Actinobacillus actinomycetemcomitans recovery from extracrevicular locations of the mouth

Associations between recovery of Actinobacillus actinomycetemcomitans from samples of subgingival plaque, and samples of buccal mucosa, tongue and unstimulated saliva were studied in 107 subjects. Ten subjects had gingivitis, 18 localized juvenile periodontitis, 45 rapidly progressive periodontitis and 32 adult periodontitis. Two children suffered from prepubertal periodontitis. Heterogeneity tests for associations in different study populations yielded nonsignificant results. Mantel-Haenszel's common odds ratios were 52.9, 37.2 and 19.8 for respective associations between pooled subgingival samples, and cheek, saliva and tongue samples. Significant McNemar's chi-square of 5.88, 11.25 and 16.96 for respective associations pointed to secondary occurrence of A. actinomycetemcomitans in extra-crevicular samples. Multiple linear regression yielded a significant influence of the number of deep periodontal pockets of 7 mm or more and a negative influence of the diagnosis "adult periodontitis" on the log-transformed number of colony-forming units of A. actinomycetemcomitans in samples from cheek mucosa in patients infected with the organism. Extracrevicular occurrence of A. actinomycetemcomitans seems to reflect total subgingival numbers of the organism. Especially sampling check mucosa appears to be a promising tool in the diagnosis of a periodontal infection with A. actinomycetemcomitans .     

Natural distribution of oral Actinobacillus actinomycetemcomitans in young men with minimal periodontal disease

A total of 1005 subgingival and extracrevicular samples from 201 male recruits, 18–25 yr old, were selectively cultivated for Actinobacillus actinomycetemcomitans. The organism was isolated in 55 subjects (27%); 9.5% of pooled subgingival plaque samples from first molars, 14% cheek mucosa, 20% dorsum of tongue and 20% saliva samples were culture-positive. In order to divide the study population into distinct clinical categories, cluster analysis was performed, based on previous caries experience, probing pocket depth categories, bleeding scores, visible plaque and calculus. Two clusters (n=86 and n=92, respectively) were identified with no or minimal periodontal disease (mean±standard deviation % of periodontal probing depth 1–2 mm 78.7±10.4% and 57.4±12.6%, respectively; virtually no periodontal probing/depth in excess of 4 mm) and a relatively low DMF-S (22±13). A third cluster (n=22) had, in contrast, a high DMF-S (47.7±173) and a relatively high % of periodontal pockets of ≥5 mm (5.9 ±5.2%). Prevalence of A. actinomycetemcomitans in this cluster was 41%, while the organism was found in 23% and 27% in the minimally diseased populations (p<0.15). Whereas no heterogeneity of associations between subgingival and extracrevicular occurrence of the organism could be ascertained in different clusters, the organism was significantly more often identified in extracrevicular material, especially dorsum of tongue samples, compared with subgingival plaque (McNemar's X²=12.45, p<0.001). Multiple linear regression analysis revealed the number of A. actino-mycetemcomitans positive samples as well as the % of sites bleeding on probing being positively associated with the % of sites with a probing pocket depth of ≥5 mm (R2=0.345, p≤0.0001). The present large-scale investigation points to the wide distribution of this putative periodontopathogen in young individuals with minimal periodontal disease.     

Eradication of Actinobacillus actinomycetemcomitans from the oral cavity in adult periodontitis

Eradication of Actinobacillus actinomycetemcomitans from the oral cavity seems to be a prerequisite for successful therapeutic outcome in patients periodontally infected with the organism. In view of the limited number of subgingival samples obtained in recent studies one cannot conclude, however, whether eradication has actually been achieved. In the present study clinical and microbiological parameters were monitored in 10 adult patients with A. actinomycetemcomitans-associated periodontitis during successive non-surgical and adjunctive metronidazole plus amoxicillin (or ciprofloxacin) (AB) therapy. In every patient, 13 extracrevicular samples and subgingival samples from the deepest site of every tooth present were selectively cultivated for A. actinomycetemcomitans. The organism was isolated in 47 ± 29% subgingival and 64 ± 31% extracrevicular samples. Six weeks following subgingival scaling, A. actinomyceterncomitans was detected in 37 ± 30% subgingival and 55 ± 38% extracrevicular samples (n.s.). Three months after antibiotic therapy, the organism was recovered from only 1 patient. At baseline, 7.5 ± 4.2% sites had a probing pocket depth (PPD) ≥7 mm. This proportion dropped to 2.3 ± 2.4% after scaling (p<0.05) and to 0.3 ± 0.4% after AB (p<0.05). The proportion of sites with clinical attachment loss (CAL) ≥6 mm dropped from 23.3 ± 13.3% to 17.7 ± 13.4% (p<0.05) and to 16.8 ± 14.6%. Statistical analysis revealed that the organism was strongly related, at baseline, to PPD ≥7 mm (odds ratio 9.8, p<0.001). Six weeks after scaling, the organism was associated with CAL ≥6mm (odds ratio 1.8, p = 0.02). After scaling, high counts of A. actinomycetemcomitans in excess of 10⁴ CFU/ml significantly interfered with attachment gain of ≥2 mm (odds ratio 0.24, p = 0.001). Based on the present findings, eradication of A. actinomycetemcomitans seems to be possible with adjunctive antibiotic treatment. Elimination of the organism after scaling was only weakly associated with clinical improvement.     

