金银花甘草人工唾液防龋的实验研究

目的 探讨金银花甘草人工唾液对龋病发生发展的抑制效果.方法 乙醇提取金银花和甘草有效成分并加入到人工唾液中,采用液体稀释法检测其抑制变形链球菌和远缘链球菌的效果;诱导摘除腮腺后的SD大鼠致龋,建立人工龋大鼠模型,分别用金银花甘草人工唾液、甲硝唑洗必泰溶液、人工唾液和蒸馏水给4组大鼠施药,采用Keyes记分法观察金银花甘草人工唾液对大鼠口腔内龋齿发生发展的抑制效果.结果 其对变形链球菌ATCC10449株和远缘链球菌OMZ65株的最小抑菌浓度分别为25、12.5 mg/ml,最小杀菌浓度分别为200、100 mg/ml.在人工龋大鼠模型中,与蒸馏水及人工唾液组相比,金银花甘草人工唾液龋齿计分明显降低,但仍高于甲硝唑洗必泰组.结论 金银花甘草人工唾液对变形链球菌和远缘链球菌生长有明显抑制作用,并可有效抑制大鼠口腔内龋齿的发生发展.     

复方苦参漱口液对口腔常见致病菌的抑制作用

目的:研究复方苦参漱口液对口腔常见致病菌的体外抑制作用。方法:对嗜酸乳杆菌等6种口腔常见致病菌的标准菌株采用培养基体外培养增殖,测定苦参漱口液的最低抑菌浓度、MIC50、MIC90;平板法测定抑菌强度,并与茶多酚作比较。结果:复方苦参漱口液对6种标准菌株的最低抑菌浓度均低于原液浓度。对致龋菌,复方苦参漱口液取得与茶多酚相似的抑菌效果;对黏膜致病菌,复方苦参漱口液的抑菌作用强于茶多酚。平板抑菌环结果:复方苦参漱口液和茶多酚之间比较无显著差异。结论:复方苦参漱口液有良好的抑菌作用。     

人工合成抗菌肽对口腔细菌抗菌性能的初步研究

目的 评价人工合成抗菌肽（十肽）对口腔常见感染性疾病主要致病菌的抑菌活性。方法 采用琼脂扩散法及液体稀释法体外评价十肽对变异链球菌、表兄链球菌、嗜酸乳杆菌、血链球菌、格氏链球菌、黏性放线菌、内氏放线菌、牙龈卟啉单胞菌、中间普雷沃菌、具核梭杆菌、伴放线嗜血杆菌及白色假丝酵母菌的抑菌性能,并测定十肽对变异链球菌的时间-杀菌曲线。结果 十肽对所选实验菌株均表现出不同的抑菌性能,对主要致龋菌的最小抑菌浓度MIC值为62.5~125 μg·mL^-1,而对主要牙周致病菌的MIC值为250~1 000 μg·mL^-1,其中,十肽对龋病主要致病菌变异链球菌有较强抑菌作用。时间-杀菌曲线结果显示,十肽作用20 min后开始杀菌,30 min之后可完全杀灭细菌,且在24 h之内无细菌生长。结论 新型人工合成抗菌肽十肽对口腔常见感染性疾病主要致病菌具有抑菌性能,其中对致龋变异链球菌的抑菌效果最为明显。     

含C型变形链球菌表面蛋白P_1抗体的唾液膜对两种变形链球菌粘附的影响

用提纯的S．mutansMT6R（遗传Ⅰ型，血清c型）细胞表面蛋白P1加弗氏佐剂通过局部唾液腺和背部皮下注射免疫BALB／C鼠，得到含高效价民抗体的大鼠唾液。用含P1抗体的唾液包被羟磷灰石激珠（HA），观察含在唾液膜中的c型变链P1抗体对S．mutansMT6R和S．sobrinus6715在HA表面粘附的影响。结果发现唾液膜中的P1抗体可明显抑制S．mutansMT6R和S.so－brinus6715在HA表面的粘附（P＜0．05），且抗体对这两种菌的粘附抑制作用无统计学差异（P＞0．05）。提示P1抗体可以抑制S．mutans和S．sobrinus对牙面的粘附和定居．     

