唾液乳酸杆菌w22a和种植体周围炎致病菌体外作用的初步研究

目的:研究唾液乳酸杆菌w22a的潜在益生性和与种植体周围炎致病菌:牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)、中间普氏菌(Pevotellaintermedia,Pi)、具核梭酸杆菌(Fusobacteriumncleatum,Fn)的体外作用,为乳酸杆菌w22a作为益生菌应用于种植体周围炎的防治提供实验依据。方法::通过检测w22a代谢产物成分、w22a对抑菌物质的耐受性等,初步探讨其口腔益生特性;并通过自聚和共聚实验、抑菌实验研究唾液乳酸杆菌w22a和种植体周围炎致病菌Pg、Pi、Fn的体外作用。结果:发现唾液乳酸杆菌w22a可产生有机酸、过氧化氢等抑菌物质,并能产生胞外多糖;w22a能够耐受一定浓度的抗生素和溶菌酶;w22a在体外有自聚集和与Pg、Pi、Fn发生共聚集的能力;其代谢产物对于Pg、Pi、Fn的生长具有不同程度的抑制作用。结论:唾液乳酸杆菌w22a能够对Pg、Pi、Fn产生生长抑制作用,具有口腔益生性,有望作为益生菌用于种植体周围炎的防治。     

不同种类无机抗菌剂对口腔致病菌抗菌性能比较及其检测方法探讨

目的:比较无机抗菌剂对口腔致病菌的抗菌活性,并探讨不溶物质的优选测试方法。方法:采用试管液体稀释法和琼脂稀释法测试6种无机抗菌剂对6种口腔常见致病菌的抗菌活性。结果:试管液体稀释法测试结果显著低于琼脂稀释法。受试抗菌剂体外综合抗菌活性从高到低依次为:龙贝无机抗菌粉体、ZnOw AT-83、IONPURE-H、碱式次氯酸镁、ZnOw AT-88、安迪美-AMS2。结论:6种无机抗菌剂对实验菌株均有不同程度的抗菌活性。不溶性物质抗菌活性测试宜用液体稀释法。     

Bactericidal Action of Bicarbonate Ion on Selected Periodontal Pathogenic Microorganisms

Organisms representative of soil, skin and fecal flora and of supragingival and subgingival flora were tested for inhibition of growth and killing by various salts (NaHCO₃, NaCl, MgSO₄). The antimicrobial activities of KHCO₃, NaF, sodium lauryl sulfate (SLS) and chloramine T were also compared with that of NaHCO₃, and the rate at which NaHCO₃ exerts its bactericidal effect was studied. Suspected periodontal pathogens were more susceptible to salts than were control non-oral bacteria. Supragingival plaque organisms showed intermediate susceptibility. Periodontal pathogens were more susceptible to NaHCO₃ than to NaCl; NaHCO₃ and KHCO₃ showed similar activity against all strains tested. Accordingly, the antibacterial activity of NaHCO₃ is not simply an osmotic effect and is due to the bicarbonate ion. NaF, SLS and chloramine T had greater antimicrobial activity than NaHCO₃. Supragingival bacteria required at least 6-hour exposure to 1.0 m NaHCO₃ to produce 99% lethality (decrease colony-forming units by 2 log₁₀), whereas selected periodontal pathogens were killed more rapidly (30–120 minutes). The higher the concentration of bicarbonate, the faster the lethality. Morphologic examination by transmission electron microscopy of organisms exposed to bactericidal salt concentrations revealed marked fibrillar condensations within the cytoplasm and shrinkage of the cytoplasm from the outer membrane. For NaHCO₃ to be clinically effective, a high concentration must be introduced into the periodontal pocket and maintained there long enough to kill periodontal pathogens. Furthermore, NaHCO₃ must be reapplied often enough to prevent recolonization by these pathogens. An advantage of NaHCO₃ over NaF, SLS and other antimicrobial agents is its safety, availability and low cost.     