Microbial ecology of Actinobacillus actinomycetemcomitans, Eikenella corrodens and Capnocytophaga spp. in adult periodontitis

Information on intraoral distribution of putative periodontal pathogens might be essential for controlling different forms of periodontal disease. Colonization may be either promoted or impeded by other bacteria competing in the subgingival ecosystem. In recent investigations microbial associations between dental organisms have been determined in a multitude of subgingival plaque samples within multiple patients and described by odds ratios, in most circumstances without taking into account the correlated structure of the observations within a single individual. The present investigation had 3 major objectives: (i) to describe the intraoral distribution of some facultatively anaerobic, Gram-negative rods, i.e. Actinobacillus actinomycetemcomitans, Eikenella corrodens-like organisms and Capnocytophaga spp., in a multitude of subgingival and extracrevicular samples of 10 adult subjects with A. actinomycetemcomitans-associated periodontitis; (ii) to analyse possible inconsistencies of microbial associations between these periodontal organisms; and (iii) to determine factors increasing the likelihood of isolating these bacteria in a given subgingival site by employing Generalized Estimation Equation (GEE) methods. Clinical examinations were carried out at 6 sites of every tooth present. In each subject, 13 extracrevicular (2 cheek mucosa, 3 tongue, 4 gingival, 2 tonsillar samples, 1 palatinal, 1 saliva sample) and between 22 and 44 subgingival samples from deepest sites of every tooth present (n=296) were selectively cultivated for A. actinomycetemcomitans, E. corrodens and Capnocytophaga spp. In extracrevicular material, A. actinomycetemcomitans, Capnocytophaga spp. and E. corrodens were isolated in 9, 10 and 6 patients, and from 65, 82 and 15% samples, respectively. The organisms were recovered from 51, 62 and 27% subgingival plaque samples, respectively. Heterogeneity tests did not reveal significant inconsistencies of microbial associations between bacteria in subgingival plaque. Mantel-Haenszel's odds ratios ranged between 2.0 for A. actinomycetemcomitans and Capnocytophaga spp. and 18.7 for Capnocytophaga spp. and E. corrodens. An exchangeable working dependence structure was employed in the GEE approach. The odds of isolating A. actinomycetemcomitans was increased by factor 3.7 in 4–6 mm deep pockets, and 9.5 in ≥ 7 mm deep pockets. The odds of presence of E. corrodens was increased by factor 10.8 in the case of presence of Capnocytophaga spp. and 2.1 in the case of presence of A. actinomycetemcomitans. Capnocytophaga spp. were associated with bleeding on probing and molar sites. Presence of E. corrodens was associated with clinical attachment loss but not periodontal probing depth. Results of the present study indicated an association of A. actinomycetemcoinitans with periodontal pathology. Whereas this organism and Capizocytopliagae were widely distributed in extracrevicular ecosystems of the mouth, E. corrodens only occasionally appeared in saliva or on mucous membranes of the oral cavity. In general, GEE methods seem to allow to determine factors associated with the presence of periodontal organisms in a multivariate approach and considering the correlated structure of the data.     

Multilevel modeling of gingival bleeding on probing in young adult carriers of non-JP2-like strains of Aggregatibacter actinomycetemcomitans

The influence of Aggregatibacter actinomycetemcomitans on inflammation in subjects with gingivitis has not been studied in great detail. Seventeen healthy young adults with plaque-induced gingivitis or localized mild chronic periodontitis harboring cultivable numbers of A. actinomycetemcomitans were thoroughly examined. Samples of subgingival plaque were obtained from mesial surfaces of all teeth present. In addition, 12 oral mucosal surfaces and unstimulated saliva were sampled. Species identity, presence of the leukotoxin gene, and absence of a specific 530 b deletion in the leukotoxin promoter region indicating non-JP2-like strains were assessed by polymerase chain reaction. Based on a multilevel random intercept model adjusted for probing depth, age, and smoking status, the odds of bleeding on probing was increased by a factor of 1.89 (1.09–3.29, p = 0.024) if, in addition to plaque, A. actinomycetemcomitans could be recovered from the site. At a site without visible supragingival plaque but with cultivable numbers of subgingival A. actinomycetemcomitans the odds ratio of bleeding on probing was 3.37 (0.86–13.2, p = 0.081). Simulating variance partition coefficients revealed that between 1–2% (a clean, shallow site without A. actinomycetemcomitans; a deep site covered by plaque containing A. actinomycetemcomitans) and 6–7% (a moderately deep site with neither visible plaque nor cultivable A. actinomycetemcomitans) of the residual variance was attributable to differences between subjects. The present cross-sectional study indicates that non-JP2-like strains of A. actinomycetemcomitans may enhance gingival bleeding tendency even in the absence of clinically visible supragingival plaque.     

