纯培养的细菌生长量；用液闪计数值比较ＳＯＤ对两种变链菌体外在羟基磷灰石（ＨＡ）上的粘附量。结果：在ＳＯＤ存在时，两种致龋菌的生长量大于没有ＳＯＤ时的生长量；ＳＯＤ作用于获得性膜和致龋菌的体外粘附过程时，两种致龋菌的粘附量显著降低，ＳＯＤ作用于致龋菌生长过程，变链菌Ｉｎｇｂｒｉｔ的粘附量升高，变链菌６７１５的粘附量显著降低。结论：外源性ＳＯＤ促进致龋菌的生长，使致龋菌的粘附量发生改变     

变形链球菌和乳杆菌与龋病发病的关系

<正> 为探索与龋病发病有关的致龋菌,本文作者曾报道在乳磨牙(牙合)面裂沟中变形链球菌(以下简称变链菌)的阳性检出率,在有龋组非常显著地高于无龋组。本文进一步研究变链菌和乳杆菌在乳磨牙无龋、釉质龋裂沟菌斑和牙本质深龋中的出现情况(实验一)以及两菌与裂沟龋发病关系的追踪观察(实验二)。     

奶瓶龋的变链菌和乳杆菌水平及产酸分析

目的:探讨变链菌和乳杆菌与奶瓶龋的关系。方法:将2~215岁幼儿30名分为有龋组和无龋组,每组15 名。从上前牙唇面刮取牙菌斑,进行细菌培养,对变链菌和乳杆菌数目作出统计。取全口牙菌斑,用酶联仪进行乳酸分析。结果:奶瓶龋儿童有较高的变链菌和乳杆菌检出率,两者检出率均为100%。龋损部位的变链菌和乳杆菌数目为5110?1136和4182?1118,超过无龋儿童的相应部位。有龋儿童耐酸菌产乳酸量13629116nmol/OD?161194 nmol/OD高于无龋儿童。结论:变链菌和乳杆菌可能是奶瓶龋的主要病原菌。     

猛性龋儿童变链菌分离株的初始粘附能力

目的 :探讨猛性龋儿童变链菌和远缘链球菌临床分离株的初始粘附能力。方法 :采用唾液包被羟磷灰石 (SHA)及同位素标记方法 ,检测猛性龋、非猛性龋、无龋儿童变链菌 (各 6株 )和远缘链球菌 (猛性龋儿童6株 ,非猛性龋和无龋儿童各 3株 )临床株对SHA的粘附情况。结果 :各组变链菌分离株之间及各组远缘链球菌分离株之间对SHA的粘附率无显著差异 ;在无蔗糖条件下 ,各组远缘链球菌分离株对SHA的粘附百分率均低于各组变链菌 ,差异有显著性 (P <0 .0 5 )。结论 :变链菌的初始粘附能力强于远缘链球菌 ;猛性龋儿童变链菌和远缘链球菌临床株对SHA的初始粘附能力与非猛性龋及无龋儿童无差别。     

高龋及无龋儿童变形链球菌分离株的蔗糖粘附能力比较

目的:探讨高龋和无龋儿童变形链球菌(变链菌)临床分离株的蔗糖依赖性粘附能力。方法:选取本实验室从10例高龋儿童和10例无龋儿童(3￣5岁)牙菌斑内分离、鉴定所得的60株变链菌临床分离株进行研究。采用紫外分光光度计,检测来自高龋儿童(dmfs≥6)的39株和无龋儿童(dmfs=0)的21株变链菌在含糖培养基中对玻壁的粘附情况。采用SPSS12.0软件包进行单因素方差分析,比较高龋儿童和无龋儿童之间牙菌斑内变链菌分离株的玻壁粘附能力。结果:在含1%蔗糖的培养基中,高龋组变链菌分离株对玻壁的粘附比平均值为(55.49+26.16)%,无龋组变形链球菌分离株对玻壁的粘附比平均值为(27.01+18.39)%,2组间差异具有显著性,P<0.01。结论:在含蔗糖环境中,分离自高龋儿童牙菌斑的变链菌株对玻壁的粘附能力高于来自无龋儿童的变链菌分离株,提示变链菌临床分离株的粘附能力与其致龋力相关。     

花多酚、鞣酸抗细菌生长、粘附能力的研究

目的：探讨茶多酚、鞣酸对致龋菌生长、粘附能力的影响。方法：参照已有的多酚、鞣酸溶液MIC,观察不同浓度药液中变边菌Ing、6715和粘放菌ATCC19246的生长、粘附情况。结果：茶多酚对变链菌lng的生长有较强的抑制能力,而鞣酸对三种受试菌的生长均有较强抑制能力,二药对变链菌Ing、6715有轻微的抗粘附活性。,对粘放菌19246则无作用。结论：茶多酚、鞣酸具有一定的抑制细菌生长能力,并变链菌Ing、6715有轻微的抗粘附活性。     