有抗菌能力的牙周引导组织再生膜的制备研究

目的:在聚乳酸-乙醇酸共聚物[poly(lactic-co-glycolic acid),PLGA]表面接枝2-甲基丙烯酰氧乙基磷酸胆碱(2-methacryloyloxyethyl phosphorylcholine,2-MPC),制备一种具有抗菌能力的牙周引导组织再生膜。方法:用紫外光接枝聚合法将2-MPC接枝于PLGA表面,采用傅立叶变换红外光谱验证接枝的成功,并用扫描电镜观察样品改性前后的表面形貌。以大肠杆菌以及金黄色葡萄球菌为实验菌株,在已接枝的和未接枝的样品表面接种1×106 CFU/mL浓度的细菌悬液,37℃孵育4 h,梯度脱水后扫描电镜观察。并且在材料表面接种小鼠成骨细胞系MC3T3-E1培养12 h,进行活细胞染色观察样品表面细胞形态。结果:红外和扫描电镜结果证明2-MPC成功接枝于PLGA膜表面,抗菌实验结果显示接枝后的材料抗大肠杆菌以及金黄色葡萄球菌粘附能力显著提高,并且体外细胞实验结果证明,表面接枝2-MPC在有效提高材料抗菌能力的同时,2-MPC对材料的生物相容性并没有明显的抑制作用。结论:在PLGA表面接枝2-MPC可以获得一种具有优良抗菌性能的牙周组织引导再生膜材料。     

Antibacterial Activity of Curcumin Against Periodontopathic Bacteria

Background: Curcumin is a polyphenol extracted from root of turmeric and known to possess multifunctional properties, including antibacterial activity. Although previous studies have investigated the effects of curcumin on microorganisms, available knowledge on the effects of curcumin on periodontopathic bacteria is still limited. In this study, the antibacterial effect of curcumin on periodontopathic bacteria is investigated, particularly Porphyromonas gingivalis. Methods: Representative periodontopathic bacteria were cultured in media with and without various curcumin concentrations, and the optical density at 600 nm was measured for 60 hours. The inhibitory effect of curcumin on P. gingivalis Arg‐ and Lys‐specific proteinase (RGP and KGP, respectively) activities were assessed using spectrofluorophotometric assay. Analysis of biofilm formation by P. gingivalis with or without Streptococcus gordonii was conducted using confocal laser‐scanning microscopy (CLSM). Results: Curcumin inhibited the growth of P. gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Treponema denticola in a dose‐dependent manner. Bacterial growth was suppressed almost completely at very low concentrations of curcumin. Conversely, 100 μg/mL curcumin did not suppress the growth of Aggregatibacter actinomycetemcomitans. It also demonstrated inhibitory effects against RGP and KGP activities in a dose‐dependent manner. CLSM revealed that curcumin suppressed P. gingivalis homotypic and P. gingivalis–S. gordonii heterotypic biofilm formation in a dose‐dependent manner. A concentration of 20 μg/mL curcumin inhibited these P. gingivalis biofilm formations by >80%. Conclusion: Curcumin possesses antibacterial activity against periodontopathic bacteria and may be a potent agent for preventing periodontal diseases.     

Antibacterial Activity of Endodontic Sealers against Planktonic Bacteria and Bacteria in Biofilms

Introduction

The aim of this study was to investigate the antibacterial activity of 4 endodontic sealers against bacteria planktonic grown or in biofilms commonly detected from persistent and secondary endodontic infections.

Impact of Oral Commensal Bacteria on Degradation of Periodontal Connective Tissue in Mice

Background: Innate and adaptive immunosurveillance mechanisms in response to the normal commensal bacteria can affect periodontal innate defense status. However, it is still unclear how commensal bacteria contribute to the inflammatory responses of junctional epithelium (JE) and periodontal connective tissue (PCT). The aim of the present study is to investigate the contribution of commensal bacteria on inflammatory responses in JE and PCT in mice. Methods: The periodontal tissue of germ‐free (GF) and specific‐pathogen‐free (SPF) mice were compared at age 11 to 12 weeks (n = 6 per group). In this study, the number of neutrophils and expression of intercellular adhesion molecule (ICAM)‐1, fibroblast growth factor receptor (FGFR)‐1, matrix metalloproteinase (MMP)‐1, and MMP‐8 within the JE and the PCT are evaluated. The collagen density was also determined in PCT stained with picrosirius red (PSR). PSR staining combined with or without polarized light microscopy has been used to assess the organization and maturation of collagen matrix. Results: In the present findings, the area of JE in SPF mice was significantly greater than that in GF mice (P <0.05). In addition, the JE and PCT in SPF mice showed greater migration of neutrophils and higher expression of ICAM‐1, FGFR‐1, MMP‐1, and MMP‐8 than those in GF mice (P <0.05). Furthermore, the density of collagen in PCT in SPF mice was lower compared to GF mice (P <0.05). Conclusion: These results indicate that commensal bacteria induced a low‐grade inflammatory state in JE and that such conditions may contribute to degradation of collagen in PCT in mice.     

