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.     

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.     

A longitudinal study of Actinobacillus actinomycetemcomitans in army recruits

During recruiting examinations 201 recruits, 18-25 yr old, were examined for subgingival and extracrevicular Actinobacillus actinomycetemcomitans. The organism was isolated in 55 subjects, most often at low levels. Cluster analysis revealed 3 clusters with no (A, n = 86) or minor (B, n = 92) periodontal disease and low DMF-S, as well as established periodontitis, increased DS and high DMF-S (C, n = 22). When leaving the 12-months' service, 105 recruits were re-examined (54 cluster A, 41 cluster B, 9 cluster C subjects, 1 recruit who was not clustered). An increase of periodontal probing depth (PPD) of 3 mm at 1 or more sites occurred in 33 subjects: 9 (17%) in cluster A, 16 (39%) in cluster B, 7 (78%) in cluster C and in the not-clustered recruit. Considerable variation in frequency distributions of PPD alterations was observed, therefore significant (p<0.1) mean increase (1-sample t-test) and skew g₁ (S-statistic) were additionally considered to define an “active” case. A total of 7 recruits (6.7%) met the criteria. Logistic regression analysis revealed a significant influence of self-reported smoking habits on activity status. Thus, heavy smokers (>20 cigarettes/d) had a 14-fold higher risk (p = 0.030) for developing or progressing periodontitis compared to non- or light smokers (< 10 cigarettes/d). In particular, cluster B recruits appeared to have a lower risk (p = 0.11) for developing periodontitis than cluster C recruits (established periodontitis, high DMF-S). A. actinomycetemcomitans was isolated in 29 recruits (27.6%) at baseline and 30 recruits (28.6%) after 12 months. Presence of the organism was not a risk factor for periodontitis. However, in active subjects, significantly more samples were only A. actinomycetemcomitans-positive at re-examination compared to inactive recruits. It was concluded that smoking is a significant risk factor for periodontitis. Subjects with established periodontitis tend to deteriorate further. A. actinomycetemcomitans seems not to increase the risk for developing or progressing periodontitis in this age group. Longer studies involving larger populations are needed to confirm these observations.     

Simultaneous isolation of Actinobacillus actinomycetemcomitans from subgingival and extracrevicular locations of the mouth

Abstract In the present study, a total of 619 subgingival and extracrevicular samples from 66 early-onset periodontitis, 42 adult periodontitis/gingivitis and 36 treated Actinobacillus actinomycetemcomitans-associated periodontitis patients were selectively cultivated for presence of A. actinomycetemcomitans. The organism was recovered from 68% cases with early-onset periodontitis, 24% cases with adult periodontitis/gingivitis and 50% of treated patients. Associations between recovery from pooled subgingival plaque and samples from extracrevicular locations as well as between different extracrevicular samples, were not heterogeneous with regard to different groups with the exception for cheek/saliva comparisons (odds ratios: early-onset periodontitis 825; adult periodontitis 8.1; treated patients 117; 0.05<p<0.1). For associations between recovery of A. actinomycetemcomitans from pooled subgingival plaque/extracrevicular samples, Mantel-Haenszel's odds ratios of between 12.2 and 21.6 were calculated (p<0.0001). The organism was isolated from 17 cheek mucosa samples of 18 patients identified as still harboring the organism after therapy. Present results point to the considerable value of cheek mucosa samples especially in treated patients to diagnose persistent A. actinomycetemcomitans colonization of the oral cavity.     

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.     

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.     

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.     

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.     

Suppression of subgingival Actinobacillus actinomycetemcomitans in localized juvenile periodontitis by systemic tetracycline

Abstract The current study assessed the clinical and microbiological effects of systemic antimicrobial therapy alone in Actinobacillus actinomycetemcomitans-infected adolescents with periodontal disease. The study involved 6 localized juvenile periodontitis patients 13–18 years of age, who harbored high numbers of A. actinomycetemcomitans: in subgingival plaque samples. The periodontal lesions were microbiologically monitored by selective culture, and clinically assessed for probing pocket depth and periodontal attachment level 3 months prior to baseline, and at 3, 6, 12, and 24 months posttreatment. Tetracycline-HCl (250 mg/ QID) was prescribed until 1 week after subgingival A. actinomycetemcomitans was no longer detectable or for a maximum of 8 weeks. During 3 months prior to treatment, pocket depth was unchanged, and was then significantly reduced from an average of 7.1 mm to 5.1 mm 12 months after treatment (p - 0.02). The mean change in clinical attachment level was a gain of 1.4 mm between baseline and 12 months (p= 0.02). 3 of the 6 patients were still infected with A. actinomycetemcomitans after 8 weeks of antibiotic therapy and 4 subjects were infected at 12 months. Numbers of A. actinomycetemcomitans were still suppressed in most lesions. There was a strong association between mean numbers of A. actinomycetemcomitans in periodontal pockets and mean change in probing attachment level at any given time point. For 22 available comparisons, derived from all time points, there was a strong association (r= 0.68) between subgingival A. actinomycetemcomitans and change in probing attachment level. 8 of 9 (89%; sensitivity) individual patient time intervals with “disease” (< 1.5 mm gain in probing attachment level) were tested positive (≥ 100 CFUJ, whereas 9 of 13 (69%; specificity) individual patient time intervals with “no disease” (≥ 1.5 mm gain in probing attachment level) were A. actinomycetemcomitans negative (< 100 CPU) (p= 0.007).     

