三种根管内厌氧菌荚膜对人牙龈成纤维细胞的生长抑制作用

本文研究了三种根管内厌氧菌纯化荚膜对人牙龈成纤维细胞的抑制作用。结果显示牙龈卟啉菌和中间型普里沃氏菌纯化荚膜可以明显抑制成纤维细胞ＤＮＡ合成，使细胞、细胞核面积增大，但细胞未出现死亡、溶解现象，两种荚膜对成纤维细胞的作从里浓度依赖性，以牙龈卟啉菌荚膜作用最强，牙髓卟啉菌荚膜作用不明显。纯化荚膜对成纤维细胞的作用主要是诱导其过早老化。     

3种口腔厌氧菌荚膜对人牙龈成纤维细胞增殖抑制作用

采用细胞计数法研究了３种口腔厌氧菌荚膜对人牙龈成纤维细胞的增殖抑制作用。结果显示：牙龈卟啉菌荚膜和中间型普里沃氏菌荚膜具有明显抑制作用，并呈浓度依赖性，作用２４ｈ后抑制作用呈不可逆性。牙髓卟啉菌荚膜对人牙龈成纤维细胞无明显抑制作用。实验结果提示：口腔厌氧菌荚膜在牙周病、尖周病早期病变中可能起着重要作用     

AP-PCR法鉴别中间普里沃菌和变黑普里沃菌

目的　用引物OPA - 13的随机引物聚合酶链法 (arbitrarilyprimedpolymerasechainreaction ,AP -PCR)区分中间普里沃菌 (Prevotellaintermedia ,Pi)和变黑普里沃菌 (Prevotellanigrescens ,Pn)。 方法　用引物OPA - 13,采用AP -PCR法分析 97株来自 2 5例成年人牙周炎 (adultperiodontitis,AP)的Pi和 4 9株来自 2 1例AP的Pn的基因型。结果　 97株Pi中仅有 1株没有 90 0bp的特异性片段 ,4 9株Pn中也只有 1株没有产生 1.3kb的特异性片段。牙龈卟啉单胞菌 (Pg)ATCC 332 77,PgW 83,产黑色素普里沃氏菌ATCC 2 5 84 5 ,不解糖卟啉单胞菌ATCC 2 5 2 6 0 ,躯体普里沃氏菌ATCC 335 4 7,小齿普里沃氏菌ATCC 33185均不产生相关片段。结论　用引物OPA - 13的AP -PCR法可以区分Pi和Pn。     

PCR和核酸探针在临床尖周炎检测中应用的对比研究

采用聚合酶链反应和核酸探针杂交技术，检测了１００例临床尖周炎患牙根管内标本中牙龈卟啉菌的分布，并对两种方法进行了对比研究。结果显示：１；ＰＣＲ对尖周炎中Ｐｇ的检出率为７４％，核酸探针为７６％，两者的总符合率达到９４％；２．在两种方法检测的所有项目对比组之间均未见显著性差异；３．Ｐｇ与尖周炎临床症状中的自发痛，叩痛，臭味和尖周肿胀有关。     

应用聚合酶链式反应检测国人10种牙周病可疑致病菌

目的 :应用聚合酶链式反应分别检测国人不同牙周情况者龈下菌斑中 10种牙周可疑致病菌 ,观察其分布特点 ,并初步分析不同的细菌组合与牙周病的关系。方法 :从 3组对象 :健康组 ,龈炎组和牙周炎组中采取 12 4例龈下菌斑 ,提取DNA ,分别用 10种牙周病可疑致病菌的特异引物 ,采取聚合酶链式反应(PCR)扩增 16SrDNA片段来鉴定细菌种类。用统计软件分析细菌与各项临床指标的关系。结果 :经 χ2 检验 ,龈炎组和牙周病组牙龈卟啉菌的检出率高于健康组 (P <0 .0 5) ,牙周病组福塞氏类杆菌、中间型普里沃氏菌、齿垢密螺旋体 ,变黑普里沃氏菌的检出率高于健康组和龈炎组 (P <0 .0 5)。经Logistic回归进一步分析 ,中间型普氏沃氏菌、齿垢密螺旋体和变黑普里沃氏菌与牙周病关系更为密切 ;中间型普里沃氏菌、变黑普里沃氏菌和生痰二菌化碳噬纤维菌与附着丧失有关 ,而Pi和Td对探诊出血影响较大。结论 :我国人群的牙周病可疑致病菌的分布有自已的特点。     