Using phage Lytic Enzymes to Control Pathogenic Bacteria

Our laboratory has developed phage lytic enzymes to prevent infection by specifically destroying disease bacteria on mucous membranes and in blood. Enzymes specific for S. pneumoniae and S. pyogenes have been developed to be used nasally and orally to control these organisms in environments such as hospitals and nursing homes to prevent or markedly reduce serious infections by these pathogens. In addition, a B. anthracis-specific enzyme was developed to kill the vegetative forms of these bacteria in the blood of infected individuals. In animal studies, >80% of mice colonized mucosally or infected intravenously with pathogenic bacteria were decolonized or survived after a single enzyme treatment delivered to the same site of colonization or infection.     

牙周非手术治疗对慢性肾病伴牙周炎患者牙周状况及血清C反应蛋白的影响

目的：探讨牙周非手术治疗对慢性肾病（CKD）伴牙周炎患者牙周状况及血清C反应蛋白（CRP）的影响。方法：分两组,A组为无全身严重疾病的牙周炎中老年患者38例,B组为伴慢性肾病的牙周炎中老年患者46例,两组均进行牙周非手术治疗,于牙周治疗前、后3个月分别检测其血清CRP及牙周指标。结果：A组治疗前牙周状况与B组相比,差异非常显著（P〈0.01）。两组患者治疗后牙周状况与治疗前均有改善,差异非常显著（P〈0.01）,A组的治疗效果好于B组,差异有显著性（P〈0.01）。治疗后A组患者血清CRP与治疗前有明显降低,差异非常显著（P〈0.01）,B组患者CRP与治疗前也有降低,差异有显著性（P〈0.05）。患者血清CRP与BOP、PD、AL等指标均呈正相关（P〈0.05）。结论：牙周非手术治疗可能通过改善牙周状况而降低慢性肾病伴牙周炎患者的血清CRP水平。     

Periodontal Therapy Effects on Nitrite Related to Oral Bacteria: A 6‐Month Randomized Clinical Trial

Background : Nitrite is a biologic factor relevant to oral and systemic homeostasis. Through an oral bacteria reduction process, it was suggested that periodontal therapy and chlorhexidine (CHX) rinse could affect nitrite levels, leading to negative effects, such as an increase in blood pressure. This 6‐month randomized clinical trial evaluated the effects of periodontal therapeutic protocols on salivary nitrite and its relation to subgingival bacteria. Methods: One hundred patients with periodontitis were allocated randomly to debridement procedures in four weekly sections (quadrant scaling [QS]) or within 24 hours (full‐mouth scaling [FMS]) in conjunction with a 60‐day CHX (QS + CHX and FMS + CHX), placebo (QS + placebo and FMS + placebo), or no mouthrinse (QS + none and FMS + none) use. Real‐time polymerase chain reaction determined total bacterial, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Streptococcus oralis, and Actinomyces naeslundii levels. Salivary nitrite concentration was determined with Griess reagent. Data were analyzed statistically at baseline and 3 and 6 months by analysis of variance, Kruskal–Wallis, Mann–Whitney U, and Spearman correlation tests (P <0.05). Results: Nitrite concentrations did not tend to change over time. Regarding CHX use, there was a negative correlation between nitrite and total bacterial load at 6 months (FMS + CHX) and one positive correlation between P. gingivalis and nitrite at baseline (QS + CHX). Independently of rinse type, in the FMS group, nitrite correlated negatively with several microbial parameters and also with a higher percentage of deep periodontal pockets. Conclusions: The relationship between nitrite and bacterial levels appears weak. Short‐term scaling exhibited a greater influence on nitrite concentrations then long‐term CHX use.     

