Significance of detection of Porphyromonas gingivalis, Bacteroides forsythus and Treponema denticola in periodontal pockets

The relationship between the detection of Porphyromonas gingivalis, Bacteroides forsythus and Treponema denticola in subgingival plaque samples of periodontal pockets and periodontal status was evaluated using the polymerase chain reaction (PCR). A total of 165 sites in 60 periodontitis patients were examined, and the relationships between the detection of each of the three bacterial species and the pocket depth and bleeding on probing (BOP) were analyzed. The detection ratios of P. gingivalis, B. forsythus, and T. denticola in samples from adult periodontitis lesions were 75.5%, 69.8%, and 72.6%, respectively. It was found that all sites where all three microorganisms were detected were BOP positive and had greater pocket depths than those where only one or two species were found. The detection rate of B. forsythus and T. denticola decreased with age in the sites in which PD was less than 4 mm. The present study indicates that detection of a mixed infection by P. gingivalis, B. forsythus, and T. denticola strongly correlated with adult periodontitis.     

不同引物检测慢性牙周炎龈下菌斑中齿垢密螺旋体

目的：利用两个不同引物对慢性牙周炎患者患病部位及相对健康部位龈下菌斑中齿垢密螺旋体（Td）进行检测,以了解Td在慢性牙周炎患者不同部位的分布及Td检出率与牙周炎临床指标的关系。方法：收集58例慢性牙周炎患者患病部位及相对健康部位龈下菌斑标本,利用PCR分别扩增53kDa外膜蛋白表达基因tdpA片段及16srRNA保守区片段。结果：58个患病部位龈下菌斑标本中tdpA及16srRNA扩增的阳性率分别为58．6％和81．0％,而相对健康部位龈下菌斑标本中PCR阳性率分别为8．62％及15．5％,患病部位Td检出率高于相对健康部位（P〈0．001）,16srRNA基因片段引物检出率高于tdpA基因片段（P〈0．05）。临床附着丧失≥5mm的患牙龈下菌斑标本中Td的检出率高于临床附着丧失〈5mm标本（P〈0．05）,不同牙周袋深度及牙龈指数标本的Td检出率之间差异无统计学意义（P〉0．05）。结论：在慢性牙周炎患者活动部位龈下菌斑中Td检出率高于相对健康部位;Td感染与慢性牙周炎关系密切;利用16srRNA保守区片段对齿垢密螺旋体进行检测检出率高于tdpA基因片段。     

5种牙周龈下可疑致病微生物与慢性牙周炎局部不同牙周状态间的关系

目的 观察5种龈下微生物检出水平与慢性牙周炎局部牙周状态的关系。方法 选择20例慢性牙周炎患者的80个位点及10例牙周健康者的20个位点为观察位点,采集龈下微生物样本,记录牙周探诊深度（PD）,根据所测位点的PD进行分组。PD≤4 mm为A组,4 mm＜PD≤6 mm为B组,PD>6 mm为C组,健康对照组为H组。通过聚合酶链反应（PCR）和DNA探针反杂交技术半定量检测各组伴放线菌嗜血菌、牙龈卟啉单胞菌、福赛斯坦纳菌、齿垢密螺旋体和中间普氏菌的检出率和检出水平。结果 B、C组牙龈卟啉单胞菌、福赛斯坦纳菌、齿垢密螺旋体和中间普氏菌的检出率和检出水平均高于H组,A组牙龈卟啉单胞菌的检出率和检出水平也高于H组,C组福赛斯坦纳菌和齿垢密螺旋体检出水平高于B组,以上差异均有统计学意义（P<0.05）;伴放线菌嗜血菌在各组间的检出率及检出水平都无明显差异。结论 随着牙周袋的加深,牙龈卟啉单胞菌、福赛斯坦纳菌、齿垢密螺旋体和中间普氏菌体的阳性检出率和检出水平都有随之增加的趋势;牙龈卟啉单胞菌与慢性牙周炎的早期炎症关系较为密切,而福赛斯坦纳菌和齿垢密螺旋体与中重度慢性牙周炎炎症位点的严重程度有关。     

