牙周致病菌的共聚及其对人工牙根面黏附力的影响

目的比较具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌等牙周病致病菌彼此之间的共聚力大小,观察四者在具核梭杆菌介导下对人工牙根面黏附力的影响,了解牙周生物膜结构中细菌间可能存在的相互作用。方法目测具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌彼此间的共聚力,以放射性核素闪烁计数四者在具核梭杆菌黏附和未黏附状况下对胶原包被羟磷灰石(c-HA)的黏附间是否存在着差异。结果具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌彼此间存在着共聚作用,其中,具核梭杆菌与牙龈卟啉单胞菌、牙龈卟啉单胞菌与中间普雷沃菌间的共聚度均可达4度,具核梭杆菌与其他三菌间的共聚度均大于3度。牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌在具核梭杆菌黏附的状况下对c-HA的黏附率高于其在具核梭杆菌未黏附时的黏附率,具核梭杆菌在未黏附的状况下对c-HA的黏附率高于其在黏附后的黏附率。结论具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌彼此间均存在共聚关系,具核梭杆菌可能对其他牙周病致病菌定植于牙菌斑起到了桥梁作用。     

牙周可疑致病菌对胶原包被羟磷灰石黏附的体外实验研究

目的比较对牙根面具有黏附能力的具核梭杆菌、牙龈卟啉单胞菌、中间普氏菌和伴放线菌嗜血菌对胶原包被的羟磷灰石实验膜（C- HA）的黏附能力,初步探讨以上牙周可疑致病菌在牙根表面形成菌斑生物膜的能力。方法采用同位素闪烁计数法测定上述4种细菌黏附至C- HA表面的黏附量及黏附率,比较其黏附能力。结果培养相同时间,不论是培养24 h还是培养48 h,4种不同细菌两两比较,具核梭杆菌ATCC 10953和牙龈卟啉单胞菌ATCC 33277对C- HA表面黏附率的差异无统计学意义;中间普氏菌ATCC 25611和伴放线菌嗜血菌ATCC 29523的黏附率之间差异也无统计学意义,但是具核梭杆菌ATCC 10953和牙龈卟啉单胞菌ATCC 33277对C- HA表面的黏附率显著高于中间普氏菌ATCC 25611和伴放线菌嗜血菌ATCC 29523（P<0.001）。同一种细菌,在培养不同时间即培养24 h和48 h,对C- HA表面黏附率的差异均无统计学意义。结论不同的牙周可疑致病菌对胶原包被的羟磷灰石的选择性黏附作用不同,具核梭杆菌和牙龈卟啉单胞菌对胶原有较强的亲和作用,在细菌的局部定植过程和牙周炎的进展和复发中可能发挥重要作用。     

牙周病原菌粘附共聚机制的研究进展

牙周病原菌通过粘附共聚后形成了生物膜.由于牙周生物膜难以清除,使得牙周炎难以控制.本文就牙周病原菌的粘附共聚机制作一综述,旨在更好地认识和研究牙周炎的病因机制.     

舌侧矫治器对牙周致病菌的影响

目的研究舌侧矫治器对患者牙周临床指标和牙周致病菌的影响。方法收集成年正畸治疗患者55例资料,28例使用颊侧矫治器作为对照组,27例使用舌侧矫治器作为试验组,于治疗前和治疗6个月后,分别记录菌斑指数、龈沟出血指数、探诊深度,PCR检测龈下菌斑中牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)、伴放线放线杆菌(Actinobacillus actinomycetemcomtans,Aa)、福赛斯坦氏菌(Tannerella forsythensis,Tf)3种牙周致病菌的检出率。结果治疗6个月试验组菌斑指数、龈沟出血指数、探诊深度分别为2.36±0.71、2.05±0.49、(3.43±0.56)mm,对照组分别为1.86±0.44、1.67±0.25、(2.87±0.74)mm,2组间差异均有统计学意义(P<0.05);试验组Pg、Aa检出率分别为37.0%和22.2%,对照组的Pg、Aa检出率分别为14.3%和10.7%,试验组高于对照组(P<0.05)。结论舌侧矫治器,较颊侧矫治器,对牙周临床指标影响更大,可造成更多的牙周致病菌聚集。     

