中药大黄对口腔致龋菌影响的体外实验研究

目的：通过研究大黄对致龋菌生工，产酸及产胞外多糖的影响，探讨大黄能否有效调节口腔菌生态平衡。方法：测定大黄变形链球菌，粘性放线菌和血链球菌的最低抑菌浓度MIC。再测定低于MIC的4个浓度的大黄对3种细菌产酸及产生水不溶性多糖能力的影响。结果：大黄对3种细菌的生长，产酸均有一定的抑制作用；并能够有效抑制变形链球菌产生水不溶性葡聚糖。结论：大黄能有效抑制变形链球菌，粘性放线菌和血链球菌的和长，产酸以及抑制变形链球菌产生水不溶性葡聚糖。     

蜂胶与柠檬提取物混合液对变形链球菌作用的体外研究

目的：探讨蜂胶与柠檬提取物混合液对变形链球菌（Streptococcus mutans．S．m）生长、产酸的抑制作用,以及对主要致龋毒力因子乳酸脱氢酶（Lactate dehydrogenase,LDH）活性的影响。方法：分别测定蜂胶、柠檬以及两者混合液的最小抑菌浓度（MIC）值,通过分级抑制浓度（FIC）指数来判断两者联合使用对S．m（ATCC25175）生长作用的影响,并在低于混合液最小抑菌浓度的混合液中培养S．m,用pH计测其培养前后的ApH（酸碱度的变化）,同时采用还原性辅酶I氧化法测定混合液对S．m乳酸脱氢酶活性的影响。结果：蜂胶与柠檬提取物混合液对变形链球菌的体外抗菌活性具有相加作用,随着菌混合液浓度的升高,△pH和乳酸脱氢酶活性逐渐降低。结论：蜂胶与柠檬提取物混合液能有效的抑制变形链球菌的生长,对其产酸及乳酸脱氢酶有较强的抑制作用。     

鞣花酸对变异链球菌的体外抑菌作用及机制研究

目的:研究鞣花酸对变异链球菌的体外抑菌作用及可能机制,为其防治龋病的应用提供实验依据。方法:以复方氯己定含漱液为阳性对照、5%二甲基亚砜(DMSO)溶液为阴性对照,采用打孔法抑菌试验测定抑菌圈直径考察50、25、12.5、6.25、3.125、1.562 5 mg/mL鞣花酸对变异链球菌的抑菌效果,并采用微量稀释法测定其对变异链球菌的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。以5%DMSO溶液为阴性对照,采用结晶紫染色法测定1/8MIC、1/4MIC、1/2MIC、MIC鞣花酸对变异链球菌生物膜形成的影响,并在荧光染色后通过激光扫描共聚焦显微镜观察1/2MIC鞣花酸作用后生物膜的结构变化;分别采用苯酚硫酸法和还原型辅酶Ⅰ氧化法考察1/8MIC、1/4MIC、1/2MIC、MIC鞣花酸对变异链球菌细胞外多糖(EPS)的抑制率和细胞外基质中乳酸脱氢酶(LDH)活力的影响。结果:12.5～50 mg/mL鞣花酸对变异链球菌产生了直径均大于15 mm的抑菌圈,50 mg/mL鞣花酸作用下抑菌圈直径与复方氯己定含漱液相当。鞣花酸对变异链球菌的MIC、MBC分别为12.5、25 mg/mL。1/8MIC～MIC鞣花酸作用后细菌生物膜的存活率较阴性对照显著降低(P<0.01),且呈剂量依赖趋势,MIC鞣花酸作用后细菌生物膜的存活率仅为(16.41±1.346)%;荧光染色后显微镜下可见,1/2MIC鞣花酸作用后细菌生物膜结构被破坏;1/8MIC～MIC鞣花酸作用后细菌水不溶性EPS和水溶性EPS的抑制率较阴性对照均显著升高(P<0.01),1/4MIC～MIC鞣花酸作用后细胞外基质中LDH活力较阴性对照均显著升高(P<0.01),且呈剂量依赖趋势。结论:鞣花酸对变异链球菌的生长具有一定的抑制作用;其机制可能与抑制EPS产生、降低细菌的黏附、破坏细菌细胞膜有关。     

