Early-onset periodontitis in Morocco is associated with the highly leukotoxic clone of Actinobacillus actinomycetemcomitans

A particular clone (JP2) of Actinobacillus actinomycetemcomitans with increased leukotoxin production has been isolated from individuals with early-onset periodontitis (EOP). The aim of this study was to determine the frequency of carriers of this clone and its association with EOP in Moroccan schoolchildren. Of 217 plaque samples, 131 (60.4%) were culture-positive for A. actinomycetemcomitans. A total of 19 of these isolates had a 530-bp deletion in the leukotoxin promoter region characteristic of the JP2 clone. A strong association between the presence of A. actinomycetemcomitans with the 530-bp deletion and EOP was found (adjusted OR = 29.4; 95% Cl = 8.3 - 104.4; p < 0.0005), while no association could be demonstrated between the presence of A. actinomycetemcomitans without the deletion and EOP (adjusted OR = 1.3; 95% CI = 0.5 -2.9; p = 0.750). The study demonstrates that the endemic presence, in a human population, of the highly leukotoxic JP2 clone may result in an unusually high prevalence of EOP.     

Association between sharing of toothbrushes, eating and drinking habits and the presence of Actinobacillus actinomycetemcomitans in Moroccan adolescents

BACKGROUND/AIMS: Actinobacillus actinomycetemcomitans is frequently detected in dental plaque collected from Moroccan adolescents, and has been shown to be associated with clinical attachment loss in this population. The aim of this study was to assess whether behaviors such as the sharing of toothbrushes, and eating and drinking habits were associated with the presence of A. actinomycetemcomitans in Moroccan adolescents. MATERIALS AND METHODS: A total of 121 adolescents were clinically examined. Interviews regarding sharing of toothbrushes, eating and drinking habits were performed, and plaque samples were collected and analyzed for A. actinomycetemcomitans with different leukotoxin promoter types by polymerase chain reaction. Based on eating and drinking habits, the study population was divided in a low risk behavior group (LRB) and a high risk behavior group (HRB). RESULTS: No association was found between the sharing of toothbrushes and the presence of A. actinomycetemcomitans. The odds ratios between the HRB and LRB group for being positive for the JP2 type, for non-JP2 types, and for any type of A. actinomycetemcomitans were 4.74 (95% CI 0.55; 40.71), 2.49 (95% CI 1.03; 5.97), and 2.97 (95% CI 1.28; 6.91), respectively. The difference in the mean number of teeth with a clinical attachment loss of > or = 3 mm between the HRB and the LRB group was 0.91(95% CI 0.09; 1.72). CONCLUSION: Sharing of toothbrushes does not seem to be associated with the presence of A. actinomycetemcomitans in young Moroccans. Eating and drinking habits conducive to exchange of saliva are positively associated with presence of A. actinomycetemcomitans, and with a higher level of clinical attachment loss.     

Detection of a highly toxic clone of Actinobacillus actinomycetemcomitans (JP2) in a Moroccan immigrant family with multiple cases of localized aggressive periodontitis

The JP2 clone of Actinobacillus actinomycetemcomitans, a high-leukotoxin-producing strain, characterized by a 530-basepair (bp) deletion in the promoter region of the leukotoxin gene operon and mainly found among individuals with African origin, is associated with localized aggressive periodontitis. The objective of the study was to examine the occurrence of periodontal disease in a Moroccan immigrant family living in Denmark in which the oldest son (14 year) was referred and treated for localized aggressive periodontitis. Further, the potential occurrence of the JP2 clone of A. actinomycetemcomitans in the family was examined. Here we present the clinical, radiographic, and microbiological findings from the family. Clinical and radiographic examination of the other family members revealed that 3 of 5 younger siblings had localized aggressive periodontitis, one had gingivitis and the mother had chronic periodontitis. Despite scaling followed by intensive maintenance therapy several family members, including the sibling with gingivitis, had further attachment loss at the 1-year examination. The JP2 clone of A. actinomycetemcomitans was isolated from subgingival plaque samples from 4 children with periodontitis. In contrast, it was not detected in plaque from the oldest boy, who had been treated for localized aggressive periodontitis by surgery combined with antibiotic therapy. The 4 children with periodontitis and colonized with the JP2 clone were treated by scaling and antibiotic administration. One month later the JP2 clone could still be detected in plaque samples. In conclusion, it is confirmed that members of immigrant families with African origin are potential carriers of the JP2 clone and that those families often have multiple family members with localized aggressive periodontitis. It is proposed that those families are given periodontal examination frequently to benefit from early diagnosis and treatment of the disease.     