牙周可颖致病菌对血液链球菌产生过氧化氢的影响

目的：了解牙周可颖致病菌对血液链球菌产生过氧化氢的影响，探讨血液链球菌产生的过氧化氢在牙周微生态环境中的应用。方法：采用酚红还原－微量反应板法检测粘性放线菌（Ａｖ）与血液链球菌混合孵育的上清中的过氧化氢含量变化。结果：在不加外源性糖作为底物时，仅Ｆｎ组有高于对照组的过氧化氢，Ｐｇ、Ｐｉ、Ａａ组均未能测出。在有葡萄糖、蔗糖、麦芽糖、乳糖存在时，Ｐｉ、Ａａ组无氧化氢积累，Ｐｇ、Ａｖ、Ｆｎ组能检出的过氧     

荷叶提取物对牙周主要致病菌的抑制作用

荷叶提取：干燥粉碎的荷叶水煎2次，合并水煎液，浓缩至适量，用正丁醇萃取2次，正丁醇萃取液减压浓缩至干，正丁醇提取后的水层浓缩干燥后用40％乙醇回流提取3次，过滤，滤液减压浓缩至干。正丁醇提取物、40％乙醇提取物和40％乙醇不溶物均在70℃真空干燥后供药理筛选。     

牙周致病菌内毒素耐受的研究进展

内毒素耐受(endotoxin tolerance)是指先前的脂多糖(lipopolysaccharide,LPS)刺激使机体或体外培养的细胞对后续刺激反应性降低的一种现象,可能导致炎症因子释放的减少,进而在牙周炎发生发展过程中发挥重要作用。本文就牙周致病菌内毒素耐受的作用和机制的研究进展作一综述。     

臭氧水溶液对牙周可疑致病菌作用的研究

目的：评价臭氧水溶液对常见牙周可疑致病菌的杀菌效果。方法：采用细菌悬液定量实验法,测定不同浓度的臭氧水溶液对牙龈卟啉单胞菌（P．g）ATCC33277、伴放线菌嗜血菌（H．a）ATCC29522、具核梭杆菌（F．n）ATCC10957和牙龈卟啉单胞菌临床分离株作用30、60、90、120 s 的杀菌率,阳性对照组采用不同浓度的过氧化氢溶液,阴性对照组采用蒸馏水。实验样本在厌氧培养72 h 后进行菌落计数并计算杀菌率。结果：臭氧水溶液对几种牙周可疑致病菌均有杀灭效果,且杀菌率随浓度的增加而提高（P ＜0．01）。对 P．g 标准株和临床分离株的杀菌率差异无统计学意义（P ＞0．05）。线性回归分析臭氧水溶液对3种细菌杀灭作用的浓度影响因素β值均大于0．95,时间影响因素β值均小于0．11。结论：臭氧水溶液对牙龈卟啉单胞菌、伴放线菌嗜血菌和具核梭杆菌具有浓度依赖性杀灭效果。     

应用PCR法对日本儿童口腔内4种牙周致病菌的检测

目的：应用PCR检测日本儿童口腔内牙龈卟啉单胞菌,伴放线放线杆菌,中间普氏菌以及福赛斯坦氏菌4种牙周病致病菌,并探讨检出结果与牙周临床检查参数之间的关系。方法：被检儿童为昭和大学齿科病院儿童牙病科就诊的儿童。随机选取全身健康的儿童37名作为被检对象,在上颌右侧中切牙和上颌右侧第一磨牙的近中唇、颊面采取龈上菌斑,应用PCR法检测牙周致病菌;临床检查包括口腔内检查、探诊深度及牙龈探诊后出血。结果：临床检查结果显示37名儿童均未患有牙周病。牙周致病菌检测结果显示Pg检出率为21.6%,Aa、Pi、Tf三菌种检出率为55%～58%。混合牙列期Aa、Pi、Tf检出率增高和恒牙列完成期检出率减低的倾向。Pg与牙龈探诊后出血之间未见相关,而Aa、Pi、Tf的检出率呈BOP阳性部位高于BOP阴性部位的倾向。结论：本研究结果显示6～18岁儿童龈上菌斑中高频度存在着牙周致病菌。为早期预防牙周病,对将来患牙周病危险性高的儿童进行早期筛查,并且从儿童时期采取预防措施非常必要。     