Potential diagnostic value of sampling oral mucosal surfaces for Actinobacillus actinomycetemcomitans in young adults*

Actinobacillus actinomycetemcomitans has been implicated in the pathogenesis of several forms of early onset and refractory adult periodontitis. Early diagnosis of colonization of the oral cavity might be of importance in order to initiate preventive measures. The aim of the present study was to determine the potential diagnostic value of oral mucosal and salivary tests to identify, among healthy young men with no or minor periodontal disease, individuals colonized by A. actinomycetemcomitans. Two hundred and one male recruits. 18–25 yr of age, took part in the present study. Mean values of periodontal parameters suggested only minor periodontal disease. Of the sites, 64.8±17.6% (mean ± SD) had a periodonta) probing depth (PPD) of 1 or 2 mm. only 1.6±2.9% deep sites of 5 mm were detected. More than 1000 subgingival and extracrevicular samples were selectively cultivated for A. actinomycetemcomitans. The organism was isolated in 55 subjects (21%). The odds for presence of at least 1 deep site of 5 mm was increased by a factor 1.99 if A. actinomycetemcomitans could be recovered. In identifying subjects colonized by A. actinomycetemcomitans. diagnostic test parameters sensitivity and predictive value for a negative test were 74.5±5.9% and 91.1±2.3%', respectively, for both saliva and dorsum of tongue samples. In contrast, pooled subgingival plaque from mesial surfaces of 1st molars was only 34.5±6.4% sensitive: the negative predictive value was 80.2±3.0%. The results point to a high diagnostic value of oral mucosal and especially saliva samples to identify young adult individuals colonized by A. actinomycetemcomitans.     

Clinical effects of scaling and root planing in adults infected with<Emphasis Type="Italic"> Actinobacillus actinomycetemcomitans</Emphasis>

The periodontal pathogen Actinobacillus actinomycetemcomitans can frequently be isolated from subgingival plaque of adults with chronic inflammatory periodontal disease and individuals with plaque-induced gingivitis. Problems with the persistence of the organism after thorough debridement of root surfaces have been reported. In the present study clinical effects of the hygienic phase of periodontal therapy in ten adult patients with moderate or advanced periodontitis harbouring A. actinomycetemcomitans were analysed. Since proper analysis of highly correlated data within a given patient is crucial for appropriate interpretation, a major objective of this study was to compare the results of different models derived from logistic regression of clinical and microbiological factors on gain or loss of clinical attachment under different assumptions. Subgingival samples from every tooth present were obtained before and 6 weeks after thorough subgingival scaling, and selectively cultivated for the organism. A relevant gain of clinical attachment of 2 mm or more was observed at a total of 36% of periodontitis sites after scaling. Overall, loss of attachment of 2 mm or more was observed at 8% sites. Most loss occurred at sites with gingival enlargement (15%), whereas 3% periodontitis sites lost 2 mm or more. In multivariate analyses erroneously assuming either independence of data or correctly considering the correlated structure of observations attachment gain was mainly associated with deep probing depths at the outset. Presence or absence of A. actinomycetemcomitans before or after therapy was not included into the periodontitis models. Also, loss of attachment of 2 mm or more after subgingival scaling was not influenced by the organism. A direct comparison of the results obtained with both approaches of logistic regression may be helpful in the assessment of the influence of the magnitude of correlation of the data on the regression coefficients.     

Prevalence of Aggregatibacter actinomycetemcomitans in Sudanese patients with aggressive periodontitis: a case-control study