Antibody reactive with Actinobacillus actinomycetemcomitans leukotoxin in early-onset periodontitis patients

The objective of this study was to determine whether a relationship exists between antibody reactive with the Actinobacillus actinomycetemcomitans leukotoxin and the severity of periodontal disease. Serum concentrations of antibody reactive with the leukotoxin were determined for 119 early-onset periodontitis patients and 59 non-periodontitis subjects using limiting dilution analysis on Western blots. Immunoglobulin G (IgG) antibody reactive with the A. actinomycetemcomitans leukotoxin ranged from undetectable to 29 jig/ml (mean = 3.13±0.97 μg/ml for the generalized early-onset periodontitis and 2.17±0.86 μg/ml for the localized juvenile periodontitis patients vs 0.32±0.24 μg/ml for 59 non-periodontitis controls), and the dominant subclass was IgGl. Analysis of the relationship between antibody reactive with A. actinomycetemcomitans sonicate, A. actinomycetemcomitans leukotoxin and attachment loss patterns indicates that seropositive generalized early-onset periodontitis patients had decreased attachment loss compared with patients lacking this antibody. The statistical relationship appeared to be stronger for the sonicate than the purified leukotoxin. These data suggest that antibody reactive with A. actinomycetemcomitans leukotoxin may be protective in early-onset periodontitis, but given that the sonicate appeared better than the leukotoxin alone, it is not likely that leukotoxin is the only antigen of importance to host defense.     

Early-onset periodontitis in Hispanic-American adolescents associated with A. actinomycetemcomitans

Abstract – This study examines the frequency of oral disease in an adolescent population, and assesses the relationship to Actinobacillus actinomycetemcomitans. A total of 470 eighth grade students from San Antonio, Texas, were examined clinically for number of teeth, frequency of gingival inflammation, frequency of sites with BOP. and frequency of sites with 3-5 mm pockets, and pockets >5 mm. The population ranged in age from 12 to 17 yr and was 93% Hispanic. Heavy accumulations of plaque and calculus were frequently observed and were associated with gingival inflammation, as 95.6% of the students exhibited bleeding on probing, and 99.6%. of the students presented with at least on quadrant of inflammation upon visual examination. Significantly, 25.7% of the students exhibited early-onset periodontitis (HOP) with 1.7% diagnosed as LJP. Many students exhibited substantial levels of plaque and calculus, but no clinical evidence of loss of attachment. Subjects with periodontitis (EOP or LJP) presented with elevated systemic IgG antibody to actinomycetemcomitans serotype b and subgingival plaque samples positive for the microorganism. These results describe the prevalence of EOP/LJP in an adolescent Hispanic population from South Texas. The findings support that actinomycetemcomitans may represent a pathogen in periodontitis and while oral health care may be poor, contact with the microorganism appears to be required to initiate disease in this population.     

Prevalence of aggressive periodontitis in school attendees in Uganda

AIM: The prevalence and severity of early onset periodontitis (EOP) among students attending secondary schools in two regions of Uganda was studied. MATERIAL AND METHODS: 690 students (393 males and 297 females) aged 12-25 years (mean 17 years), representing a range of tribal groups, were recruited from six schools in the peri-urban Central and rural Western regions of Uganda. The study subjects were clinically examined in field conditions by a single calibrated examiner to measure gingival recession and probing depth at six sites per tooth, with subsequent calculation of clinical periodontal attachment level for each site. Subjects exhibiting >or= 4 mm of clinical periodontal attachment loss at approximal surfaces of one or more teeth were classified with EOP. A structured written questionnaire obtained demographic characteristics of the study subjects. RESULTS: 199 (28.8%) study subjects showed clinical features of EOP, of which 16 (2.3%) subjects exhibited generalized EOP, 29 (4.2%) localized EOP, and 154 (22.3%) incidental EOP. The percentage of EOP-affected males was significantly higher than females (33.8% vs. 22.2%, P < 0.001). EOP prevalence tended to increase with increasing age, but no association was found between EOP prevalence and socioeconomic status or residency in urban vs. rural areas of Uganda. Molars and mandibular incisors generally demonstrated the highest occurrence of >or= 4 mm attachment loss. Clinical periodontal attachment loss of >or= 5 mm was mainly seen at first molars and incisors, suggesting that these two tooth types are first affected with attachment loss. Approximal tooth surfaces showed greater probing depth and attachment loss than buccal and lingual surfaces. Gingival recession was most prevalent at mandibular anterior teeth, whereas gingival margin coronal to CEJ was most frequently observed at second molars and maxillary incisors. CONCLUSION: A relatively high prevalence of EOP (28.8%) was found in young Ugandan school attendees, with 6.5% of these showing severe disease. EOP in Uganda was significantly more prevalent in males than females, and most frequently characterized by approximal involvement of molars and mandibular incisors. Etiologic and predisposing factors associated with the high occurrence of EOP in Uganda, as well as therapeutic and preventive measures of the disease in this population, remain to be delineated.     