慢性牙周炎龈下菌斑中五种牙周可疑致病微生物的分布

目的研究五种牙周可疑致病微生物在慢性牙周炎患者龈下菌斑的分布。方法选择27例慢性牙周炎患者,每位患者选取牙周袋最深的两个位点作为观察位点,采集龈下微生物样本,采用多重聚合酶链反应和反杂交的方法对伴放线菌嗜血菌、牙龈卟啉单胞菌、福赛斯坦纳菌、中间普雷沃菌和齿垢密螺旋体五种微生物进行半定量检测。结果在所检测的54个位点中,牙龈卟啉单胞菌、中间普雷沃菌、福赛斯坦纳菌和齿垢密螺旋体均有较高的检出率,分别为98.15%、92.59%、100%和98.15%;伴放线菌嗜血菌检出率较低,为20.37%。牙龈卟啉单胞菌和福赛斯坦纳菌的检出量明显高于其他三种微生物,其差异有统计学意义（P<0.05）。结论慢性牙周炎患者多存在牙龈卟啉单胞菌、福赛斯坦纳菌、中间普雷沃菌和齿垢密螺旋体的同时感染,且牙龈卟啉单胞菌和福赛斯坦纳菌的感染量较高。     

Treponema denticola and Porphyromonas gingivalis as prognostic markers following periodontal treatment.

Subgingival plaque samples were collected from individuals with advanced periodontitis before and 3 to 11 weeks after scaling and root planing periodontal treatment. The plaque levels of Treponema denticola and Porphyromonas gingivalis antigens were measured before and after treatment by a quantitative immunoassay procedure using monoclonal antibodies specific for these oral bacteria. A decrease in mean levels of T. denticola (P less than .05) and P. gingivalis antigens (P less than .09) were observed following periodontal therapy. Improved health, as measured by a decrease in probing depth, was associated with a decrease in T. denticola antigen (P less than .05). These results suggest that the T. denticola levels of successfully treated sites decreased, while non-responding sites had levels of this microbial marker which were equal to or greater than the pre-treatment levels. These results provide additional evidence that T. denticola is associated with human adult severe periodontal disease, and can serve as a prognostic marker for disease recurrence.     

Sulfate-reducing bacteria in relation with other potential periodontal pathogens

BACKGROUND, AIMS: Oral sulfate-reducing bacteria are involved in several clinical categories of periodontitis. The aim of this cross-sectional study was to compare the presence of sulfate-reducing bacteria (SRB) with other putative pathogens including spirochetes, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, and Treponema denticola in periodontal lesions. METHOD: Periodontal SRB were detected by enrichment culture and compared with a microscopic spirochete count (n=168). Species-specific oligonucleotide probes directed against the 16S rRNA were employed to determine the presence of A. actinomycetemcomitans, P. gingivalis, B. forsythus, and T. denticola (n=55). RESULTS: A significant positive correlation was observed between the presence of SRB and the proportions of spirochetes in subgingival plaque, although the 2 bacterial groups also occurred separately. SRB tended to be negatively correlated with the presence of A. actinomycetemcomitans. In contrast, all pockets with SRB harbored either T. denticola, or both T. denticola and B. forsythus (12/14) before therapy. Interestingly, the combination of SRB with P. gingivalis occurred in 32% of the periodontal pockets before treatment. After initial periodontal therapy, the prevalence of this combination was reduced to 2% of the sites, and to 25% of the sites in recall patients. CONCLUSION: The presence of SRB was positively correlated with T. denticola, B. forsythus, and P. gingivalis in periodontal lesions. These suspected pathogens form a complex strongly associated with destructive periodontitis.     