橙皮苷防龋作用的动物实验研究

目的：研究橙皮苷在大鼠体内的防龋作用。方法：纸片扩散法检测橙皮苷对远缘链球菌（S．sobrinus）的最小抑菌浓度（MIC）,接种S．sobrinus建立大鼠龋病模型,分别用1／2 MIC橙皮苷、0．12％洗必泰、无菌蒸馏水处理大鼠口腔,菌落计数法动态监测S．sobrinus水平、Keyes龋齿评分法、激光龋齿诊断仪（DIAGNOdent）探测荧光值评价不同处理方法对大鼠龋病发生的影响。结果：橙皮苷的MIC为8 mg／ml;S．sobrinus水平：橙皮苷组与蒸馏水组相比差异无统计学意义（P＞0．05）;Keyes记分：橙皮苷组光滑面及窝沟E级龋损记分低于蒸馏水组（P＜0．05）,橙皮苷组窝沟Ds级、Dm级龋损记分低于蒸馏水组（P＜0．05）,高于洗必泰组（P＜0．05）;DIAGNOdent探测荧光值：橙皮苷组龋损程度低于蒸馏水组（P＜0．05）,高于洗必泰组（P＞0．05）。结论：1／2 MIC橙皮苷在不影响大鼠口内菌群水平的前提下,可减少大鼠磨牙龋病形成及减轻龋损程度。     

表兄链球菌的检测与儿童猛性龋的关系

目的：探讨表兄链球菌(Streptococcus sobrinus,S. sobrinus)与儿童猛性龋的关系。方法：根据前期郑州市区猛性龋调查结果,随机抽样选择3～5岁儿童66例,其中猛性龋、普通高龋及无龋组各22例。采用TYCSB培养基作变形链球菌(Streptococcus mutans, S. mutans )及S. sobrinus初步筛选,结合生理生化鉴定,并采用聚合酶链反应作最终鉴定。采用 SPSS10.0软件包对实验组与对照组S.mutans和S.sobrinus的检出率进行χ²检验,组间均数作t检验。结果： S. sobrinus在各组儿童牙菌斑中均不能脱离S. mutans而单独检出,猛性龋组S. mutans检出率高于高龋组,差异无显著性(P>0.05),而2组儿童S. sobrinus检出率的差异有显著性(P<0.05);猛性龋组与无龋组S. mutans检出率差异显著(P<0.05),S. sobrinus检出率差异显著(P< 0.01)。同时检出S. mutans和S. sobrinus的样本,其猛性龋的发生率及龋失补牙数、龋失补牙面数和平滑面龋均数与只能检出S. mutans及2种细菌均不能检出的样本的差异有显著性(P< 0.01)。结论：S. mutans与S. sobrinus是儿童猛性龋的主要致病菌,S. sobrinus与儿童猛性龋的发生有关。S. sobrinus对儿童猛性龋的发生、发展具有协同作用。     

薄荷复方煎液对龋病、牙周病致病菌杀菌作用的研究

目的：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。方法：致龋菌血链球菌、变形链球菌和牙周病致病菌牙龈卟啉单胞菌分离培养,将薄荷复方煎液配成不同浓度,分别对4种细菌做药敏试验,记录各自的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。结果：血链球菌MIC1：32,变形链球菌MIC1：4,牙龈卟啉单胞菌MIC1：32;血链球菌MBC1：16,变形链球菌MBC1：1,牙龈卟啉单胞菌MBC1：8。结论：薄荷复方煎液对龋病、牙周病致病菌有抑制和杀灭作用。     

几种制剂对口腔主要致龋菌抑制作用的比较

目的 :研究玉洁纯、硫酸锌、茶多酚以及它们相对配伍的制剂应用于龋病预防的可能性。方法 :采用液体稀释法体外抑菌实验比较玉洁纯、硫酸锌、茶多酚以及它们配伍使用时对口腔主要致龋菌S .mutansIngbritt、S .sobrinus　 6 715的抑制效果。结果 :以上三种制剂均能有效地抑制主要致龋菌的生长 ,其中玉洁纯的抑菌效果最为显著 ;硫酸锌和茶多酚都不能有效地促进玉洁纯的抑菌作用。结论 :玉洁纯作为一种高效低毒的抑菌剂可以考虑用于龋病预防 ,硫酸锌对玉洁纯抑菌效果的影响有待进一步研究。     

Effect of Magnolia Officinalis Extract on Cariogenic Activity of Mutans Streptococci

目的：从中药厚朴中提取抗变链活性成分,并研究其对变形链球菌致龋特性的影响。方法：本研究应用薄层层析,萃取分离,硅胶色谱柱层析等现代中药化学实验方法,从生药厚朴中提取出有效成分MO2,用微量液体稀释法检测不同血清型变形链球菌对MO2的敏感性。以S.mutans MT703和S.sobrinus B13为实验菌株,分析MO2对其细胞表面疏水能力和合成水不溶性葡聚糖能力的影响。结果：MO2能降低细胞表面疏水率,抑制葡糖基转移酶催化合成水不溶性葡聚糖。随着MO2浓度的升高,细胞表面疏水率下降;80μg/ml的MO2对S.mutansMT703合成水不溶性葡聚糖的抑制率为45.4%,对S.sobrinusB13合成水不溶性葡聚糖的抑制率达43.5%。结论：厚朴提取物MO2对变形链球菌致龋能力有较强抑制作用。     

