急性根尖周炎患牙根管内厌氧菌的初步分析

目的：分析急性根尖周炎根管内细菌，为药敏试验奠定基础，方法：选择２７例急性根尖周炎患者作患牙根管内的厌氧菌分离培养和鉴定。结果：２７个感染根管内分离出厌氧菌６属，共６４株。结论：感染感染根管内的优势厌氧菌主要为类杆菌，梭杆菌，真细菌，丙酸杆菌，放线 菌和消化链球菌等。     

乳牙感染根管的菌丛分析

目的分析乳牙根尖周炎感染根管菌丛，为进一步防治提供依据。方法用直接酶法对８例乳牙急性根尖周炎、１４例乳牙慢性根尖周炎感染根管菌丛成分进行分析。结果共检出２４０株细菌，厌氧菌２００株，主要分布于消化链球菌、类杆菌、韦永氏菌、真细菌、丙酸杆菌、放线菌和梭杆菌。急性炎症组类杆菌、梭杆菌的检出率明显高于慢性组（Ｐ＜００５），主要差异在牙龈类杆菌和具核梭杆菌；慢性炎症组小韦永氏菌的检出率明显高于急性组（Ｐ＜０．０５）。结论乳牙急、慢性根尖周炎感染根管内是以厌氧菌为优势菌的混合感染。牙龈类杆菌、具核梭杆菌可能与乳牙根尖周炎的急性症状有关。小韦永氏菌在乳牙慢性根尖周炎中的作用不容忽视     

根管治疗失败病例根管内微生物检测及药敏试验

目的通过对根管治疗失败病例根管内微生物进行培养检测，了解失败病例根管内菌群特征，同时对检测出的细菌进行药敏试验，为临床根管治疗提供参考。方法选择86例根管治疗失败病例共86颗惠牙，去除根管内充填物后，对根管内细菌取样，进行培养和鉴定，用琼脂稀释法对根管内分离的优势菌进行药敏试验。结果根管治疗失败病例根管中微生物菌群组成以兼性厌氧菌为优势菌，主要以1-2种革兰阳性菌为主，肠球菌是最常检出的细菌。失败病例根管内检出的兼性及专性厌氧菌对青霉素G、甲醛甲酚、甲硝唑敏感。结论细菌与根管治疗失败密切相关，根管治疗失败病例根管内微生物组成有其独特性。临床应选择敏感性药物进行治疗。     

慢性根尖周炎感染根管内中间普氏菌基因多态性研究

目的:研究慢性根尖周炎感染根管内中间普氏菌是否存在基因多态性。方法:选择13例慢性根尖周炎患者,分别取其感染根管内样本,分离培养,经中间普氏菌特异引物PCR鉴定的克隆,再利用随机引物PCR(AP-PCR)检测其基因多态性。结果:13例慢性根尖周炎样本中3例分离出中间普氏菌,共95株,并检测出3种基因型,其中A、B、C样本各检出一种基因型。结论:慢性根尖周炎患者感染根管内中间普氏菌存在基因多态性。     

根管治疗期间急性发作与慢性根尖周炎患牙根管细菌组成比较

目的:比较根管治疗期间炎症急性发作及慢性根尖周炎患牙根管内8种厌氧菌检出情况,分析急性发作时根管内定植细菌种类及其相关性。方法:分别提取26例根管预备后约诊期间炎症急性发作患牙根管样本和23例慢性根尖周炎患牙根管样本,提取样本细菌DNA,利用细菌16S rRNA引物通过PCR扩增方法鉴定细菌。结果:慢性根尖周炎样本根管细菌检出率达100%(23/23),根管治疗期间急性发作样本细菌检出率为92.31%(24/26);产黑普氏菌、齿垢密螺旋体和直肠弯曲杆菌在急性发作样本中的检出率较慢性根尖周炎样本显著增高(P<0.05)。急性发作样本中牙龈卟啉菌与福赛氏类杆菌的检出显著相关(OR>2,P<0.05)。结论:根管内感染是根管治疗期间炎症急性发作的重要原因,厌氧菌在急性发作的发生中起重要作用。     

慢性根尖周炎根管中8种厌氧菌检出分析

目的应用16SrRNA-PCR技术检测慢性根尖周炎患牙根管内8种厌氧菌的定植情况,分析根管细菌与患牙临床症状的关系。方法采集23例慢性根尖周炎患牙根管样本,提取样本细菌DNA,用细菌16SrRNA引物通过PCR扩增细菌基因片段检测细菌种类。结果23例样本均检出有细菌存在,待检细菌检出率达73.91%(17/23)。其中检出率最高的是中间普氏菌(39.13%),其次是牙龈卟啉菌(30.43%)和福赛斯类杆菌(21.74%),变黑普氏菌、齿垢密螺旋体和啮蚀艾肯氏菌均为13.04%,伴放线放线杆菌有1例检出,直肠弯曲杆菌未检出。中间普氏菌在有自发痛症状组检出率高于无自发痛症状组(P<0.05),其他细菌检出率组间比较差异无显著性。结论慢性根尖周炎患牙根管内以厌氧菌感染为主;根管内中间普氏菌感染与患牙自发痛症状相关。     