Elamin A, Albandar JM, Poulsen K, Ali RW, Bakken V. Prevalence ofAggregatibacter actinomycetemcomitansin Sudanese patients with aggressive periodontitis: a case–control study. J Periodont Res 2011; 46: 285–291.©2011 John Wiley & Sons A/S Background and Objective: Aggregatibacter actinomycetemcomitans is considered a possible etiological agent for aggressive periodontitis. The aim of this study was to determine the prevalence of the JP2 clone and non‐JP2 genotypes of A. actinomycetemcomitans in the subgingival plaque of patients with aggressive periodontitis and controls among Sudanese high‐school students. Material and Methods: In a previous study we examined a large representative sample of students attending high schools in Khartoum, Sudan. In this population, 17 patients with aggressive periodontitis and 17 controls (14–19 years of age) consented to participate in the present study. The subjects underwent a clinical periodontal examination, and subgingival dental plaque samples were collected using paper points. The presence of the A. actinomycetemcomitans JP2 clone and non‐JP2 genotypes were assessed using loop‐mediated isothermal amplification (LAMP) and the PCR. Results: The JP2 clone of A. actinomycetemcomitans was not detected in the subgingival plaque of either the cases or the controls. Non‐JP2 types of A. actinomycetemcomitans were detected in the subgingival plaque of 12 (70.6%) patients with aggressive periodontitis and from only one (5.9%) control subject, showing a significantly higher frequency of detection in cases than in controls (p = 0.0001). The odds ratio for the detection of A. actinomycetemcomitans in the subgingival plaque of the patients with aggressive periodontitis was 38.4 (95% confidence interval: 4.0–373.0; p = 0.002). The PCR and LAMP methods showed identical results pertaining to the identification of non‐JP2 types of A. actinomycetemcomitans. Conclusions: The JP2 clone of A. actinomycetemcomitans was not detected in the subgingival plaque of high school subjects in Sudan. The detection of non‐JP2 types of A. actinomycetemcomitans may be a useful marker of increased risk for development of aggressive periodontitis in young subjects.     

Failure of adjunctive minocycline-HCI to eliminate oral Actinobacillus actinomycetemcomitans

Abstract Considerable problems have been reported in the eradication of Actinobacillus actinomycetemcomitans from periodontal sites. The present communication describes the 2-year results of a comprehensive combined mechanical/surgical and adjunctive rainocycline (200 mg/day for 3 and another 2 weeks) treatment regimen in 28 patients with A. actinomycetemcomitans-associated periodontitis. Elimination of A. actinomycetemcomitans at periodontal sites was a prerequisite for gain of clinical attachment of ≥2 mm or decrease of probing depth to ≥4 mm after subgingival scaling plus minocycline (p<0.01). Whereas 2 years after active treatment A. actinomycetemcomitans could not be detected at monitored sites in 23 patients, the organism was found on buccal mucosa and in saliva in 17 and 12 cases, respectively. One or 2 years after periodontal surgery, there was a significant association between log₁₀-numbers of A. actinomycetemcomitans in buccal samples and numbers of residual pockets of ≥7 mm as well as gingival sites with overt gingivitis (R²= 0.687, p<0.001). Present results indicate failure of an even prolonged administration of adjunctive minocycline to eliminate oral A. actinomycetemcomitans in most cases of A. actmomycetemcomitans-associated periodontitis.     

Microbial Analysis of Subgingival Plaque Samples Compared to That of Whole Saliva in Patients With Periodontitis

Background: The detection of special bacterial species in patients with periodontitis is considered to be useful for clinical diagnosis and treatment. The collection of subgingival plaque samples is the common way for the determination of periodontopathic bacteria. However, recently, salivary analysis has been discussed as an advantageous future diagnostic method for periodontitis because it offers simple quantitative sampling and the possibility to assess various bacteria. The aim of this cross‐sectional study is to investigate whether there is a correlation between the results of different bacterial species in saliva and subgingival plaque samples from individuals with aggressive periodontitis (AgP) and chronic periodontitis (CP). Methods: Whole saliva and subgingival plaque samples from the deepest pocket of each quadrant were collected from 43 patients with CP and 33 patients with AgP. Twenty different bacterial species from both samplings were determined by the 16S ribosomal RNA‐based polymerase chain reaction with microarray technique. Results: All bacterial species were detected in salivary and subgingival plaque samples. For Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, as well as Actinomyces viscosus, Campylobacter rectus/showae, Prevotella intermedia, Parvimonas micra, Eubacterium nodatum, and Campylobacter gracilis, a significant positive correlation between salivary and subgingival plaque samples was detected in patients with both types of periodontitis. There were no significant differences in bacteria in salivary and subgingival plaque samples between AgP and CP. Conclusion: Salivary analysis might be discussed as a potential alternative to subgingival plaque sampling for microbiologic analysis in both AgP and CP.     

Intraoral distribution of Actinobacillus actinomycetemcomitans in young adults with minimal periodontal disease