牙周基础治疗后维持期菌斑控制的效果观察

目的　评价菌斑控制预防牙周疾病的效果。方法　随机选择 4 0例牙周疾病患者 ,分为菌斑控制组 (2 3例 )及对照组 (17例 )。于全口洁治、刮治和根面平整 (SRP)后 2周 (基线 )、基线后 12、2 4、4 8周检测菌斑指数 (PLI)、龈沟出血指数 (SBI)、探诊深度 (PD)及临床附着丧失 (CAL)。结果　菌斑控制组基线后 12、2 4、4 8周时PLI、SBI、PD显著低于对照组 (P <0 .0 5 ) ,菌斑控制组基线后 4 8周时CAL显著低于对照组 (P <0 .0 5 )。结论　菌斑控制能够有效地预防牙周疾病的发生、发展。     

四环素对人牙周膜成纤维细胞的生物学作用

目的探讨四环素对体外培养的人牙周膜成纤维细胞(I1PDLFs)的生物学作用。方法将不同浓度的四环素(1,5,20,100,500,2 500习ml)加人体外培养的HPDLFs中,孵育2d后,在倒置显微镜下观察其对细胞形态的影响,并用M,1法、考马司亮蓝法及“H-TdR掺人法,分别检测四环素对细胞的增殖活性、蛋白合成及DNA合成的影响。结果在1 -. 100 pg/ml的浓度范围内,细胞形态呈正常的梭形或纺锤形。在20- 100留ml的浓度范围内,四环素可促进HPDLFs的增殖及生物合成(P < 0.01)。当四环素的浓度增至2 500 lcg/ml,不仅使细胞的镜下形态发生了明显改变,而且严重抑制了细胞的生物学活性。结论在合适的浓度范围内,四环素能促进HPDLFs的增殖及生物合成,而浓度过高则具有细胞毒性。     

烤瓷冠颈缘密合度和位置对牙周健康的影响

目的探讨烤瓷冠颈缘密合度和位置对冠桥基牙牙周组织健康的影响。方法收集已接受烤瓷冠桥修复的患者46例,共63颗基牙,按冠颈缘处是否卡探针分为颈缘密合组和颈缘不密合组,又按冠颈缘位置分为龈上组、齐龈组和龈下组。检查各基牙的菌斑指数、龈沟出血指数及探针深度,并进行统计学分析。结果颈缘不密合组烤瓷冠基牙的龈沟出血指数高于颈缘密合组(P<0.05),龈下组高于龈上组和齐龈组(P<0.05)。结论为了基牙牙周组织健康,烤瓷冠的颈缘应尽可能密合,且边缘不宜做在龈下。     

儿童猛性龋病原菌母子传播研究

目的 :探讨幼儿猛性龋病原菌母子传播途径。方法 :随机选择可获得变形链球菌群 (MS)纯培养的 2～ 5岁猛性龋、非猛性龋及无龋儿童母子各 10对 ,进行DNA指纹实验 ,检测儿童牙菌斑和母亲唾液中MS菌株的遗传相似性 ,并检查母亲唾液MS水平。结果 :猛性龋儿童MS菌株基因型与母亲的一致性为 70 % ,与非猛性龋和无龋儿童(均为 6 0 % )无显著差异 ;但猛性龋儿童MS基因型数目显著多于非猛性龋和无龋儿童 (P <0 0 5 )。猛性龋儿童母亲唾液变链菌水平与非猛性龋和无龋儿童母亲相似 ,但唾液远缘链球菌水平及DMFT均数显著高于无龋儿童母亲。结论 :母亲是儿童MS的主要来源 ;幼儿猛性龋与母亲的DMFT计数及唾液远缘链球菌水平成正相关 ,母子传播对幼儿猛性龋的发生具有一定作用。     

奥硝唑和培氟沙星不同配伍对牙周病原菌体外抗菌作用

目的:了解奥硝唑和培氟沙星不同比例配伍对牙周病原菌体外抑菌效果。方法:1)奥硝唑和培氟沙星各自分为6水平,测量两种药物不同比例水平混合后对牙龈卟啉单胞菌,具核梭杆菌,中间普氏菌,消化链球菌标准菌株的抑菌指标变化,通过统计检验找出奥硝唑和培氟沙星不同配伍抑菌指标的无差别比例范围,并找出合适比例。2)检测两种药物以及其合适的比例对厌氧菌标准菌株和42株临床分离的非厌氧菌的M IC和M IC50。结果:牙龈卟啉单胞菌,具核梭杆菌,中间普氏菌,消化链球菌对奥硝唑和培氟沙星不同配伍所测指标的无差别范围分别是6∶1~1∶2、6∶1~2∶3、6∶1~2∶3、6∶1~1∶1。结论:两种药物混合对细菌的抑菌效果以2∶3为佳,但有待进一步动物实验和临床验证。