龋齿预防接种

龋齿在发达国家中是一种十分常见的疾病.近几年来,也许是由于氟化物的使用,使龋齿发病明显减少,但仍是青少年最常见的慢性病之一.本文介绍了龋齿的预防接种,并着重论述用于防龋的抗原及其免疫机理.致龋菌龋齿发生条件:(1)致龋菌:能迅速产酸,使pH<5.5以溶解牙釉质;(2)糖:食物中的糖有利于细菌定居,并可被后者代谢而产酸.一些细菌能使无菌大鼠发生龋齿.在致龋链球博、乳杆菌和放线菌中,似以变形链球菌(以下简称变链菌)的致龋力最强,并与人龋齿有关.近年来龋齿免疫研究大多是用变链菌接种龋齿动物、猴和人进行的.     

葡萄糖酸氯己定漱口水在人工模拟口腔环境中抑制菌斑的实验

目的：研究葡萄糖酸氯己定抑制致龋菌生长和抗牙菌斑形成作用。方法：应用模拟人类口腔环境和几种致龋菌混合人工牙菌斑模型,对葡萄糖酸氯已定漱口水抑制致龋菌和抗牙菌斑形成进行了扫描电镜观察和细菌同位素标记计数检测。结果：同位素计数显示使用葡萄糖酸氯已定漱口水细菌数明显减少,扫描电镜观察证明葡萄糖酸氯己定漱口水可防止细菌聚积形成牙菌斑。结论：葡萄糖酸氯已定漱口水在抑制致龋菌生长,抗菌斑形成方面具有显著作用。     

第三讲 社区常见疾病 第八章11腔常见疾病

第一节龋病 龋病是牙体硬组织在以细菌为主的多因素影响下，发生脱钙崩解、造成牙齿缺损、破坏的一种慢性进行性疾病。龋病是人类多发病、常见病之一，主要的致龋菌是变形链球菌，其次是乳酸杆菌和放线菌。牙体组织一旦形成龋洞，因缺乏自身修复能力，不可能自行恢复。     

毛冬青中有效成分的分离及其对两种主要口腔致病菌的抑制作用

目的 观察、追踪毛冬青抑制口腔常见致龋菌（变形链球菌和具核梭杆菌）的有效部位和成分。方法 通过系统溶剂萃取、大孔树脂及硅胶柱色谱分离等方法以及质谱和核磁共振等鉴定技术,结合液体二倍稀释法,研究毛冬青不同部位及单体对变形链球菌和具核梭杆菌的最低抑菌浓度（MIC）,1%玉洁纯作为阳性对照药。结果 毛冬青三萜总皂苷和冬青素对两种主要口腔致病菌均具有一定的抑制作用,特别对变形链球菌具有显著地抑制效果。结论 毛冬青三萜总皂苷和冬青素对变形链球菌具有很强的抑制作用,具有开发成为抗龋齿的保健牙膏或药品的潜力。     

抗龋健齿含片的研制

目的　研制一种具有较强防龋健齿作用 ,无毒副作用和使用方便的口含片。方法　以经反复实验筛选出的具有较强杀灭或抑制人类主要致龋菌———变形链球菌作用的植物药物金银花提取物 (有效成分氯原酸 )和甘草提取物 (有效成分甘草酸铵 )为主药 ,配伍钙、锌等矿物质和微量元素 ,经一定的加工工艺制成口含片缓释药物剂型并经体内外实验 ,观察该药抑菌、抑酸和对离体牙的防龋效果 ,经在体临床观察药物抑制菌斑形成的作用和在口腔内的浓度及维持的时间。结果　药物对变形链球菌的生长、产酸及菌斑的形成有较强的抑制作用 ;能增强离体牙的抗龋能力 ,减少龋病的发生率 ;在口腔内能维持较高的药物浓度和较长的时间。结论　抗龋健齿含片是一种有较强防龋健齿作用 ,使用方便 ,无毒副作用的抗龋药物     

研究薄荷复方煎液对龋病、牙周病致病菌的抑制和杀灭作用

目的:观察并分析薄荷复方煎液在抑制龋病和牙周病的各种致病菌中的作用.方法:本研究中的实验菌株主要包括牙龈卟啉单胞菌和血链球菌,所用药方为薄荷复方煎液,重点观察它在抑制龋病和牙周病的各种致病菌中的作用.结果:薄荷复方煎液能够有效地减少牙龈卟啉单胞菌及血链球菌的产酸量,能够抑制其生物活性,从而减少不溶性葡聚糖的合成.结论:对于口腔细菌的糖代谢以及酸代谢来说,薄荷复方煎液均能发挥抑制效果.     