A sensitive enzymatic method (SK-013) for detection and quantification of specific periodontopathogens

Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola have been found to predominate in periodontal pockets of patients with adult periodontitis. These microorganisms hydrolyze the synthetic peptide N-benzoyl-DL-arginine-2-naphthylamide (BANA). In this study, we developed an enzymatic method, designated SK-013, to detect the existence of these microorganisms in subgingival plaque bacteria. This enzymatic method was based on the observation of the hydrolysis of N-carbobenzoxy-glycyl-glycyl-arginyl-3,5-dibromo-4-hydroxyaniline (N-CBz-Gly-Gly-Arg-DBHA) and made more sensitive by adding an enhancing system. The SK-013 was specifically positive for P. gingivalis, B. forsythus, T. denticola, and some strains of Capnocytophaga species, but was not specific for any of the other bacterial strains tested. This SK-013 system may be valuable for detection and quantification of periodontal disease-associated bacteria in subgingival plaque and thus for diagnosis of periodontal infections.     

Site-specific development of periodontal disease is associated with increased levels of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia in subgingival plaque

BACKGROUND: Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia (previously T. forsythensis), which are regarded as the principal periodontopathogenic bacteria, exist as a consortium in subgingival biofilms. We aimed to examine quantitative relationships between P. gingivalis, T. denticola, and T. forsythia in subgingival biofilms and the relationship between the quantity and prevalence of these three bacteria and site-specific periodontal health. METHODS: This study was cross-sectional. The study population consisted of 35 adult subjects who visited the Kyushu Dental College Hospital. Plaque samples were collected from 105 periodontal pocket sites. Quantitative analyses of each of the three periodontopathogenic bacteria were performed using real-time polymerase chain reaction with species-specific primers and hybridization probes. RESULTS: The plaque samples were divided into four groups based on the presence or absence of a periodontal pocket (probing depth [PD] > or =4 mm) and bleeding on probing (BOP), regardless of attachment loss. The proportions of all three target bacteria detected in samples from sites of periodontal disease (with PD and BOP) were markedly higher than those in the other sample groups. Cell numbers of P. gingivalis, T. denticola, and T. forsythia in the subgingival plaque of each sampling site were significantly mutually correlated and were increased in the plaque of sites of periodontal disease with PD > or =4 mm and BOP. CONCLUSION: The symbiotic effects of P. gingivalis, T. denticola, and T. forsythia, which coaggregate and exist concomitantly in subgingival biofilms, may be associated with the local development of periodontitis.     

慢性牙周炎栖牙密螺旋体和牙周袋内硫化物水平的相关性研究

目的 研究慢性牙周炎病人牙周袋内栖牙密螺旋体和牙周袋内硫化物水平的关系。方法 临床上选取17例诊断为慢性牙周炎的病人,采用金刚探针/牙周诊断仪检测牙周袋内硫化物水平,记录牙周袋探诊深度、临床附着丧失以及探诊出血相关牙周指标。同时,采用16S rRNA PCR检测相同位点的栖牙密螺旋体。结果 慢性牙周炎病人栖牙密螺旋体检出率为88.2%,硫化物阳性位点和硫化物阴性位点中栖牙密螺旋体的检出率分别为68.5%和43.2%。硫化物阳性位点与阴性位点中牙周附着丧失（clinical attachment loss, CAL）平均值分别为（2.84±2.33）mm和（1.83±1.60）mm,两者差异有统计学意义（P<0.01）。硫化物阳性位点与阴性位点牙周探诊深度（probing depth, PD）平均值分别为（4.20±1.57）mm和（3.83±1.30）mm,两者差异无统计学意义(P＞0.05)。硫化物阳性位点中牙周探诊出血（bleeding on probing, BOP）阳性检出为率92.5%,大于硫化物阴性位点（75.8%）,两者差异有统计学意义（P<0.01）。结论 慢性牙周炎病人牙周袋内的硫化物水平能反映牙周栖牙密螺旋体分布情况,与牙周附着丧失存在相关性。     

Microbiologic analysis of periodontal pockets and carotid atheromatous plaques in advanced chronic periodontitis patients