The aim of the present study was to investigate the intraoral distribution of Actinobacillus actinomycetemcomitans in young adults with minor signs of periodontal disease but harboring the organisms in the oral cavity. 17 healthy volunteers, 20 to 27 years of age, participated. Samples from mucosal surfaces of the oro-pharyngeal cavity and saliva (n = 221) as well as subgingival plaque from every tooth (n =477) were selectively cultivated for A. actinomycetemcomitans. Species identity and presence of the leukotoxin encoding gene, ltxA, were checked by multiplex polymerase chain reaction. Moreover, the leukotoxin promoter region was analyzed. No isolate harbored a 530 bp deletion in the promoter region of the leukotoxin gene, signaling minimally toxic strains. 42.1 +/- 30.4% extracrevicular and 34.4 +/- 29.5% subgingival samples were culture-positive. In extracrevicular samples, the organism could easily be recovered from cheek mucosa (62%), saliva (59%) and the palatal tonsils (41%). Mean log-transformed numbers of A. actinomycetecomitans colony forming units (CFU/ml) in culture-positive material ranged between 1.8 from the hard palate and 2.3 from 10 microl saliva. The highest prevalence in subgingival plaque was observed at maxillary 3rd molars (55%) followed by maxillary lateral incisors (50%) and mandibular 3rd molars (41%). Mean log-transformed counts of CFU/ml ranged between 2.2 at maxillary 3rd molars and 3.4 at upper central incisors. When adjusted for jaw, site and tooth type, the odds of isolating higher numbers of the organism were increased with every mm probing depth by a factor of 1.35 (p <0.05). The odds ratio for bleeding on probing was 1.38. Thus, in this young adult population with minor periodontal disease, A. actinomyetemcomitans was mainly associated with some deviation from gingival health. Of concern might be a minority of subjects (29%) with an extremely wide distribution of the organism in the oral cavity.     

Subgingival Microbiota in White Patients With Desquamative Gingivitis: A Cross‐Sectional Study

Background: Presence of epithelial desquamation, erythema, and erosions on gingival tissue is usually described in the literature as desquamative gingivitis (DG). A wide range of autoimmune/dermatologic disorders can manifest as DG, although the two more common are oral lichen planus and mucous membrane pemphigoid. The aim of this study is to investigate prevalence of 11 periodontopathogenic microorganisms in patients with DG and to compare it with the microbiologic status of individuals affected by plaque‐induced gingivitis (pGI). Methods: Cross‐sectional clinical and microbiologic data were obtained from 66 patients (33 in each group). Subgingival plaque samples were analyzed using semiquantitative polymerase chain reaction analysis. Results: Statistically significant difference, but with little clinical significance, was observed in gingival conditions between the two groups, probably due to the worse home control hygiene of patients with DG. Prevalence and levels of Aggregatibacter actinomycetemcomitans, Eikenella corrodens, and Fusobacterium nucleatum/periodonticum were statistically higher in samples from patients with DG than in those with pGI. In multivariate regression models, subgingival colonization of A. actinomycetemcomitans and F. nucleatum/periodonticum was not statistically associated with DG, whereas, high levels of E. corrodens were associated with 13‐fold increased odds for DG. Conclusions: Microbiologic differences were found in subgingival plaque for patients with DG and pGI. This may suggest possible association between periodontal pathogens and DG.     

Detection of Actinobacillus actinomycetemcomitans in unstimulated saliva of patients with chronic periodontitis

BACKGROUND: The use of whole saliva has shown to be promising in detecting Actinobacillus actinomycetemcomitans out of the subgingival environment. The objective of the present study was to evaluate the use of unstimulated saliva in detecting A. actinomycetemcomitans and to compare the subgingival and extracrevicular occurrence of this pathogen in Brazilian subjects with chronic periodontitis. METHODS: Sixty-six patients (mean age 38.01 9.28 years) with advanced generalized chronic periodontitis were sampled. Subgingival plaque samples were collected from eight sites per patient representing the two deepest sites of each quadrant. Samples of the mucous surfaces, including dorsal surface of the tongue and cheek, were collected with a sterile swab and placed in a microtube containing a reduced solution. Samples of unstimulated saliva were also collected in sterile tubes and 0.1 ml of whole saliva was diluted in 1 ml of reduced solution. The presence of A. actionomycetemcomitans was established using bacterial culture in trypticase soy bacitracin vancomycin selective media. Polymerase chain reaction (PCR) was used to differentiate highly from minimally leukotoxic strains in patients who presented A. actinomycetemcomitans in at least two sampled sites. RESULTS: A. actinomycetemcomitans was isolated from 63.63% of subgingival samples, 56.06% of saliva samples, and 45.45% of samples from mucous surfaces. No statistical difference was observed between subgingival and salivary occurrence of the microorganism. Linear regression showed an association between subgingival plaque and saliva (r(2) = 0.897; P = 0.015) and mucous membrane and saliva (r(2) = 0.152; P = 0.024). The same A. actinomycetemcomitans leukotoxic profile was observed in all sampled sites for a given patient. CONCLUSION: These results suggest that in advanced periodontitis, unstimulated saliva is representative of pooled subgingival plaque samples and its use is appropriate in the oral detection of A. actinomycetemcomitans.     