牙周可疑致病菌的传播性研究进展

现代分子生物学的快速进展为微生物的分类学研究提供了多种高敏感度的方法,使研究各类细菌的传播途径成为可能。近年来研究表明牙周可疑致病菌可交互传播,本文着重就其中与牙周疾病关系密切的相关细菌在人群中传播的可能性及途径的研究进展进行综述。     

Coaggregation profiles of the microflora from root surface caries lesions

Bacterial coaggregation reactions between different species and the auto aggregation of the same species are associated with the initiation and development of dental plaque and biofilms. As no such data is available on isolates from root caries lesions, we evaluated, by a visual, semi-quantitative scoring system and a spectrophotometric, quantitative assay, the coaggregation of 22 different wild-type microbial species comprising ten bacterial genera and a single Candida spp. The quantitative coaggregation assay we used proved to be a more sensitive method than the semi-quantitative, visual evaluation as the results yielded the percent coaggregation. Fusobacterium nucleatum, Lactobacillus acidophilus, Streptococcus bovis II/2 and Gemella morbillorum were observed having higher degrees of autoaggregation than the other examined strains. Significant levels of inter-species coaggregation was seen between: (1) Actinomyces spp. and Veillonella spp.; (2) Actinomyces israelii and Peptostreptococcus prevotii; (3) Campylobacter gracilis and Actinomyces spp.; (4) Prevotella intermedia and nine different species; and (5) Fusobacterium nucleatum and six other species. The single Candida albicans isolate did not coaggregate to a significant extent with any of the 21 bacterial isolates studied. Scanning electron microscopy observation of the coaggregation interactions between bacterial pairs having strong coaggregation reactions revealed varying adhesive patterns. Our findings on coaggregation amongst these isolates imply existence of multiple interactions between the coaggregation-inducing bacterial species in root caries. In particular, Actinomyces spp., Veillonella spp., Prevotella spp. and Fusobacterium spp. appear to play a significant role in this context.     

Antimicrobial activity of silver nitrate against periodontal pathogens

Metal ions were evaluated as potential antimicrobial agents suitable for local delivery in the oral cavity for the treatment of periodontitis. Silver nitrate, copper chloride, and zinc chloride were tested for antimicrobial activity in in vitro killing assays conducted in phosphate buffered saline with a series of oral bacteria including gram-negative periodontal pathogens and gram-positive streptococci. Copper and zinc salts failed to exhibit strong and consistent activity against periodontal pathogens. In contrast, silver at a concentration of 0.5 microg/mL produced a 3 log10 reduction in colony forming units (CFU)/mL or greater against all periodontal pathogens tested including Porphyromonas gingivalis, Prevotella intermedia, Prevotella denticola, Bacteroides forsythus, Fusobacterium nucleatum vincentii, Campylobacter gracilis, Campylobacter rectus, Eikenella corrodens, and Actinobacillus actinomycetemcomitans. In comparison, substantially higher concentrations of silver nitrate failed to kill oral streptococci. A silver nitrate concentration of 25 microg/mL produced log10 reductions in CFU/mL of 3.5-5 in killing assays performed in human serum against P. gingivalis, demonstrating the ability of silver to retain activity in a biological medium similar to that encountered in vivo in the periodontal pocket. These results identify silver nitrate, an antimicrobial that may possess advantages over traditional antibiotics, as a potential agent for controlled release local delivery in the oral cavity for the treatment of periodontitis.     