BACKGROUND: In recent years, many researchers have focused their attention on the ability of periodontal pathogens to colonize atheromatous plaques. Nevertheless, a clear correlation between the detection rates of periodontopathic bacterial DNA in atheromas and in subgingival plaque samples has not been established. The aim of our study was to assess the presence of five periodontal pathogens (Actinobacillus actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia [formerly Tannerella forsythensis]) in periodontal pockets and in carotid atheromas recovered from the same patients. METHODS: Thirty-three patients with advanced chronic periodontitis scheduled for endarterectomy were enrolled in the study. DNA was extracted from subgingival plaque samples and carotid atheromas. Universal bacteria primers for general detection of bacteria and species-specific primers for detection of periodontal pathogens were used to amplify part of the 16S rRNA gene by polymerase chain reaction. RESULTS: All subgingival plaque samples were positive for at least one target microorganism. The prevalence of T. forsythia, P. gingivalis, T. denticola, P. intermedia, and A. actinomycetemcomitans were 69.7%, 63.6%, 54.5%, 45.4%, and 33.3%, respectively. Bacterial DNA was detected in 31 out of 33 endarterectomy specimens. However, none of the samples tested positive for DNA from periodontal pathogens. CONCLUSION: The presence of periodontal bacteria in atheromatous plaques was not confirmed by this investigation; thus, no correlation could be drawn between periodontitis bacteria and microorganisms involved in the atherosclerotic lesions.     

Prevalence of periodontopathic bacteria in aggressive periodontitis patients in a Japanese population

BACKGROUND: Actinobacillus actinomycetemcomitans is considered a major etiologic agent of aggressive periodontitis. Other periodontopathic bacteria such as Porphyromonas gingivalis are also suspected of participating in aggressive periodontitis, although the evidence is controversial. The aim of the present study was to investigate the prevalence of periodontopathic bacteria and to clarify the microbiological features of aggressive periodontitis in Japanese patients. METHODS: Subgingival plaque was collected from 50 aggressive periodontitis (AgP) patients (localized 10, generalized 40). Samples from 35 generalized chronic periodontitis (CP) patients and 18 healthy subjects were examined as controls. Plaque samples were examined using culture and polymerase chain reaction (PCR) method. RESULTS: The prevalence of A. actinomycetemcomitans was relatively low in the localized (20%) and generalized (17.5%) AgP patients, with no significant difference observed in detection frequencies between AgP and the control groups (CP 8.6%, healthy 0%). On the other hand, Tannerella forsythensis (formerly Bacteroides forsythus), Campylobacter rectus, P. gingivalis, and Treponema denticola were frequently detected in localized as well as generalized aggressive periodontitis patients. The prevalence and proportion of P. gingivalis correlated with severity of clinical attachment loss in both localized and generalized aggressive periodontitis. CONCLUSIONS: T. forsythensis, C. rectus, P. gingivalis, and T. denticola were the predominant periodontopathic bacteria of aggressive periodontitis patients in Japan. Although A. actinomycetem- comitans was also detected in AgP patients, the prevalence of this bacterium was much lower than that of P. gingivalis.     

Associations between Porphyromonas gingivalis and oral treponemes in subgingival plaque

Colonization and/or proliferation of Treponema denticola may depend on the presence of Porphyromonas gingivalis . The aims of this study were to confirm this synergistic relationship, to determine whether other oral bacteria were similarly associated with P. gingivalis and to relate coinfection to the periodontal status of plaque donors. Subgingival plaque was collected from every tooth except third molars in 106 subjects who were grouped by their worst periodontal condition. In addition to P. gingivalis , monoclonal antibodies were used to identify Campylobacter rectus, Eikenella corrodens, T. denticola, Treponema socranskii and pathogen-related oral spirochetes. Associations of these bacteria with coinfection by P. gingivalis were assessed by estimated odds ratios. The results indicate that coinfection with P. gingivalis is linked to all tested bacteria, but each pair was associated with distinct periodontal conditions. The distribution of coinfected sites suggests biased colonization of facial surfaces over lingual surfaces.     