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.     

Actinobacillus actinomycetemcomitans,Capnocytophaga and Porphyromonas gingivalis in subgingival plaque of adolescents with Down's syndrome

Levels of Actinobacillus actinomycetemcomitans, Capnocytophaga and Porphyromonas gingivalis were determined in subgingival plaque samples from 37 adolescents with Down's syndrome and 37 healthy controls matched with respect to age and sex. Gingival inflammation, supra- and subgingival calculus, periodontal pockets (>4 mm) and alveolar bone loss were registered. Alveolar bone loss was more frequent in Down's syndrome subjects (32%) than in the controls (3%). A. actinomycetemcomitans was detected in the subgingival plaque in 35% of the Down's syndrome adolescents and in 5% of the controls. On site level, A. actinomycetemcomitans and Capnocytophaga were more frequent in the subgingival plaque samples of Down's syndrome children than in those of controls. Comparing Down's syndrome subjects positive or negative for A. actinomycetemcomitans and Capnocytophaga, no significant differences were found in terms of gingival inflammation, periodontal pockets (>4 mm) or number of sites with alveolar bone loss. The results indicate an altered microbial composition of the subgingival plaque of Down's syndrome subjects compared with healthy controls, with higher frequency of A. actinomycetemcomitans.     

Microscopic spirochete counts in untreated subjects with and without periodontal tissue destruction

Abstract The purpose of the study was to determine microscopically the %s of spirochetes at sites without periodontal destruction in subjects with destructive periodontal diseases (cases) and in subjects free of it (controls), who had not received professional prophylaxis. From a sample of 164 individuals aged between 30–44 years living in rural and urban areas of Tanzania, cases and controls were selected. Cases (n=25) were selected who exihibited at least 3 teeth with pocket depth of >5 mm. The controls (n= 28) had no pockets deeper than 3 mm. From each subject, 1 subgingival plaque sample was taken at the mid point of the lingual surface of 1 of the upper premolars which showed bleeding on probing but no calculus and no pockets. In addition, one subgingival sample was obtained from a pocket. Pockets contained the highest %s of spirochetes, which confirms earlier findings. A significant difference in % of spirochetes between cases and controls was found at non-destructive sites, indicating a host effect on the subgingival microflora. However, the spirochete counts at non-destructive sites did not provide a reliable measure to identify subjects with destructive periodontal disease.     

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.     

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.     

Investigation and quantification of key periodontal pathogens in patients with type 2 diabetes

Field CA, Gidley MD, Preshaw PM, Jakubovics N. Investigation and quantification of key periodontal pathogens in patients with type 2 diabetes. J Periodont Res 2012; 47: 470–478. © 2012 John Wiley & Sons A/S Background and Objective: Diabetes is a recognized risk factor for periodontitis. There are conflicting data regarding whether healthy diabetic patients or diabetic patients with chronic periodontitis have an altered subgingival microbiota compared with nondiabetic individuals. The aim of the present study was to detect quantitative differences in selected periodontopathogens in the subgingival plaque of diabetic patients using TaqMan quantitative PCR. Material and Methods:  Type 2 diabetes mellitus patients with (n = 9) or without chronic periodontal disease (n = 15) were recruited and matched to nondiabetic control subjects (n = 12 periodontally healthy, n = 12 chronic periodontitis). Subgingival plaque samples were collected from deep (> 4 mm probing depth) and shallow sites (≤ 3 mm probing depth) using paper points, and Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Porphyromonas gingivalis were quantified. Results: Forty‐eight subjects (69 samples) were recruited. Marked differences were seen in the levels of all three bacterial species, relative to the total bacterial population, according to periodontal health status. Using real‐time quantitative PCR, bacterial counts for P. gingivalis were significantly higher in deep pockets of diabetic and nondiabetic subjects compared with periodontally healthy subjects (p < 0.05) but did not differ significantly between diabetics and nondiabetics. A. actinomycetemcomitans was detected in all groups in low quantities, and counts did not differ significantly between groups (p > 0.05). F. nucleatum was abundant in all groups, with no clear significant differences between groups. P. gingivalis was found in higher quantities in periodontitis than in periodontally healthy subjects (p < 0.05). Statistically significant positive correlations were identified between pocket depth and counts for all three species tested (p < 0.05). Conclusion: A. actinomycetemcomitans, F. nucleatum and P. gingivalis were present in significantly different quantities and proportions in subgingival plaque, according to periodontal disease status. No significant differences were identified between the subgingival microbiota of type 2 diabetes mellitus patients compared with nondiabetic subjects.     