抗牙龈卟啉单胞菌IgY的制备及抑菌效果

目的:使用牙龈卟啉单胞菌(P.g)诱导产蛋母鸡特异性IgY抗体产生及制备,特异性IgY抗体抑制P.g及其它牙周病病因菌生长.方法:采用免疫接种、水稀释、盐析、液体培养抑菌及ELISA等方法,诱导、提纯IgY抗体,抑制P.g及其它牙周病病因菌生长.结果:诱导产生的IgY抗体经硫酸铵盐析提取纯度达87.6%～89.1%,IgY特异性结合牙龈卟啉单胞菌抗原的结合效价1∶ 1 600.制备的抗牙龈卟啉单胞菌IgY抗体与牙龈二氧化碳噬纤维菌、中间普氏菌、伴放线放线杆菌、具核梭杆菌等牙周病致病菌的交叉免疫反应抗原结合效价分别为1∶ 800、1∶ 800、1∶ 6 400、1∶ 12 800.抗牙龈卟啉单胞菌IgY在5.0、1.0、0.1 g/L时,分别与牙龈卟啉单胞菌、牙龈二氧化碳噬纤维菌、伴放线放线杆菌、中间普氏菌、具核梭杆菌、粘性放线菌、变形链球菌等厌氧菌在(1×108) CFU/L和(5×108) CFU/L时培养24 h和72 h均有不同程度的抑制其生长作用.结论:牙龈卟啉单胞菌免疫产蛋母鸡诱导产生的特异性IgY抗体在一定的浓度内有抑制牙龈卟啉单胞菌生长,以及抑制多种牙周病致病菌生长的作用.牙龈卟啉单胞菌与这些牙周病病因均存在着共同抗原,其可能具有防治牙周病的前景.     

厌氧菌荚膜对破骨细胞形成的影响

目的：观察３ 种厌氧菌荚膜对人骨髓长时间培养中破骨细胞形成和功能活化的影响。方法：采用合法堕胎５ 个月胎儿长干骨骨髓单个核细胞,在 Ｇ Ｍ－ Ｃ Ｓ Ｆ、马血清和荚膜存在下培养３ 周,观察破骨细胞的形成。结果：在所有培养中由单个核细胞融合形成的多核细胞多数具有破骨细胞特征：多核、细胞膜呈皱褶状、抗酒石酸盐酸性磷酸酶染色阳性,在牙本质片上可形成吸收陷窝等。牙龈卟啉菌荚膜组和中间型普里沃氏菌荚膜组中,抗酒石酸盐酸性磷酸酶染色阳性的多核和单个核细胞数和牙本质片上形成的吸收陷窝明显增多。牙髓卟啉菌荚膜组与对照组差异不明显。结论：厌氧菌荚膜可能参与了牙周病、尖周病后期的骨组织吸收。     

慢性牙周炎患者牙周袋内硫化物水平与厌氧细菌分布的相关性研究

目的:探讨慢性牙周炎患者牙周袋内硫化物水平(sulfide levels in periodontal pockets,SUL)与牙龈卟啉单胞菌、中间普氏菌、伴放线放线杆菌分布的相关性.方法:用perio2000 system金刚探针牙周诊断仪测定慢性牙周炎患者SUL,采用PCR方法检测龈下菌斑中牙龈卟啉单胞菌、中间普氏菌和伴放线放线杆菌.结果:慢性牙周炎患者随着牙周袋内SUL浓度的增加牙龈卟啉单胞菌、中间普氏菌的检出率逐渐增加,相关系数分别为0.812和0.651(P<0.05);SUL阳性位点与阴性位点中牙龈卟啉单胞菌的检出率分别是为85.6%、26.7%,中间普氏菌的检出率分别为95.2%、53.3%.SUL阳性位点中牙龈卟啉单胞菌和中间普氏菌的检出率明显高于SUL阴性位点;在80.9%的SUL阳性位点中牙龈卟啉单胞菌与中间普氏菌共存.SUL阳性位点与阴性位点均未检出伴放线放线杆菌.结论:慢性牙周炎患者SUL与牙龈卟啉单胞菌和中间普氏菌分布关系较为密切.     