Prostaglandin E(2) is a main mediator in receptor activator of nuclear factor-kappaB ligand-dependent osteoclastogenesis induced by Porphyromonas gingivalis, Treponema denticola, and Treponema socranskii

BACKGROUND: Periodontitis is an inflammatory disease that often leads to destruction of alveolar bone; a number of bacteria in subgingival plaque are associated with bone destruction in periodontitis. To understand the mechanism of how periodontopathogens induce osteoclastogenesis, we determined which mediators are involved in the osteoclastogenesis. METHODS: We investigated effects of sonicates from three periodontopathic bacteria, Porphyromonas gingivalis, Treponema denticola, and Treponema socranskii, on osteoclast formation in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. The osteoclast formation was determined by tartrate resistant acid phosphatase (TRAP) staining. The expression of the receptor activator of nuclear factor-kappa B ligand (RANKL), prostaglandin E(2) (PGE(2)) and osteoprotegerin (OPG) in mouse calvaria-derived osteoblasts was determined by immunoassay. RESULTS: Each bacterial sonicate induced the osteoclast formation in the co-culture system. These bacterial sonicates increased the expression of RANKL and PGE(2), and decreased the expression of OPG in osteoblasts. The addition of OPG, an inhibitor of RANKL, in the co-culture completely suppressed the osteoclastogenesis that was stimulated by each bacterial sonicate. Indomethacin, which is an inhibitor of PGE(2) synthesis, reduced more than 88% of the osteoclast formation induced by each bacterial sonicate. Indomethacin inhibited more than 80% of RANKL expression in osteoblasts induced by T. denticola and T. socranskii, and 59% by P. gingivalis. Indomethacin completely recovered the depression of OPG expression in osteoblasts by T. denticola and T. socranskii to the level of the untreated osteoblasts. Indomethacin recovered the reduction of OPG expression by P. gingivalis to 67%. CONCLUSION: These findings suggest that the osteoclastogenesis by P. gingivalis, T. denticola, and T. socranskii is mediated by a RANKL-dependent pathway and that PGE(2) is a main factor in the pathway by the enhancing of RANKL expression and the depression of osteoprotegerin, a RANKL inhibitor.     

Benzoyl-arginine naphthylamide (BANA) hydrolysis by Treponema denticola and/or Bacteroides gingivalis in periodontal plaques

Treponema denticola and Bacteroides gingivalis are among the few recognized species found in periodontal pockets that can hydrolyze the synthetic peptide N-benzoyl-DL-arginine-2-naphthylamide (BANA). We determined the presence of these periodontal pathogens in BANA-positive and -negative plaque samples through the use of indirect immunofluorescent antibody techniques. Eighteen of 27 diseased sites gave BANA-positive reactions, and 9 gave BANA-negative reactions. T. denticola was present in 16 of 18 BANA-positive reactions, whereas B. gingivalis was detected in 9 of the 18 BANA-positive reactions. T. denticola was present in 1 and B. gingivalis in 2 of the 9 BANA-negative reactions. Neither organism was detected in the 19 healthy sites that were negative for BANA. All measured differences between BANA-positive and BANA-negative plaques obtained in the same individuals were statistically significant. The accuracy of the BANA test, compared with clinical parameters such as bleeding upon probing and increased probing depth, was about 80%. The accuracy of the test in detecting the presence of T. denticola was 93%, for B. gingivalis, 76% and for T. denticola and/or B. gingivalis, 96%. This study indicated that BANA-positive plaques were associated with the presence of T. denticola and/or B. gingivalis, that T. denticola was found at a greater frequency and levels in BANA-positive plaques than B. gingivalis, and that the presence of these organisms was associated with clinical disease.     