Subgingival distribution of A. actinomycetemcomitans in periodontitis

Abstract This investigation developed an experimental design that (1) detailed the distribution of A. actinomycetemcomitans in Subgingival plaque related to the level of serum antibody to this pathogen; (2) used broad based subgingival plaque sampling to allow a definition of the distribution of A. actinomycetemcomitans infection in periodontitis patients; (3) described the distribution of A. actinomycetemcomitans serotypes in patients and within sites; and, (4) assessed how this infection impacted upon local clinical symptoms of disease. We noted a significant positive relationship between the level of IgG anti-A. actinomycetemcomitans antibody and the frequency of teeth infected until nearly 13 teeth demonstrated an infection. Furthermore, the results showed a generally negative relationship between the antibody level and the burden of A. actinomycetemcomitans in the infected sites. Interproximal sites associated with first molar teeth were the predominant sites for subgingival colonization; incisors were also frequently infected in this population. The first molar teeth also exhibited the greatest level of A. actinomycetemcomitans while the incisors demonstrated a high level of A. actinomycetemcomitans in individual sites. The results clearly indicated the majority of the sites sampled were colonized by a single serotype of A. actinomycetemcomitans. We detected A. actinomycetemcomitans nearly 2 × times more frequently and a significant increase in the proportion of A. actinomycetemcomitans was found in samples obtained from teeth with bleeding on probing. The results also showed a significant trend for both pocket depth and attachment levels to be related to the presence and proportion of A. actinomycetemcomitans in the subgingival plaque. These findings detail the microbiological, immunological and clinical characteristics of a unique subset of periodontitis patients that appear to exhibit disease associated (caused?) with A. actinomycetemcomitans infection irrespective of clinical categorization. The results support a unique distribution of this microorganism in the subgingival ecology that is related to active host immune responses and clinical presentation of the tooth.     

Soluble Triggering Receptor Expressed on Myeloid Cells 1 (sTREM‐1) in Gingival Crevicular Fluid: Association With Clinical and Microbiologic Parameters

Background: Soluble triggering receptor expressed on myeloid cells 1 (sTREM‐1) belongs to the immunoglobulin superfamily and is involved in amplification of the inflammatory response to bacterial infection. This cross‐sectional study aims to investigate the levels of sTREM‐1 in gingival crevicular fluid (GCF) of individuals without periodontitis and with chronic periodontitis (CP) or generalized aggressive periodontitis (GAgP) and their association with the levels of key periodontal pathogens in subgingival plaque. Methods: GCF and subgingival plaque samples were obtained from healthy sites of participants without periodontitis (n = 20) and periodontitis sites of patients with CP (n = 22) and GAgP (n = 20). sTREM‐1 levels in GCF were measured by enzyme‐linked immunosorbent assay. Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans levels in subgingival plaque were analyzed by quantitative real‐time polymerase chain reaction. Results: sTREM‐1 levels in GCF were higher in CP and GAgP than healthy sites by 3.6‐ and 4.4‐fold, respectively, with no significant differences between the two forms of periodontitis. Moreover, sTREM‐1 levels in GCF were positively correlated with site‐specific clinical periodontal parameters and levels of P. gingivalis, T. denticola, and T. forsythia, but not A. actinomycetemcomitans, in subgingival plaque. Conclusion: Increased GCF levels of sTREM‐1 at diseased sites and their positive correlation with clinical and microbiologic parameters strengthen the association of this inflammatory marker with periodontitis.     

Microbial etiology of periodontal disease

Abstract Longitudinal studies with humans indicate that gingivitis is associated with an increased dental plaque mass. Also, prior to the onset of gingivitis, changes in the microflora towards a more complex bacterial composition frequently occur. On the other hand, recent cross sectional cultural studies generally do not reveal clear-cut differences between the composition of the subgingival microflora associated with healthy or inflamed gingivae. Also, some studies have demonstrated an enhanced cell-mediated immune response during the course of gingivitis to a variety of subgingival plaque bacteria. It has also been observed that plaques allowed to form on cleaned teeth for 2 or 3 days do not differ substantially in their microbial composition. However, long-term thorough oral hygiene performed at intervals of 48 h permits maintenance of gingival health, whereas that instituted at intervals of 72 h will lead eventually to gingivitis. Collectively, this evidence supports the concept that the etiology of gingivitis is bacteriologically nonspecific. Thus a large increase in the accumulation of bacteria on the tooth surface per se may have a greater pathogenic effect on the periodontal tissues than the relatively minor and inconsistent shifts in the microbial composition. The transition from gingivitis into periodontitis may be induced by changes in the pathogenic potential of subgingival plaque. Gram-negative rods appear to be specifically associated with periodontitis. A growing body of evidence implicates especially Bacteriodes asaccharolyticus as one of the responsible pathogens. Juvenile periodontitis (periodontosis) seems to be a distinct disease entity. Recent findings suggest abnormalities in peripheral blood polymorphonuclear leucocytes (PMNL) of patients with juvenile periodontitis. The subgingival microflora is different from that associated with periodontitis and the findings so far implicate Actinobacillus actinomycetemcomitans as an important pathogen. The bacterial etiology of acute necrotizing ulcerative gingivitis (ANUG) is still unclear. Satisfactory cultural studies have yet to be performed. The presence of spirochetes in the ulcerative lesions of the junctional epithelium does not necessarily imply that they play an important role in this disease entity. Future research on the bacteriology of periodontal disease should concentrate on longitudinal studies; particular attention should be paid to the change of gingivitis into periodontitis whereby animals as well as humans can be used. Improvements of sampling methods as well as precise and simple identification techniques of microorganisms are required.     