LuxS基因突变对变形链球菌生长的初步研究

目的研究luxS基因突变对变形链球菌生长的影响。方法采用比浊法测定不同培养条件下变形链球菌luxS基因缺陷株培养液的吸光度A值。结果基因缺陷株细菌A值明显低于变链菌标准株,差异有统计学意义(P<0.001);对培养基的初始pH值递减敏感性增加。结论LuxS基因突变可以抑制变形链球菌的生长,基因缺陷株的耐酸性降低。     

Antimicrobial activity of N-alkylethylenediamines against oral and other microorganisms

Six N-alkylethylenediamines were synthesized and antimicrobial activity of each compound against oral microorganisms such as Streptococcus mutans, Actinomyces viscosus and Actinomyces naeslundii, and some others were determined in vitro. Dodecyl or tetradecyl derivative possessed maximum bacteriostatic activity among the test compounds. On the other hand, killing time of S. mutans in aqueous solution decreased with increasing alkyl-chain length.     

Antibacterial diterpenoids from Sagittaria pygmaea

There were five new diterpenoids, 18-beta-D-3',4'-diacetoxyxylopyranosyl-ent-kaur-16-ene (1), 18-beta-L-3',5'-diacetoxyarabinofuranosyl-ent-kaur-16-ene (2), 18-beta-D-3',6'-diacetoxyglucopyranosyl-ent-kaur-16-ene (3), ent-isopimar-8(14),15-dien-19-oic acid (4), and 5alpha-hydroxy-ent-rosa-15-en-18-oic acid (5), isolated from the whole herb of Sagittaria pygmaea. Their structures and relative configurations were established based on spectroscopic studies, chemical methods, and X-ray crystallographic analysis. Compound 2 exhibited significant antibacterial activity against the oral pathogens, Streptococcus mutans ATCC 25 175 and Actinomyces viscosus ATCC 27 044, with MIC values against both pathogens of 15.6 microg/mL. Compound 3 was active against only A. viscosus ATCC 27 044 with an MIC value of 62.5 microg/mL. Compounds 4 and 5 were active against S. mutans ATCC 25 175 and A. viscosus ATCC 27 044, with MIC values against both pathogens of 125.0 microg/mL.     

Antimicrobial activity of tanzanian chewing sticks against oral pathogenic microbes

Methanol extracts from the bark and wood of ten plants used as chewing sticks in Morogoro region, in Tanzania, were tested for their ability to inhibit the growth of cariogenic bacteria, Streptococcus mutans , Actinomyces viscosus and a yeast Candida albicans . Screening for antimicrobial activity was done by the agar-hole diffusion method, and minimum inhibitory concentrations (MICs) were determined by the agar dilution method. Extracts from seven out of the ten plants showed varying degrees of growth inhibitory effect on the microorganisms, with Acacia senegal var. senegal stem bark being the most active, followed by the stem bark of Eriosema psoraleoides . Their MICs ranged from 0.63 mg/ml to 5 mg/ml. Three plants Ocimum suave , Opilia celtidifolia and Xerophyta suaveolens did not exhibit any antimicrobial effect. Actinomyces viscosus was relatively more sensitive to the extracts than S. mutans and C. albicans . This study has also demonstrated that most bark extracts possessed antimicrobial activity, while many wood extracts were inactive. It is, therefore, advisable to use, for toothbrushing, unpeeled, rather than peeled chewing sticks, in order to exploit fully their antimicrobial effect. However, additional studies are needed to determine their antiplaque, anticaries and antimycotic effects.     