Prevalence of Actinobacillus actinomycetemcomitans in an ethnic adult Chinese population

AIM: The aim of this study was to determine the prevalence and the structure of the leukotoxin promoter region of Actinobacillus actinomycetemcomitans in an ethnic Chinese population. METHOD: Subgingival plaque samples were collected from 42 patients with moderate to advanced periodontitis and 50 periodontally healthy patients. A. actinomycetemcomitans was detected directly from the crude subgingival plaque by PCR using leukotoxin gene specific primers. The presence of A. actinomycetemcomitans was determined by a single 285 bp PCR amplicon. RESULTS: A. actinomycetemcomitans was found to be present in the subgingival plaque of 68 out of a total of 92 patients examined (74%). 29 out of the 42 periodontitis patients tested were carriers of A. actinomycetemcomitans (69%). Among the periodontally healthy patients studied, 39 out of 50 subjects possessed the bacteria (78%). PCR analysis of the promoter region of the ltx operon revealed that none of the 42 moderate to advanced periodontitis patients examined harboured A. actinomycetemcomitans strains with the JP2-like promoter of the ltx operon, known to enhance leukotoxin expression. 2 out of the 27 advanced periodontitis patients clinically diagnosed as suffering from rapidly progressive periodontitis were found to be carriers of the mildly toxic strain of A. actinomycetemcomitans with the characteristic 652-like promoter. CONCLUSIONS: The high prevalence of A. actinomycetemcomitans, regardless of whether the subgingival samples were analysed from patients with healthy or diseased periodontium suggests that this bacterial species is part of the normal oral flora of ethnic Chinese. Our preliminary results also suggested that subjects who harboured the mildly toxic strain of A. actinomycetemcomitans were potentially susceptible to aggressive forms of periodontitis.     

The highly leukotoxic JP2 clone of Actinobacillus actinomycetemcomitans and progression of periodontal attachment loss

The JP2 clone of Actinobacillus actinomycetemcomitans has been implicated in the etiology of periodontitis in adolescents. The aim of this two-year longitudinal study was to describe clinical attachment loss (CAL) progression and to assess its association with baseline occurrence of the JP2 and non-JP2 types of A. actinomycetemcomitans. Clinical re-examination of 121 adolescents in Morocco was performed. Progression of CAL > or = 1 mm, > or = 2 mm, > or = 3 mm, and > or = 4 mm on at least one site was found in 58%, 48%, 22%, and 6% of the subjects, respectively. Subjects who, at baseline, harbored the JP2 clone had a significantly higher progression of CAL than did subjects harboring non-JP2 types of A. actinomycetemcomitans. Subjects harboring non-JP2 types displayed a marginally higher CAL progression than did subjects who were culture-negative for A. actinomycetemcomitans.     

Combined mechanical and antibiotic periodontal therapy in a case of Papillon-Lefèvre syndrome