二甲胺四环素胶原制剂体外抗菌研究

目的研究胶原蛋白为载体复合二甲胺四环素制成的牙周缓释制剂的抗菌效果,以期寻找辅助治疗牙周炎的新制剂。方法采用杯碟法对含20mg/g盐酸二甲胺四环素的胶原牙周缓释剂和派丽奥软膏进行牙周常见致病菌的抑菌实验,测定最小抑菌浓度（MIC）和抑菌环直径。菌珠选用国际标准菌株牙龈卟啉单胞菌、中间型普里沃氏菌、巨核梭形杆菌、伴放线放线杆菌和粘性放线菌。结果胶原牙周缓释制剂和派丽奥软膏对各实验菌株均有抑菌作用,牙龈卟啉单胞菌、中间型普里沃氏菌、巨核梭形杆菌、伴放线放线杆菌的MIC为0.31mg/L,粘性放线菌的MIC为1.2mg/L。2种药物比较抑菌效果无显著性差异（P〉0.05）。结论胶原牙周缓释制剂对牙周主要致病菌具有良好的抑制作用。     

牙周炎患者拔牙前后血清抗牙龈卟啉菌抗体水平的变化

用酶联免疫吸附测试法检测了７例成人牙周炎（ＡＰ）患者全口拔牙前及拔牙后１、２、３、１２及１８个月的血清抗牙龈卟啉菌（Ｐｇ）抗体水平的变化，并与６名牙周健康成人血清进行对照。结果表明，７例ＡＰ患者全口拔牙后血清抗ＰｇＩｇＧ抗体均逐月下降且明显低于拔牙前水平，但在拔牙后１８个月时仍明显高于对照组水平。血清抗体水平基本以相近似的速率下降，其中拔牙后１个月时的下降率较低。其下降率与牙周病各临床指数之间未显示明显的相关性。拔牙前的抗体水平与全口存留牙的深牙周袋率之间呈正相关趋势。本研究结果提示，在Ｐｇ感染去除后，机体对Ｐｇ抗原所产生的抗体逐渐下降，以牙周病患者血清抗ＰＧＩｇＧ水平作为该菌感染存在的诊断指标之一，值得进一步研究。     

急、慢性根尖周炎患牙根管内内毒素水平的分析测定

目的　比较急、慢性根尖周炎患牙根管内的内毒素水平并探讨内毒素与患牙尖周瘘管的关系。方法　选择急性根尖周炎、慢性根尖周炎根尖暗影直径<2 mm、根尖暗影直径>2 mm有瘘道和无瘘道的患牙各10例,采用产色基质鲎试剂法检测根管内内毒素含量。结果　慢性根尖周炎根尖暗影<2 mm的患牙,根管内内毒素水平明显低于急性根尖周炎及慢性根尖周炎根尖暗影>2 mm(有或无瘘道)的患牙,其差异有统计学意义(P<0·01)。结论　内毒素可能与尖周炎临床症状及根尖骨吸收程度密切相关。     

Inflammatory cytokine production and specific antibody responses against possible causative bacteria in patients with multilesional periapical periodontitis

We examined the induction of inflammatory cytokines (including interleukin-1, interleukin-6, interleukin-8, and tumor necrosis factor-alpha) by several species of possible causative bacteria in periapical periodontitis. Assays were done on human whole blood cultures from patients with differing numbers of periapical lesions; those having radiographically clear periapical lesions in 10 or more teeth (high lesion group), in one or two teeth (low lesion group), and healthy volunteers having no periapical lesions (no lesion group). Prevotella melaninogenica ATCC 25845 induced interleukin-6 more strongly in subjects from the high lesion group than in the other groups. To ascertain the degree of sensitization by test bacteria, we examined the reactivities of antibodies in serum and saliva from the six subjects to different bacterial species. Porphylomonas gingivalis cells reacted strongly with sera from the high lesion group. Thus, Prevotella melaninogenica and Porphylomonas gingivalis may be involved in multilesional periapical periodontitis by inducing specific cytokines and/or humoral immune responses.     