慢性牙髓炎及根尖周炎感染根管微生物病因分析的研究现状

慢性牙髓炎及根尖周炎的感染根管内是以厌氧菌尤其是专性厌氧菌为主的混合感染，有关各种根尖周病感染根管内的细菌谱，不同门属的细菌类别与根尖周病的发生发展之间的相关性，以及上述相关问题的研究方法将在这里做一综述。     

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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。     

慢性根尖周炎患牙根尖生物膜的细菌学研究

目的：对根尖生物膜细菌进行分离、培养和鉴定，了解根尖生物膜细菌的种类、组成和来源。方法：通过根尖外科手术收集25颗慢性根尖周炎患牙的根尖生物膜样本，同时收集其中20颗患牙的根管细菌样本。所有样本均按常规接种、分离、纯化后，根据耐氧实验、细菌和菌落的形态、菌落的颜色、革兰染色和生化实验对细菌进行鉴定。统计分析比较根尖生物膜和根管细菌的检出率、构成比，并对不同临床状态下的根尖生物膜细菌检出进行分析。结果：细菌检出发现92．0％根尖生物膜样本细菌培养阳性，G^＋菌和G^-菌的检出率分别为80．0％和84．0％，专性厌氧菌和兼性厌氧菌的检出率分别为80．0％和44．0％；根管样本细菌检出情况与根尖样本基本一致。结论：根尖生物膜细菌检出率高，大多数样本为多种细菌混合感染；根尖生物膜细菌的种类、检出率、构成比与感染根管细菌基本一致。     

乳牙感染根管内专性厌氧菌药敏实验

采用反应板微量稀释法对乳牙根尖周炎感染根管内分离的优势菌４株及国际参考菌株４株进行７种药物体外敏感实验，结果显示，甲醛甲酚、甲硝唑、氯霉素是有效的抗根管厌氧菌的药物，盐酸林可霉素、头孢拉定对所有菌株亦显示出较强的抗菌效果，红霉素、盐酸去甲万古霉素药效较差     

三重抗生素糊剂对乳牙感染根管中微生物的影响

目的:探讨三重抗生素糊剂对乳牙根尖周炎不同分期感染根管中微生物样本的影响.方法:将2017年4月—2020年4月南京医科大学附属儿童医院口腔科收治的89例儿童乳牙根尖周炎患儿纳入研究,根据临床症状及根尖X线片,将患儿分为急性炎症组和慢性炎症组.收集感染根管内感染样本,对样本进行细菌鉴定、分离与纯化,分析2组患儿感染根管...     

Bacterial profile in primary teeth with necrotic pulp and periapical lesions

The objective of this study was to evaluate the bacterial profile in root canals of human primary teeth with necrotic pulp and periapical lesions using bacterial culture. A total of 20 primary teeth with necrotic pulp and radiographically visible radiolucent areas in the region of the bone furcation and/or the periapical region were selected. After crown access, 4 sterile absorbent paper points were introduced sequentially into the root canal for collection of material. After 30 s, the paper points were removed and placed in a test tube containing reduced transport fluid (RTF) and were sent for microbiological evaluation. Anaerobic microorganisms were found in 100% of the samples, black-pigmented bacilli in 30%, aerobic microorganisms in 60%, streptococci in 85%, gram-negative aerobic rods in 15% and staphylococci were not quantified. Mutans streptococci were found in 6 root canals (30%), 5 canals with Streptococcus mutans and 1 canal with Streptococcus mutans and Streptococcus sobrinus. It was concluded that in root canals of human primary teeth with necrotic pulp and periapical lesions, the infection is polymicrobial with predominance of anaerobic microorganisms.     

Microbiological analysis of infected root canals from symptomatic and asymptomatic teeth with periapical periodontitis and the antimicrobial susceptibility of some isolated anaerobic bacteria

The purpose of the present study was to investigate the correlation between the composition of the bacterial flora isolated from infected root canals of teeth with apical periodontitis with the presence of clinical signs and symptoms, and to test the antibiotic susceptibility of five anaerobic bacteria mostly commonly found in the root canals of symptomatic teeth against various substances using the E-test. Microbial samples were taken from 48 root canals, 29 symptomatic and 19 asymptomatic, using adequate techniques. A total of 218 cultivable isolates were recovered from 48 different microbial species and 19 different genera. Root canals from symptomatic teeth harbored more obligate anaerobes and a bigger number of bacterial species than the asymptomatic teeth. More than 70% of the bacterial isolates were strict anaerobes. Statistical analysis used a Pearson Chi-squared test or a one-sided Fisher's Exact test as appropriate. Suggested relationships were found between specific microorganisms, especially gram-negative anaerobes, and the presence of spontaneous or previous pain, tenderness to percussion, pain on palpation and swelling amoxicillin, amoxicillin + clavulanate and cephaclor were effective against all the strains tested. The lowest susceptibility rate was presented by Prevotella intermedia/nigrescens against Penicillin G. Our results suggested that specific bacteria are associated with endodontic symptoms of infected teeth with periapical periodontitis and the majority of the anaerobic bacterial species tested were susceptible to all antibiotics studied.     