血链球菌在牙周病微生态防治中的作用研究--Ⅰ血链球菌对牙周可疑致病菌的拮抗作用

目的：对血链球菌全菌细胞和培养上清液的抗牙周可疑致病菌的作用进行研究。方法：分别采用常规打孔法和微量琼脂糖弥散法测定血链球菌全菌细胞和培养上清液的抗菌活性。结果：血链球菌JFr菌株全菌细胞菌悬液对中间普氏菌、牙龈卟啉单胞菌和具核梭杆菌的生长均有抑制作用。血链球菌培养上清液未见抑菌活性。丧失α-溶血能力的血链球菌变异株无这种抑菌作用。血链球菌JFr菌株对中间普氏菌临床分离株21—3的生长产生抑制作用的同时可见β-溶血反应。结论：血链球菌与牙周可疑致病菌之间的作用是相当复杂的，作用机制和结果在不同情况下可能有所不同。     

Short-term effect of full-mouth extraction on periodontal pathogens colonizing the oral mucous membranes

Abstract In this study, we investigate the prevalence of selected periodontal pathogens on the oral mucous membranes before and after full-mouth tooth extractions in patients with severe periodontitis. 8 patients were microbiologically examined 2 × before and 2 × after extraction; several locations on the oral mucous membranes, saliva, supra- and subgingival plaque, were sampled. Besides their presence in subgingival plaque, we detected before extraction on the mucous membranes Actinobacillus actinomycetemcomitans in 2 patients (mean 0.03%), Porphyromonas gingivalis in 6 patients (mean 9%), and Prevotella intermedia (mean 2%) and other Prevotella species (mean 7%) in all patients. At 1 and 3 months after extraction, A. actinomycetemcomitans and P. gingivalis could not be detected in any of these patients on the oral mucous membranes and in saliva, while from all patients still P. intermedia (mean 3%) and the other blackpigmented Prevotella species (mean 4%) could be isolated. These results indicate that the preferable habitat for A. actinomycetemcomitans and P. gingivalis is dental plaque in subgingival lesions. P. intermedia and the other blackpigmented Prevotella species can colonize the oral mucous membranes of edentulous patients irrespective of the presence of a subgingival microflora. We speculate that in periodontal patients the colonization of mucous membranes with P. gingivalis and A. actinomycetemcomitans is transient in nature and most likely the result of dissemination from the subgingival microflora. Thus it seems unlikely that edentulous patients constitute a reservoir of infection of P. gingivalis A. actinomycetemcomitans.     

Association between betel quid chewing, periodontal status and periodontal pathogens

The present investigation examined whether an association exists between betel quid chewing and signs of periodontal disease and determined the prevalence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis by polymerase chain reaction. The periodontal status of 34 betel quid chewers and 32 non-betel quid chewers were compared. A significantly higher prevalence of bleeding on probing was found in betel quid chewers than non-chewers among the subjects with higher plaque level, greater gingival inflammation, deeper probing depth or greater attachment loss. Also, the results suggested that betel quid chewers may harbor higher levels of infection with A. actinomycetemcomitans and P. gingivalis than non-betel quid chewers. The association persists after adjusting for severity of the clinical parameters. In conclusion, betel quid chewing was associated with a higher prevalence of bleeding on probing where higher clinical levels of disease existed, and with a likelihood of subgingival infection with A. actinomycetemcomitans and P. gingivalis.     

Comparison of profiles of key periodontal pathogens in periodontium and endodontium

Abstract – Despite the established anatomical relationship between the periodontal and pulpal tissues, bacterial migration between endodontium and periodontium is still under discussion. The objective of this study was an investigation of profiles of periodontal pathogens in pulpal and periodontal diseases affecting the same tooth by means of 16S rRNA gene directed polymerase chain reaction (PCR). 31 intact teeth with both pulp and marginal infections were investigated. The diagnosis was based on clinical and radiological examination. Samples were taken from the gingival sulcus or periodontal pocket, respectively, with sterile paper points before trepanation of the teeth. After trepanation sterile paper points and Hedstroem files were used for taking samples from the root canal. Specific PCR methods were used to detect the presence of the following pathogens: Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Eikenella corrodens, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola. In addition, quantitative competitive PCR was used to determine the total bacterial count of the samples. The investigated pathogens were proven to be present in the endondontium in all disease categories. Particularly in endodontic samples of "chronic apical periodontitis" and "chronic adult periodontitis" profiles of the periodontal pathogens were found. The results confirmed that periodontal pathogens often accompany endodontic infections and supported the idea that the periodontic-endodontic interrelationships should be considered as critical pathways which might contribute to refractory courses of endodontic or periodontal diseases.     