Antimicrobial Activity of Tanzanian Chewing Sticks Against Oral Pathogenic Microbes

Methanol extracts from the bark and wood of ten plants used as chewing sticks in Morogoro region, in Tanzania, were tested for their ability to inhibit the growth of cariogenic bacteria, Streptococcus mutans , Actinomyces viscosus and a yeast Candida albicans . Screening for antimicrobial activity was done by the agar-hole diffusion method, and minimum inhibitory concentrations (MICs) were determined by the agar dilution method. Extracts from seven out of the ten plants showed varying degrees of growth inhibitory effect on the microorganisms, with Acacia senegal var. senegal stem bark being the most active, followed by the stem bark of Eriosema psoraleoides . Their MICs ranged from 0.63 mg/ml to 5 mg/ml. Three plants Ocimum suave , Opilia celtidifolia and Xerophyta suaveolens did not exhibit any antimicrobial effect. Actinomyces viscosus was relatively more sensitive to the extracts than S. mutans and C. albicans . This study has also demonstrated that most bark extracts possessed antimicrobial activity, while many wood extracts were inactive. It is, therefore, advisable to use, for toothbrushing, unpeeled, rather than peeled chewing sticks, in order to exploit fully their antimicrobial effect. However, additional studies are needed to determine their antiplaque, anticaries and antimycotic effects.     

Antimicrobial and anti-plaque activity of N'-alkyl-N-(2-aminoethyl)piperidine against dental plaque bacteria

Five N'-alkyl-N-(2-aminoethyl)piperidines were synthesized and their in vitro antimicrobial activities were tested against four micro-organisms related to dental caries (Streptococcus mutans, S. sobrinus, Actinomyces viscosus, and A. naeslundii) which are known to be implicated in dental caries. The tetradecyl and hexadecyl derivatives possessed good bacteriostatic activity. Some derivatives exhibited a rapid bactericidal effect against S. mutans and S. sobrinus in aqueous solution. These compounds also possessed surfactant properties and anti-plaque activity.     

5-(Alkylsulfonyl)salicylanilides as potential dental antiplaque agents

A series of 22 5-(alkylsulfonyl)salicylanilides was synthesized and evaluated for in vitro antibacterial and antiplaque activity against Actinomyces viscosus and Streptococcus mutans, adherent microorganisms implicated in periodontal disease and dental caries. The minimum inhibitory concentrations of 25 salicylanilides (including 5-acyl-, 5-alkyl-, and 5-(alkylsulfonyl)-4'-bromo- and -4'-(trifluoromethyl)salicylanilides) were found to correlate (r = 0.94) with estimated log D values. Several salicylanilides, such as 5-(decylsulfonyl)- and 5-(dodecylsulfonyl)-4'-(trifluoromethyl)salicylanilides (15 and 19) were found to exhibit high levels of in vitro antibacterial and antiplaque activity against A. viscosus and S. mutans.     

氮离子溅射对钛合金表面细菌黏附的影响

目的研究氮离子溅射对钛合金表面细菌黏附能力的影响。方法制作钛合金试件144件,随机选出72件,采氮离子溅射法对其表面改性,钛合金组为对照组,氮离子溅射组为实验组。在实验组和对照组试件表面粘附血型链球菌、黏性放线菌、白色念珠菌,分别进行细菌体外黏附实验。用菌落形成单位计数法统计分析氮离子溅射前后各种细菌黏附量的变化。结果在细菌黏附24、48、168h,上述3种细菌在实验组表面黏附量较对照组表面黏附量显著减少(P<0.001)。结论氮离子溅射可抑制钛合金表面细菌黏附。     

钛合金表面改性对细菌黏附的影响

目的研究钛合金表面改性形成氨化钛膜对细菌黏附能力的影响.方法制作钛合金试件144件,随机选出72件,采用多弧离子镀法在其表面改性形成氨化钛膜,钛合金为对照组,镀膜后钛合金为实验组.在实验组和对照组试件表面黏附血链球菌、黏性放线菌、白色念珠菌,分别进行细菌体外黏附实验.用菌落形成单位计数法统计分析氨化钛膜形成前后各种细菌黏附量的变化.结果在细菌黏附24、48、168h,上述3种细菌在实验组表面黏附量较对照组表面黏附量显著减少(P<0.001).结论钛合金表面改性形成氨化钛膜可抑制细菌黏附.     

五倍子的体外抑菌作用研究

目的探讨五倍子的体外抑菌作用。方法用K—B纸片扩散法。100％五倍子浸出液滤纸片对金黄色葡萄球菌、白色葡萄球菌、大肠杆菌、伤寒杆菌、铜绿假单胞菌、变形杆菌、甲型链球菌、乙型链球菌抑菌作用进行了研究。结果五倍子对以上细菌均有明显的抑菌作用。结论五倍子在体外有明显抑菌作用。