变形链球菌粘附调节基因研究进展

变形链球菌是主要致龋菌之一。粘附是变链菌形成生物膜的初期阶段,也是必经阶段,是公认的细菌四大致龋条件(细菌的粘附、生物膜形成能力、菌细胞代谢碳水化合物能力及细菌对不断波动环境的适应能力)之一。分析与粘附相关的变链菌基因,将有助于我们从分子水平上探索变链菌在生物膜环境中的致龋机理,为从基因水平探索和丰富龋病病因学及龋病防治提供理论依据。     

In vitro evaluation of yoghurt starter lactobacilli and Lactobacillus rhamnosus GG adhesion to saliva-coated surfaces

Aim:  The aim of the study was to evaluate the adhesion of Lactobacillus delbrueckii subsp . bulgaricus and Lactobacillus rhamnosus strain GG to saliva-coated surfaces in vitro .
Methods:  Fifteen radiolabeled dairy L. delbrueckii subsp . bulgaricus strains and L. rhamnosus GG were tested for their ability to adhere to saliva-coated hydroxyapatite beads and polystyrene microtiter plates and the radioactivity was measured by liquid scintillation counter. The effects of lysozyme on the adhesion of lactobacilli and of pretreatment with lactobacilli on the adhesion of Streptococcus sanguinis were also assessed.
Results:  All strains tested adhered to saliva-coated surfaces but with significantly different binding frequencies. The adhesion of the L. delbrueckii subsp . bulgaricus strains remained lower in comparison to L. rhamnosus strain GG. One L. delbrueckii subsp . bulgaricus strain showed binding frequency comparable to S. sanguinis . Lysozyme pretreatment of the samples significantly increased lactobacillus adhesion to saliva-coated surfaces.
Conclusion:  The present results showed significant variations in the adhesion capacity of the Lactobacillus strains studied. Adhesion to oral surfaces is of primary importance for bacterial colonization in the mouth. Only one of the L. delbrueckii subsp . bulgaricus dairy starter culture strains investigated had a high adhesion percentage. This strain might then be considered for further investigations in the oral environment.     

高致龋性变异链球菌临床分离株的初步筛选

目的 初步筛选高致龋性变异链球菌临床分离株。方法 通过检测41株变异链球菌临床分离株的产酸能力、耐酸能力、黏附能力和合成细胞外多糖能力,初步筛选出高致龋性变异链球菌临床分离株。结果 不同的变异链球菌临床分离株体外致龋能力不同,其中3株产酸能力、耐酸能力、黏附能力和合成细胞外多糖能力均较高,提示可能为高致龋性变异链球菌临床分离株,另外3株产酸能力、耐酸能力、黏附能力和合成细胞外多糖能力均较低,提示可能为低致龋性变异链球菌临床分离株。结论 通过筛选可能获得了高致龋性变异链球菌临床分离株。     

Bonding of MMA-TBB resin to bovine tooth coated by poly (methyl methacrylate-co-p-styrene sulfonic acid)

The objective of this study was to prepare a new type water soluble bonding agent, methyl methacrylate (MMA)-p-styrene sulfonic acid copolymer (MS), and to investigate the effect of MS on bonding between resins and tooth substrates. MS is cross-linked with Ca2+ supplied by hydroxyapatite in a smeared layer on ground enamel and dentin and sticks to their surface. Samples were prepared by bonding an acrylic rod with MMA-TBB resin to ground enamel and dentin coated with an aqueous mixture of FeCl3 and 10 wt% MS. After immersed in water for 24 hrs, the tensile bond strength was measured. The bond strengths to both enamel and dentin were higher than 11 MPa and cohesive failure of cured MMA-TBB resin was observed in every case. This suggested that MS could adhere to tooth substrates with a new bonding mechanism different from the previously reported mechanism of the monomer interpenetration and polymerization.     

龋蚀检知液对细菌的影响

目的：了解龋蚀检知液对牙本质细菌的影响。方法：试管稀释法药敏试验及常规牙本质细菌分离鉴定。结果：经χ２检验，染色前后牙本质细菌的几何均数和检出率无显著差异。结论：检知液染色龋坏牙本质对其中的细菌无影响。     

The measurement of growth curve and generation time of lactobacillus]

OBJECTIVE:The purpose of this test was to understand the growth pattern of lactobacillus for the research of its cariogenicity. METHODS: The growth quantity of lactobacillus which was culture in a constant condition was measured periodically by spectrophotometry and flora counting,and its growth curve and generation time were measured. RESULTS: It was found that the logarithmic phase of lactobacillus was 6-16 hours after it was cultured.And its generatin time was 54 minutes. CONCLUSIN: The growth curve of lactobacillus was in accordance with streptococcus mutan.     