牙髓炎及根尖周病患牙微生物的超微结构观察

目的扫描电镜观察牙髓炎和根尖周病患牙微生物的超微结构。方法收集健康牙（n=6）、不可复性牙髓炎（n=10）、牙髓坏死（n=20）、慢性根尖周炎（n=20）及难治性根尖周炎（n=6）病例共62例,分为2组,每组各31例,采用扫描电镜观察根管内牙本质面（A组）和根尖周牙骨质面（B组）的微生物形态和定植模式。结果①A组：3例健康牙根管内没有细菌存在;其余28例感染根管内均能观察到被胶状基质包裹的菌落构成生物膜,其中26例（92.9%）可见细菌不同程度侵入牙本质小管;2例难治性根尖周炎样本根管内发现真菌感染。②B组：健康组、不可复性牙髓炎组、牙髓坏死组（共18例）根尖仅见牙周膜胶原纤维网,无细菌生物膜结构;其余13例根尖周炎的患牙均出现根尖骨质吸收纤维破坏以及斑块状根尖生物膜;3例难治性根尖周炎超充牙胶尖表面亦覆盖细菌生物膜。生物膜的超微结构由于基质的多寡和细菌组成不同而表现各异。结论口腔微生物在牙髓炎和根尖周病患牙中主要以生物膜的方式定植,并可侵入牙本质小管或隐匿于牙骨质吸收腔隙中。     

Prevalence and clonal analysis of Porphyromonas gingivalis in primary endodontic infections

This study investigated the prevalence of Porphyromonas gingivalis in 62 teeth with primary endodontic infections by using a species-specific 16S rRNA gene-based nested polymerase chain reaction assay. P. gingivalis isolates recovered from 2 infected root canals were also analyzed for clonal diversity by using arbitrarily primed PCR. Overall, P. gingivalis was found in 48% of the samples. This species was specifically detected in 36% of canals of teeth with chronic apical periodontitis, in 46% of the cases of acute apical periodontitis, and in 67% of acute apical abscesses. P. gingivalis was significantly more frequent in abscess aspirates than in canals of teeth with chronic apical periodontitis (P < .05). Typing of colonies retrieved from 2 infected canals revealed 2 clones per individual. These findings confirmed that P. gingivalis can be an important endodontic pathogen, mostly associated with acute abscesses, and demonstrated that different clonal types of this species can colonize the root canal in the same individual.     

Isolation and classification of anaerobic bacteria from pulp cavities of nonvital teeth in man.

The anaerobic microflora of infected pulp cavities and chronic periapical abscesses was studied. A total of 19 infected nonvital teeth were subjected to this study. The coronal surface was swabbed with 70% ethanol to remove debris and to disinfect. Material in root canal chamber was obtained by sterilized paper points and suspended in reduced transport fluid. The samples were dispersed, diluted, and inoculated on blood agar plates. Isolates were identified by colony characteristics and cellular morphology, fermentation, indole production, nitrate reduction, gelatin digestion, urease production, ability to grow aerobically, API 20A System, and API ZYM System. Anaerobic bacteria were found in 14 pulp cavities. Anaerobic gram-negative rods, Actinomyces species, and Propionibacterium species were predominant in the root canals. Mixed infection with anaerobes and facultative anaerobes were demonstrated in most of the pulpal cavities of nonvital teeth.     

IL-17在乳牙根尖周病损组织中的表达

目的:检测IL-17在乳牙根尖周病损组织中的表达和分布,分析其在不同病理类型及炎症程度之间的关系,探讨其在乳牙慢性根尖周炎发病机制中的可能作用。方法:收集120例乳牙慢性根尖周病损组织行常规组织病理学检查,确定病理类型并按炎症细胞浸润程度分级;免疫组织化学法检测组织中IL-17的分布特点;ELISA法检测IL-17的蛋白表达量。结果:120例乳牙慢性根尖周病损组织中根尖周肉芽肿占65.8%,根尖周囊肿占18.4%,根尖周脓肿占15.8%。IL-17在3种病理类型中均有表达,主要表达于淋巴细胞、浆细胞。ELISA结果显示IL-17在不同病理类型组中的表达均低于正常对照组,在根尖肉芽肿组中的表达与炎症程度呈负相关。结论:IL-17在乳牙根尖周病损组织内广泛存在,随炎症程度加重表达逐渐降低,推测IL-17在乳牙慢性根尖周炎的病程进展中可能发挥一定的抑制作用。     

四种浓度次氯酸钠根管消毒效果的评价

目的 探讨4种浓度次氯酸钠对感染根管的消毒作用.方法 将100例慢性根尖周炎患者随机分为5组,分别使用0.25%、0.50%、1.00%、2.00%的次氯酸钠和生理盐水作为根管冲洗剂,根管预备前后,分离、培养根管内厌氧菌,观察并记录细菌形态及菌落数.结果 4种浓度次氯酸钠对感染根管均有消毒作用,生理盐水的根管消毒作用差.结论 在橡皮障未能普及的情况下,作为根管冲洗剂的次氯酸钠合适浓度为1.00%.