Regulation of matrix metalloproteinase production by cytokines,pharmacological agents and periodontal pathogens in human periodontal ligament fibroblast cultures

Matrix metalloproteinases (MMPs). produced by both infiltrating and resident cells of the periodontium, play a role in physiologic and pathologic events. It is recognized that an imbalance between activated MMPs and their endogenous inhibitors leads to pathologic breakdown of the extracellular matrix during periodontitis. To date, little is known about the regulation of MMP synthesis and secretion in human periodontal ligament fibroblasts (PDLFs). The purpose of this study was to examine the effects of cytokines, pharmacological agents (protein synthesis inhibitor and protein kinase C inhibitors) and predominant periodontal pathogens (Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis) on MMP production in human PDLFs using gelatin zymography. The gelatin zymograms revealed that the main gelatinase secreted by human PDLFs migrated at 72 kDa and represents MMP-2. Minor gelatinolytic bands were also observed at 92 kDa regions that correspond to MMP-9. We found that A. actinomycetemcomitans, P. gingivalis and IL-1alpha can elevate MMP-2 secretion in human PDLFs. These results indicate that periodontal pathogens and inflammatory cytokines play an important role in tissue destruction and disintegration of extracellular matrix in periodontal diseases. Thus, activation of MMPs may be one of the distinct host degradative pathways in the pathogenesis of periodontitis. In addition, H7, staurosporine, cycloheximide and TGF-beta could suppress MMP-2 production. Agents that target protein synthesis or the protein kinase C pathway in human PDLFs inhibit MMP-2 production, and such inhibition may contribute to the pathogenesis of periodontal inflammation. Taken together, these findings suggest a possible new therapeutic approach, involving the use of drugs that modify host-response mechanisms to suppress or inhibit MMP-mediated tissue destruction.     

光动力疗法对慢性牙周炎龈下牙周致病菌的影响

目的：应用PeriowaveTM光动力杀菌系统对慢性牙周炎患者进行治疗,通过龈下菌斑中牙周致病菌比例的变化,评价光动力疗法（photodynamic therapy,PDT）治疗慢性牙周炎的临床效果。方法：选取60名慢性牙周炎患者,分别给予SRP＋1次PDT（A组）、SRP＋2次PDT（B组）或单纯SRP（C组）治疗。利用real-time PCR技术检测A、B、C三组在治疗前、治疗后6周、治疗后12周龈下菌斑中牙周致病菌P.g、A.a、T.f所占比例的变化。结果：治疗后6周,A、B两组牙周致病菌P.g在总菌中的比例都有非常显著降低（p〈0.01）,C组有显著降低（p〈0.05）;治疗后12周,A、B组仍有非常显著的降低（p〈0.01）,与C组相比有非常显著差异（p〈0.01）,但A、B两组之间没有差异（p〉0.05）;而仅在治疗后12周,B组的A.a相对于总菌的比例与基线相比有显著降低（p〈0.05）,且这一变化显著大于A、C两组（p〈0.05）;在治疗后6周,A、B组T.f相对于总菌含量的下降与基线相比,明显大于C组（p〈0.05）,治疗后12周,A、B两组T.f相对于总菌的含量仍有非常显著的下降（p〈0.01）,但A组和B组之间都没有差异。结论：PDT对P.g、A.a和T.f3种牙周致病菌都有杀灭作用,但P.g、T.f对PDT更为敏感,PDT可以作为治疗慢性牙周炎的辅助方法。