氟磷灰石晶体膜对变异链球菌早期粘附和生物膜形成的作用

目的:研究牙本质表面再生氟磷灰石晶体膜(Fluorapatite crystal film,FACF)对变异链球菌(S.mutans)早期粘附和生物膜形成的作用。方法:近生理条件下(37℃,1 atm,pH 6.0~7.4),在牙本质表面沉积FACF,并将牙本质、羟基磷灰石(hydroxyapatite,HA)和氟磷灰石(fluorapatite,FA)样本作为对照组,SEM观察表面形貌。激光共聚焦显微镜(CLSM)和SEM观察牙本质和FACF表面S.mutans的早期粘附情况。HA、FA、牙本质及FACF表面培养S.mutans生物膜,CLSM观察并计算生物膜量。结果:FACF厚5~10μm,晶体呈标准的六棱柱样,排列规则紧密,直径0.5~1.0μm。FACF表面S.mutans粘附量显著少于牙本质(P<0.05),单位面积生物膜量显著低于HA、FA及牙本质(P<0.05),且阻挡了S.mutans向牙本质小管内生长。结论:在近生理条件下,可在牙本质表面再生出厚5~10μm的FA有序致密晶体膜,该层晶体结构可减少S.mutans的初期粘附及生物膜的形成,并对S.mutans向牙本质小管内生长起到物理屏障作用。     

In vitro evaluation of yoghurt starter lactobacilli and Lactobacillus rhamnosus GG adhesion to saliva‐coated surfaces

Aim: The aim of the study was to evaluate the adhesion of Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus rhamnosus strain GG to saliva‐coated surfaces in vitro. Methods: Fifteen radiolabeled dairy L. delbrueckii subsp. bulgaricus strains and L. rhamnosus GG were tested for their ability to adhere to saliva‐coated hydroxyapatite beads and polystyrene microtiter plates and the radioactivity was measured by liquid scintillation counter. The effects of lysozyme on the adhesion of lactobacilli and of pretreatment with lactobacilli on the adhesion of Streptococcus sanguinis were also assessed. Results: All strains tested adhered to saliva‐coated surfaces but with significantly different binding frequencies. The adhesion of the L. delbrueckii subsp. bulgaricus strains remained lower in comparison to L. rhamnosus strain GG. One L. delbrueckii subsp. bulgaricus strain showed binding frequency comparable to S. sanguinis. Lysozyme pretreatment of the samples significantly increased lactobacillus adhesion to saliva‐coated surfaces. Conclusion: The present results showed significant variations in the adhesion capacity of the Lactobacillus strains studied. Adhesion to oral surfaces is of primary importance for bacterial colonization in the mouth. Only one of the L. delbrueckii subsp. bulgaricus dairy starter culture strains investigated had a high adhesion percentage. This strain might then be considered for further investigations in the oral environment.     

Influence of dentin on the effectiveness of antibacterial agents

The influence of dentin on the effectiveness of three antibacterial agents (triclosan, glutaraldehyde, NaOCl) on Streptococcus mutans, S. sobrinus, and Lactobacillus acidophilus was tested using the agar diffusion method with and without bovine dentin discs (200 mum and 500 mum thickness) placed between bacteria and test substances. The effect of 0.3% triclosan on all tester strains (100%) was reduced after passage through 500 mum dentin discs to 0% (L. acidophilus) and to 22% and 28% (S. mutans and S. sobrinus). Seal&Protect (Dentsply, Konstanz, Germany), a triclosan containing dental bonding agent, produced inhibition zones only against S. mutans, but no zone when applied on 200 mum dentin discs. The inhibition zones for 1% NaOCl and 5% glutaraldehyde against all tester strains were significantly increased up to 230% (glutaraldehyde) and 236% (NaOCl) when applied on dentin discs, compared to direct application (100%). Dentin may either decrease or increase the inhibitory effect of antibacterial agents.     

羟基磷灰石柱层析法比较几种细菌粘附力的研究

应用羟磷灰石柱层析法层衍变形链球菌MT6R（c血清型）、远缘链球菌OMZ106（d血清型）、乳杆菌和粘性放线菌（ATCC19246），比较不同细胞对羟磷灰石粘附力的大小，并用唾液包被羟磷灰石柱后观察上述细菌粘附力的改变。结果表明无唾液时细菌粘附力依次为变链菌＞远缘链球菌＞粘性放线菌，乳杆菌最弱。有唾液时，变链菌粘附力明显高于其余三种细菌，粘放菌和乳杆菌与无唾液时比较粘附力亦有增强。远缘链球菌的粘附力无明显改变。