侵袭性牙周炎病原微生物的检测

目的检测侵袭性牙周炎（AgP）患者和牙周健康者龈下菌斑中的7种病原微生物,旨在寻找AgP的主要致病微生物.方法应用以16S rRNA为基础的聚合酶链反应（PCR）技术,检测55例AgP患者和17名健康对照者龈下菌斑中的7种牙周病原微生物：伴放线放线杆菌（Aa）,牙龈卟啉单胞菌（Pg）,福赛坦氏菌（Tf）,牙密螺旋体（Td）,直肠弯曲杆菌（Cr）,中间普氏菌（Pi）,变黑普氏菌（Pn）.结果55例AgP患者中仅有1例检测出Aa,而在健康对照者中未检出该菌.Pg、Tf、Td和Cr在AgP组的检出率分别为81.8%、83.6%、80.0%和81.8%,显著高于健康对照者（17.6%、11.8%、5.9%、29.4%）,差异有统计学意义（P＜0.01）.结论Pd、Tf、Td和Cr 4种微生物在AgP患者中有较高的检出率,提示它们的共同定植可能在AgP中起重要作用.     

Prevalence of fimA genotypes of Porphyromonas gingivalis and other periodontal bacteria in a Spanish population with chronic periodontitis

Objectives: The aim of this study was to determine the prevalence of the different fimA genotypes of Porphyromonas gingivalis in adult Spanish patients with chronic periodontitis, patients with gingivitis and periodontally healthy subjects, and the relationship between these genotypes and other periodontopathogenic bacteria. Study design: Samples of subgingival plaque were taken from 86 patients (33 with chronic periodontitis, 16 with gingivitis, and 37 periodontally healthy) in the course of a full periodontal examination. PCR was employed to determine the presence of the 6 fimA genotypes of Porphyromonas gingivalis (I-V and Ib) and of Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola. Results: Porphyromonas gingivalis fimA genotypes II and Ib were present in significantly higher percentages in periodontal patients (39.4% and 12.1% respectively) than in healthy or gingivitis subjects. The prevalence of Tannerella forsythia, Treponema denticola, and Porphyromonas gingivalis fimA genotype IV was significantly higher in the group that presented bleeding greater than 30%. A positive correlation was found between Porphyromonas gingivalis fimA genotype IV and Treponema denticola. Conclusions: A strong association between Porphyromonas gingivalis fimA genotypes II and Ib and chronic periodontitis exists in the Spanish population. The most prevalent genotype in periodontal patients is II. Key words:Periodontitis, Porphyromonas gingivalis, fimA genotype, periodontal bacteria, polymerase chain reaction.     

Relative proportions of pathogen-related oral spirochetes (PROS) and Treponema denticola in supragingival and subgingival plaque from patients with periodontitis.

The purpose of this study was to use monoclonal antibodies to enumerate spirochetes in dental plaque, including the newly recognized pathogen-related oral spirochete (PROS) and specific serovars of Treponema denticola. Plaque was collected from control subjects with no apparent periodontal disease and from sites of moderate to severe chronic periodontitis in patients with inflammatory periodontal disease. Individual monoclonal antibodies were used to determine whether spirochetes were present and then a double-staining protocol was employed to count total spirochetes and specific treponemes in individual microscopic fields. Results indicate that spirochetes are more common at diseased sites and in subgingival plaque than at healthy sites or in supragingival plaque. Together PROS and T. denticola comprised the majority of all spirochetes in all samples and PROS and T. denticola serovars "B" and D were most numerous in plaque from patients with periodontitis. PROS were the majority of all spirochetes in supragingival plaque (76.2% +/- 23.8%) and subgingival plaque (60.9% +/- 19.1%) from periodontitis patients, significantly larger than the percentage of T. denticola serovar "B" (P less than .001 for both supragingival and subgingival plaque) and serovar D (P less than .01 for supragingival and P less than .001 for subgingival plaque). These observations indicate that PROS are the predominant spirochete in plaque from sites of patients with periodontitis, but other analytical approaches are necessary to determine if PROS or T. denticola are pathogenic.     