Value of some laboratory and clinical measurements in the treatment plan for advanced periodontitis

Abstract In our previous study, we reported that only 13 of 46 adult patients with advanced periodontitis responded well to initial non-surgical periodontal therapy. In the present follow-up study, the remaining 33 patients were randomly treated further using either modified Widman flap surgery or systemic metronidazole. The patients responding unsatisfactorily to this 2nd treatment phase, received supplementary systemic chemotherapy or surgery, respectively. By using this study design, we determined which baseline clinical variables and/or laboratory findings predicted the treatment outcome in these study patients. Clinical variables included the assessment of bleeding, suppuration, probing pocket depth, furcation lesions, relative attachment level and radiographic infrabony defects. Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were cultured from subgingival plaque samples. The specific IgG and IgA antibody levels against 5 serotypes of A. actinomycetemcomitans were determined in serum and saliva. Elastase-like. trypsin-like and general protease activities were assessed from saliva. The bivariate statistical analyses showed that the most pronounced difference between the patients responding well to initial non-surgical therapy (group MC n=13), to either supplementary surgery or chemotherapy (group FT1, n=11). or those responding to the complex therapy (group FT2, n=17), was the prior extent of periodontal destruction expressed as the proportion of ≥6 mm deep periodontal pockets. When multiple linear regression was used to investigate the influence of clinical and laboratory findings on the variation of treatment response between the 3 groups, the most significant explanatory factor was the simultaneous presence of subgingival A. actinomycetemcomitans and multiple deep periodontal pockets. None of the immunological or biochemical variables used had any further influence in the model. Pretreatment microbiological examination, especially for the detection of A. actinomycetemcomtians. seems to be a valuable laboratory screening method for identifying complex treatment need in adult patients with advanced periodontitis. However, the evaluation of the extent and pattern of periodontal breakdown remains crucial for choosing the treatment strategy including surgery and/or chemotherapy in A. actinomycetemcomitans-infected adult periodontitis patients.     

The distribution of Actinobacillus actinomycetemcomitans in human plaque

The association between Actinobacillus actinomycetemcomitans and periodontal disease in juveniles has been well documented. The purpose of this investigation was to determine the prevalence and proportions of A. actinomycetemcomitans in supragingival and subgingival plaque samples from the maxillary first molars of a large number of young adults. The study population included 284 adults, aged 20–40, ranging in periodontal disease status from healthy to moderate periodontitis but with the majority exhibiting early periodontal disease. The clinical characteristics of probing depth, attachment level, plaque index, and gingival index were measured. Supragingival and subgingival plaque samples were evaluated microscopically for microbial forms. They were also cultured on supplemented blood agar and various selective agar media including selective media for A. actinomycetemcomitans. The prevalence of A. actinomycetemcomitans in subgingival and supragingival plaque for individuals in the population was 13.0% (37/284) and 4.9% (14/284), respectively. Proportions of actinobacilli, based on total anaerobic counts, were found at or below 1% in 87% of 47 subgingival sites from 37 subjects. Supragingival and subgingival sites with actinobacilli were compared to sites without actinobacilli. Subgingival sites with A. actinomycetemcomitans had a significantly higher mean plaque index, with 79% of these sites having a plaque index greater than 1.0 compared to 30% of sites without actinobacilli. The mean gingival index, probing depth, and attachment level of sites with actinobacilli were also higher, but not significantly, than those without. Of the microbial forms enumerated, only spirochetes had a significantly higher mean proportion at subgingival sites when compared to sites without actinobacilli. Mean proportions of the cultivable microorganisms, Veillonella spp. and Streptococcus spp., were significantly lower at sites with A. actinomycetemcomitans. Differences in the mean proportions of certain microorganisms were compared between the 47 subgingival sites with actinobacilli divided into three groups by probing depth. Mean proportions of A. actinomycetemcomitans were significantly higher at intermediate probing depths between 3.0 and 5.0 mm compared to deeper sites with probing depths above 5.0 mm. On the other hand, dark-pigmented Bacteroides spp. mean proportions were significantly higher at deeper probing depths than at either intermediate or shallow, less than or equal to 3.0 mm, probing depths. There were no significant differences in the mean proportions of spirochetes between shallow, intermediate, or deeper probing depths of the 47 subgingival sites with actinobacilli.     