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目的应用聚合酶链式反应-变形梯度凝胶电泳（PCR—DGGE）技术检测慢性根尖周炎患牙根管内中间普菌和链球菌定植情况,分析根管内细菌与患牙症状间关系。方法2011年12月至2013年5月于北京大学深圳医院口腔科就诊的27例慢性根尖周炎患牙根管内细菌样本,提取DNA,利用16SrDNA引物进行PCR—DGGE技术分析。结果27例共检出细菌菌属17种。中间普菌在17例有症状组中检测出16例（94．1％）,在10例无症状组中检测出6例（60．0％）,两组检出率差异有统计学意义（P〈0．05）。链球菌在17例有症状组中均未检测出,在10例无症状组中检测出4例（40．0％）,两组检出率差异有统计学意义（P〈0．05）。结论慢性根尖周炎患牙以厌氧菌感染为主,根管内中间普菌、链球菌与临床症状相关。     

Detection of bacteria in endodontic samples by polymerase chain reaction assays and association with defined clinical signs in Italian patients

BACKGROUND/AIMS: The presence of selected bacteria (Enterococcus faecalis, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, Treponema denticola) in infected root canals was studied using polymerase chain reaction (PCR) assays, and the association of bacteria with clinical signs of endodontic disease was assessed. The null hypothesis, that no difference could be observed between clinical signs of apical periodontitis and a specific bacterial strain, was tested. METHODS: Microbial samples were obtained from 62 teeth in 54 patients with endodontic disease. For each tooth, clinical data including patient symptoms were collected. Teeth were categorized by diagnosis as having acute apical periodontitis (AAP, teeth with clinical symptoms but no periapical radiolucency, n=22), chronic apical periodontitis (CAP, teeth with radiolucency but no clinical symptoms, n=15) or exacerbated apical periodontitis (EAP, teeth with symptoms and radiolucency, n=25). Seventy-one percent of cases were primary endodontic infections, and 29% were recurrent ('secondary') endodontic infections (failing cases). PCR assays were used to detect the presence of the selected bacteria. RESULTS: T. denticola and E. faecalis were each detected in 15 of 62 samples (24%), P. gingivalis in 8 samples (13%), P. intermedia in 5 samples (8%), and T. forsythensis in 4 samples (7%). T. denticola was detected in 56% of teeth with EAP. E. faecalis was found in 60% of teeth with CAP and in 72% of teeth with secondary infection. Statistical analysis demonstrated an association of CAP and secondary endodontic infection with the presence of E. faecalis. (P<0.01). EAP was associated with the presence of T. denticola (P<0.01). CONCLUSION: T. denticola was associated with symptomatic endodontic disease in the presence of apical bone resorption. E. faecalis was associated with treatment failures. We suggest that these species may play critical roles in endodontic pathology.     

MTA应用于显微根尖手术治疗慢性根尖周炎的效果观察

目的 观察三氧化矿物凝聚体(mineral trioxide aggregate,MTA)应用于显微根尖手术治疗慢性根尖周炎的效果.方法 无法行常规根管再治疗的慢性根尖周炎患者64例91颗患牙,随机分为观察组和对照组.观察组患者32例48颗,行显微根尖手术,应用MTA进行倒充填治疗.对照组患者32例43颗,行传统外科根尖手术联合银汞合金充填治疗.术后每隔3个月定期复诊,随访12个月,通过临床和X线检查评估根尖周病损愈合情况,进行疗效判定.结果 观察组痊愈27颗,改善17颗,成功率91.67%(44/48);对照组痊愈19颗,改善12颗,成功率72.09%(31/43).观察组治疗成功率明显高于对照组(x2=5.997,P=0.014).结论 MTA应用于显微根尖手术治疗慢性根尖周炎效果满意.     

Studies into the microbial spectrum of apical periodontitis

This study examined the variety of obligate and facultative anaerobic bacterial species recovered from cases of acute apical periodontitis. A total of 19 root canal samples and 24 periapical granuloma samples were taken from patients suffering pain and discomfort. Bacteria were identified by applying the following techniques: culturing on various media, Gram-staining and using commercially available biochemical test strips. In addition, Prevotella intermedia and Porphyromonas endodontalis were differentiated on a molecular genetic level using species-specific oligodeoxymicleotide probes. The most frequently identified bacteria were Prevotella intermedia, Bifidobacterium spp., Streptococcus sanguis. Streptococcus milleri-group and Bacteroides spp. Obligate anaerobes occured at a rate of 82.3%, and the average number of isolates was 6.4 per sample.     