Microbiological assays as predictors of the response to periodontal therapy

Thirty-four patients with periodontal disease each had subgingival plaque samples collected from four sites (one from each quadrant) in their mouths. The relative proportions of spirochaetes, motile rods and cocci were determined using dark field microscopy and the proportion of anaerobic to aerobic microorganisms was calculated after culture. In addition, clinical recordings were made at these sampled sites. The patients then underwent a course of periodontal treatment and were placed on a maintenance programme. The clinical recordings were repeated and the results examined to ascertain if the original microbiological or clinical measurements could have been used to predict the response to therapy.
Of the baseline recordings, the initial probing depth, the initial attachment level and the presence of suppuration all showed a positive correlation with the degree of pocket reduction or attachment gain produced by treatment. The percentage of cocci in the subgingival plaque correlated negatively with the treatment response. Suppuration seemed to be associated primarily with the original pocket depth while the percentage of cocci in subgingival plaque showed a true relationship with the amount of attachment gained after periodontal therapy. The significance of this finding is discussed.     

Monitoring untreated periodontal disease

Abstract The purpose of this study was to monitor clinical attachment levels, using a constant force probe, in patients with untreated periodontal disease, and to use darkfield microscopy to monitor changes in subgingival plaque. 10 patients with untreated disease were studied over 12 weeks. The parameters measured at baseline and every 4 weeks were probing depth, attachment level and bleeding. The subgingival microflora of the deepest site in each quadrant was examined by darkfield microscopy, using a Hellber counting chamber, at baseline and 12 weeks. The subgingival plaque from any site which lost more than 2 mm clinical attachment was also sampled and the microflora examined. Analysis of the results shows that 91 % of probing depths and attachment levels remained the same or within ± 1 mm. 3.5% of probing depths and 3.7% of attachment levels became deeper by 2 mm. 6.9% of probing depths and 4.5% of attachment levels became shallower by 2 mm. Only 6 sites out of 1029 showed loss of clinical attachment > 2 mm. Darkfield microscopy showed no differences in the proportion of microorganisms at the 6 sites which lost more than 2 mm of clinical attachment, compared with the baseline value. A surprising result was the tendency for probing depths and attachment levels to decrease, especially in deeper pockets. This study showed that none of the parameters monitored, i.e., probing depth. attachment level, bleeding or subgingival microflora. indicated which sites would lose attachment over a 12-week period.     

The effect of subgingival debridement on periodontal disease parameters and the subgingival microbiota

Abstract The aim of the present investigation was to analyse the effect of subgingival scaling and root planing in subjects who prior to treatment exercised meticulous supragingival plaque control. 300 subjects were examined at baseline and after 1 and 2 years without treatment. After the year 2 examination, 62 subjects were randomly selected for therapy. They were given detailed instruction in proper self-performed toothcleaning measures and were carefully monitored during the subsequent 2 years. Following the year-4 examination, 2 quadrants, 1 maxillary and 1 mandibular in each subject, were randomly selected for additional therapy. The teeth in the selected quadrants were exposed to subgingival scaling and root planing. The subgingival therapy was repeated until a site no longer bled on gentle probing. This basic therapy was completed within a 2-month period. All subjects were re-examined after another 12-month interval. The examinations at year 4 and 5 included assessment of plaque, gingivitis, probing pocket depth and analysis of samples obtained from the subgingival microbiota at 134 selected sites. The findings from the present study demonstrated: (i) that subgingival scaling and root planing were effective in eliminating subgingival plaque and gingivitis; (ii) that professional therapy resulted in a pronounced reduction of probing depth at sites which at year 4 had a probing depth >3 mm; (iii) that in non-scaled quadrants, the extension of self-performed plaque control resulted in a continued improvement of the periodontal conditions at sites which at year 4 were < 5 mm deep.     

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.     

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.