Progression of chronic periodontitis can be predicted by the levels of Porphyromonas gingivalis and Treponema denticola in subgingival plaque

Introduction:  Chronic periodontitis is an inflammatory disease of the supporting tissues of the teeth associated with bacteria. Diagnosis is achieved retrospectively by clinical observation of attachment loss. Predicting disease progression would allow for targeted preventive therapy. The aim of this study was to monitor disease progression in patients on a maintenance program and determine the levels of specific bacteria in subgingival plaque samples and then examine the ability of the clinical parameters of disease and levels of specific bacteria in the plaque samples to predict disease progression.
Methods:  During a 12-month longitudinal study of 41 subjects, 25 sites in 21 subjects experienced disease progression indicated by at least 2 mm of clinical attachment loss. Real-time polymerase chain reaction was used to determine the levels of Porphyromonas gingivalis , Treponema denticola , Tannerella forsythia , Fusobacterium nucleatum , and Prevotella intermedia in subgingival plaque samples.
Results:  No clinical parameters were able to predict periodontal disease progression. In sites undergoing imminent periodontal disease progression within the next 3 months, significant partial correlations were found between P. gingivalis and T. forsythia ( r  = 0.55, P  < 0.001) and T. denticola and T. forsythia ( r  = 0.43, P  = 0.04). The odds of a site undergoing imminent periodontal disease progression increased with increasing levels of P. gingivalis and T. denticola .
Conclusion:  Monitoring the proportions of P. gingivalis and T. denticola in subgingival plaque has the potential to help identify sites at significant risk for progression of periodontitis, which would assist in the targeted treatment of disease.     

Bacterial synergy of Treponema denticola and Porphyromonas gingivalis in a multinational population

Treponema denticola and Porphyromonas gingivalis have been associated with human adult severe periodontitis. In this study, we quantified these putative pathogens in subgingival plaque samples collected from 74 Fijians, 74 Colombians and 73 U.S. Americans stationed at the Multinational Force and Observers encampment in the Sinai Desert, Egypt. A contingency table of T. denticola and P. gingivalis frequency revealed a highly significant synergistic relationship. We discovered that the occurrence of T. denticola apparently requires the presence of P. gingivalis. This represents the first observation of a synergistic relationship between these putative oral pathogens associated with adult severe periodontal disease.     

Detection of putative periodontal pathogens in non-insulin-dependent diabetes mellitus and non-diabetes mellitus by polymerase chain reaction

It has been assumed that there is a relationship between periodontal diseases and diabetes mellitus, however the putative periodontal microorganisms in non-diabetes mellitus (non-DM) individuals and non-insulin-dependent diabetes mellitus (NIDDM) patients have not been well studied. In this study, the detection rates of 5 putative periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Eikenella corrodens, Treponema denticola, and Candida albicans by polymerase chain reaction (PCR) between NIDDM and non-DM adults were compared. A total of 246 adults were randomly recruited and periodontal parameters including: plaque index (P1I), gingival index (GI), probing depth (PD) and attachment level (AL) were recorded. Subgingival plaque samples were collected by sterile curettes from the most diseased and healthy sites based on PD and AL. The differences in periodontal parameters and microbiological data in healthy and diseased sites between non-DM and NIDDM patients were compared by chi-square analysis. The results showed no significant differences in age, gender, GI, P1I, PD, and prevalence of the 5 microorganisms between the NIDDM and the non-diabetic groups. However, except for A. actinomycetemcomitans, the prevalence of the periodontal microorganisms tested was significantly higher (p <0.001) in diseased sites than in the healthy sites in both groups. The P1I, GI, PD and AL were significantly higher in T. denticola positive sites than in negative sites. The results suggested that P. gingivalis, T. denticola, E. corrodens and C. albicans may play important roles in the periodontitis of both NIDDM and non-DM individuals, however the etiology of periodontitis in both groups may not be different from each other.