The concentration of prostaglandin E2 in human periradicular lesions

Prostaglandins (PG) have been implicated in the genesis of periapical lesions. Periapical specimens from patients with clinical signs and symptoms of chronic and acute apical periodontitis were obtained and immediately frozen in liquid nitrogen. Periradicular tissues from unerupted third molars were frozen and used as controls. The concentration of PGE2 was determined by radioimmunoassay. Low levels of PGE2 were found in the control tissues as compared with those detected in chronic and acute lesions. Significantly higher levels of PGE2 were found in acute lesions than those found in chronic lesions. The results show that acute lesions have higher concentrations of PGE2 than chronic lesions and confirm the role of prostaglandins in the pathogenesis of human periapical lesions.     

miR-146a-5p在慢性根尖周炎病损组织中的表达及临床意义

目的:比较慢性根尖周炎病损组织和健康牙周膜组织中miR-146a-5p的相对表达水平,探讨miR-146a-5p在慢性根尖周炎发病中的作用及临床意义。方法:收集16例诊断为慢性根尖周炎患牙的根尖周组织作为病例组,8例因正畸拔除的健康牙的牙周膜作为对照组,采用HE染色检测样本的炎症浸润程度,采用实时荧光定量PCR(real-time PCR,RT-PCR)检测miR-146a-5p的表达。所有数据采用SPSS18.0软件包进行统计学分析。结果:HE染色结果可见对照组中无明显炎症细胞浸润,病损组织中可见大量炎症细胞浸润;RT-PCR实验结果显示,病例组与对照组均有miR-146a-5p的表达,且miR-146a-5p在慢性根尖周炎病损组织中的相对表达量明显高于对照组健康牙周膜组织,差异具有统计学意义(P＜0.05)。结论:miR-146a-5p与慢性根尖周炎的发生发展密切相关。     

Symptomatic and asymptomatic apical periodontitis associated with red complex bacteria: clinical and microbiological evaluation

In this study, the association of red complex (RC) bacteria that include Treponema denticola, Tannerella forsythia and Porphyromonas gingivalis with acute, exacerbated or chronic apical periodontitis was evaluated. Seventy-one patients with periapical disease were evaluated by clinical examination and microbiological samples obtained from the root canals were analyzed by a polymerase chain reaction assay. Twenty-one (29.6%) samples were positive for RC bacteria, with T. denticola, T. forsythia and P. gingivalis being detected in 14 (19.7%), 10 (14.1%) and 6 (8.5%) samples, respectively. RC bacteria were mainly associated with acute apical periodontitis (29.2%) and phoenix abscess (63.2%), while they were only sporadically detected (7.1%) in patients with chronic apical periodontitis. Generally, RC bacteria were associated with pain and a higher frequency of intracanalar/intrasulcular pus drainage. Involvement of RC bacteria in symptomatic periapical disease should be suspected in the presence of particularly severe clinical pain and pus drainage.     

CBCT和根尖放射线片诊断根尖周炎的对比性研究

目的：比较应用CBCT和根尖放射线片对慢性根尖周炎的严重程度及病变范围进行评估的差异性,评价CBCT在慢性根尖周病变的诊断、治疗方案的确定及预后等方面的临床价值。方法：选取临床上有根尖周炎症状的53例患者（96颗牙）,均拍摄根尖放射线片和CBCT,分别由2位专家采用单盲法进行放射线影像学诊断,比较两种影像学方法对根尖周炎的存在及病变范围评估的差异性。结果：根尖放射线片发现82.3%,CBCT发现100%的患牙存在根尖周病变。并且在两者都诊断出根尖炎时,CBCT的PAI值明显高于根尖片。结论：在诊断慢性根尖周炎方面,CBCT扫描与根尖放射线片相比具有更高的敏感性和精确度。和根尖放射线片比较,CBCT对临床上根尖周炎的诊断、严重程度及预后判断都更有优势,从而能够更好的指导临床治疗。