西帕依固龈液和没食子体外抗白色念珠菌的活性测定

目的：体外观察西帕依固龈液和没食子对白色念珠菌的作用,并对二者的抑菌和杀菌效果进行评价。方法：采用常量肉汤稀释法,检测西帕依固龈液和没食子的抑菌和杀菌效果。结果：西帕依固龈液对白色念珠菌的最低抑菌浓度（MIC）为5mg/ml,最低杀菌浓度（MBC）为10mg/ml;没食子提取液对白色念珠菌的最低抑菌浓度（MIC）为25mg/ml,杀菌浓度（MBC）为50mg/ml。结论：没食子提取液和西帕依固龈液在体外均具有一定的抗白色念珠菌活性。     

A re-evaluation of the distribution of the elastic meshwork within the periodontal ligament of the mouse

The elastic properties of the periodontal ligament have been attributed, in part, to oxytalan fibers, as no other types of elastic fibers are described there. It has been difficult to study the periodontal elastic meshwork by standard microscopic techniques because it is partially obscured by the adjacent periodontal ligament collagen fibers. Our study employed methods which either completely or partially removed mandibular molar periodontal ligament collagen fibers, exposing a previously undescribed periodontal elastic meshwork. The periodontal elastic meshwork was composed of many elastin lamellae containing both peripheral microfibrils of regular arrangement and central microfibrils of irregular arrangement, which could only be demonstrated in oxidized tissues. Peripheral, regularly arranged bundles of microfibrils resembled oxytalan fibers, which were often adherent to the border of the elastin lamella. Elastin lamellae containing irregular microfibrils resembled elaunin fibers. These fibers probably enclosed either blood vessels, nerves or collagen fiber bundles. Peripheral microfibrils attached elaunin to cementum, alveolar bone, blood vessels, and principal periodontal collagen fibers. Thus, the periodontal elastic meshwork is composed of both oxytalan and elaunin fibers. Microfibrils attach elaunin fibers to the adjacent non-elastic tissue and also form bundles which traverse the periodontal ligament space and are probably the oxytalan fibers demonstrable by light microscopic techniques. This meshwork of oxytalan and elaunin fibers probably contributes to tooth support and maintenance of periodontal homeostasis by dissipating chewing forces and maintaining patency of periodontal blood vessels.     

秦始皇帝陵区出土人第三磨牙的萌出情况

目的：调查秦始皇帝陵区山任陶窑遗址中人体颌骨第三磨牙的萌出情况。方法：选用秦代人体颌骨98副，观察萌出特点，计算阻生率，分析阻生情况。结果：通过对98副标本的观察，发现秦代人同现代人类一样可发生第三磨牙的多种萌出状况，其中包括先天缺失、畸形牙、阻生、正常萌出等。结论：秦始皇帝陵区山任陶窑遗址中人体颌骨具有同现代人类一样的第三磨牙萌出特点。     

螺圈对垂直曲力学行为的影响

目的 研究不同位置的螺圈及预成角度对垂直曲力学行为的影响。方法 利用大型有限元软件 ANSYS进行模拟计算。结果 螺圈的加入对垂直曲的M/F值的变化较明显。结论 对预成螺圈曲进行合理的形状设计,可以达到满意的效果。     

The variability of the curvature of the labial surface of the upper anterior teeth along the facial axis of the clinical crown

OBJECTIVE: To mathematically assess the curvature of upper anterior teeth along the facial axis of the clinical crown (FACC) line to provide information valuable for assessment of enamel growth. METHODS: Forty upper study models were chosen from the Orthodontic clinic at the Charles Clifford Dental Hospital, Sheffield, UK. The study model incisors and canines were sectioned longitudinally down the FACC line, using a Microslice II cutting machine. Images were captured that showed the proximal view of the tooth curvature from incisal edge/cusp tip to the gingival margin. The images were converted into silhouettes and saved as bitmap files. These were vectorised and converted to an outline of xy data points. The forty xy files were mathematically adjusted so the distance between incisal edge and gingival margin were of equal length. Non Rotational Principal Component Analysis (PCA) was then applied at 20 equal intervals along the curve of each xy file to describe the shape of the teeth. RESULTS: Intra class correlation coefficient for intra-operator repeatability ranged from 0.821-0.998 showing good or excellent levels of reliability. PCA showed variation between tooth types. CONCLUSIONS: The method proved reliable. All tooth types showed that the mid-point region had the greatest rise variable, indicating that the most-prominent point was central or incisal for central and lateral incisors. All were skewed towards the incisal end and had kurtosis at both ends. Central incisors showed least variability. Greater variability was seen within the incisal third than within the gingival third for all tooth types.