Postoperative bleeding tendency as a risk factor in Actinobacillus actinomycetemcomitans-associated periodontitis

Frequent bleeding on probing (BOP) has been considered a risk factor for recurrence of periodontitis. In the present study, 29 patients with Actinobacillus actinomycetemcomirans-associated periodontitis were enrolled in a carefully performed recall system. At 6 sites per tooth, periodontal probing depth (PPD), gingival index (GI), plaque index (PII) and BOP was assessed 6 weeks, 6 months, 1 and 2 years after comprehensive therapy. Professional toothcleaning and subgingival scaling at sites with PPD ≥ 5 mm and BOP was carried out every 2nd or 3rd month. Subgingival samples from 2 sites, a pooled subgingival sample, check mucosa, saliva and tongue samples were selectively cultivated for A. actinomycetemcomitans after 2 years. Following active therapy, 8 % sites had a PPD of ≥ 4 mm, whereas 21 % sites bled on probing. After 2 years, respective figures were 12 and 27 %. During maintenance, frequent BOP (≥3 times at 4 visits) had a predictive value of 0.133 to indicate an increase in PPD of ≥ 2 mm and a negative predictive value of 0.947. The predictive value of no bleeding to indicate a stable site was 0.972, the negative predictive value 0.078. There was evidence for heterogeneity of associations between increase in PPD of ≥ 2 mm and ≥ 3 times BOP among patients (X²₍₂₈₎ = 41.45, p < 0.05). Significant sources for the variation of weighted In-transformed estimates of individual odds ratios (range -0.83 to 6.21, median 1.52) were relative numbers of A. actinomycetemcomitans-positive samples 2 years after therapy, age, and mean % of PII 2 (R² =0.439, p<0.001). No association between increase in PPD and BOP was found in patients where A. actinomycetemcomitans was not recovered from any sample (X²_MH = 1.96), but A. actinomycetemcomitans-positive subjects still had inconsistent associations (X²_MH = 37.65. p < 0.01). Ignoring patient characteristics may be misleading in the search for risk factors for recurrence of the disease.     

Suppression of the periodontopathic microflora in localized juvenile periodontitis by systemic tetracycline

Abstract. Since recent studies have implicated Actinobacillus actinomycetemcomitans in the etiology of localized juvenile periodontitis, this investigation determined the effectiveness of subgingival debridement, topical Betadine Solution®, and systemic tetiacycline in suppressing subgingival A. actinomycetemcomitans and other microorganisms. A total of 20 deep periodontal pockets and 10 normal periodontal sites of 6 localized juvenile periodontitis patients was included in the study. Each patient was treated in 3 stages over a period of 22 weeks, and the result of treatment was monitored for an additional 38 weeks. The first stage of treatment included plaque control, as well as thorough scaling and root planing, composed of at least 6 h of debridement. No concomitant periodontal surgery was performed. In the second stage, Betadine saturated cotton gauze was inserted into the periodontal pockets for 10 min. Stage 3 involved systemic tetracycline therapy (1 g/day) for J4 days. The subgingival microflora was determined at frequent intervals by selective culturing of A. actinomycetemcomitans and Capnocytophaga and by direct microscopic examination. The clinical effect was assessed by measuring changes in probing periodontal attachment level, probing periodontal pocket depth, radiographic alveolar bone mass, and other relevant clinical parameters. Scaling and root planing reduced the total subgingival bacterial counts and the proportions of certain Gram-negative bacteria, but no periodontal pocket became free of A actinomycetemcomitans. Betadine application had little or no effect on the subgingival microflora. In contrast, tetracycline administered via the systemic route suppressed. A actinomycetemcomitans, Capnocytophaga, and spirochetes to low or undetectable levels in all test periodontal pockets. A, actinomycetemcomitans reappeared in 9 of the deep periodontal pockets after the administration of tetracycline. Most of these 9 pockets became free of detectable A. actinomycetemcomitans during the second week of tetracycline administration, whereas pockets which yielded no A. actinomycetemcomitans after tetracycline therapy became free of the organisms during the first week of tetracycline treatment. This data suggests that systemic tetracycline therapy of localized juvenile periodontitis should, as a practical rate, be continued for 3 weeks. Periodontal destruction continued in 4 deep pockets which all showed high posttetracycline A, actinomycetemcomitans counts. All 6 pockets which demonstrated a marked gain in periodontal attachment yielded no cultivable A. actinomycetemcomitans. No association was found between periodontal disease status and subgingival Capnocytophaga, spirochetes or motile rods. The present study indicates that A. actinomycetemcomitans is an important etiologic agent in localized juvenile periodontitis. Also, this study demonstrates that the effectiveness of therapy can be monitored by subgingival A. actinomycetemcomitans counts, and that periodontal A, actinomycetemcomitans infections cannot be resolved by root surface debridement alone but can be cured by systemic tetracycline therapy.