BACKGROUND: Papillon Lefèvre syndrome (PLS) is a rare entity and, as such, it is almost impossible to evaluate an effective therapy in a randomized controlled study. The amount of success reported after therapy for prepubertal periodontitis (PP) in PLS is highly variable from case to case. The goal of this case report is to evaluate the effects of a combined mechanical and antibiotic periodontal therapy regimen in the management of PLS. METHODS: A male patient was diagnosed as suffering from PP associated with PLS at the age of 7 years. He showed hyperkeratosis of the palms and soles, as well as advanced periodontal disease already affecting permanent teeth with maximal probing depth and vertical attachment loss of 12 mm and 11 mm, respectively. Subgingival debridement was performed with simultaneous administration of oral 250 mg amoxicillin 3 times daily and 250 mg metronidazole twice daily for one week. Clinical parameters were assessed and subgingival plaque was collected from all teeth prior to therapy and 7 and 26 months after treatment. Selective cultures for A. actinomycetemcomitans were incubated for each individual tooth and DNA probe analysis was performed for various periodontal pathogens. RESULTS: Prior to combined mechanical and antibiotic treatment, all teeth but one harbored Actinobacillus actinomycetemcomitans subgingivally. However, at 7 and 26 months after therapy A. actinomycetemcomitans could be detected neither by culture nor by DNA probes. Clinical parameters improved markedly and teeth erupting after therapy did not exhibit attachment loss of more than 1.5 mm during the observation period. CONCLUSIONS: Eradication (suppression beneath detection levels) of A. actinomycetemcomitans seems to play a significant role in the successful treatment of localized prepubertal periodontitis in PLS.     

Gingival inflammation and subgingival calculus as determinants of disease progression in early-onset periodontitis

Abstract. This study was undertaken to test the hypothesis that gingival inflammation and dental calculus are important determinants of the development and progression of early-onset periodontitis. The study sample included 156 individuals who were 13–20 years old at baseline and who were examined 2× during 6 years to assess the attachment loss, gingival state and the presence of dental calculus. 33 (21%), 62 (40%), and 61 (39%) individuals were classified as having localized, generalized, or incidental EOP, respectively. The results showed an increase in the % of teeth with overt gingivitis and subgingival calculus, and also an increase in the % of teeth showing attachment loss during the 6-year period in ail classification groups. Of teeth with 0–2 mm attachment loss at the beginning of the study and which developed ≥3 mm attachment loss during the following 6 years, there were 2× as many teeth with overt gingival inflammation, and 4× more teeth with subgingival calculus at baseline than teeth without. Gingivitis and subgingival calculus when present at both examinations resulted in a stronger association with the development of new lesions than presence of these variables at baseline. Teeth with gingivitis at baseline had a significantly higher mean attachment loss during 6 years than teeth without gingivitis (p<0.0001), and teeth with subgingival calculus at baseline had a significantly higher mean attachment loss than teeth without subgingival calculus (p<0.0001), The presence of gingivitis and subgingival calculus at baseline and 6 years later was associated with the occurrence of even higher disease progression during this period. The association between gingival inflammation and subgingival calculus and the development and progression of attachment loss during the study period in the generalized and the localized EOP groups was significantly higher than the association in the incidental EOP group. In an appreciable % of the sites in all 3 groups, however, the presence of the 2 factors was not associated with attachment loss during 6 years. The results suggest a significant association between gingival inflammation and subgingival calculus and the development and progression of early-onset periodontitis.     

A novel insertion sequence increases the expression of leukotoxicity in Actinobacillus actinomycetemcomitans clinical isolates

BACKGROUND: The expression of leukotoxin varies among Actinobacillus actinomycetemcomitans strains and is dependent in part on the structure of the ltx promoter region. Highly leukotoxic strains, characterized by a 530 base pair (bp) deletion within the ltx promoter, have been associated with juvenile periodontitis in the United States and Europe. In the present study, we analyzed the ltx promoter structure to elucidate whether A. actinomycetemcomitans from Japanese periodontitis patients exhibits the highly toxic phenotype. METHODS: Forty-five A. actinomycetemcomitans strains, including 43 clinical isolates, the highly leukotoxic strain JP2, and a minimally leukotoxic strain 652 were used in the study. The ltx promoter structure was analyzed by polymerase chain reaction (PCR), with oligonucleotide primers focusing the ltx promoter region, and nucleotide sequencing. Leukotoxic activity was determined by trypan blue exclusion. Western blotting assay was performed to detect the level of leukotoxin polypeptide. RESULTS: A 495 bp PCR product was amplified from JP2, a 1025 bp product from 652 and 41 of the clinical isolates, and a 1926 bp product from the remaining two clinical isolates (AaIS1, AaIS2). Sequencing of the 1926 bp PCR fragment showed that it was similar to that of strain 652 but contained an 886 bp region that was identified as an insertion sequence (IS). Both AaIs strains expressed high levels of leukotoxicity, similar to strain JP2. In addition, a mutant (AaIS-) that had lost the IS element expressed a significantly lower level of leukotoxicity compared with AaIS strains. Furthermore, the levels of leukotoxin polypeptide expressed by these strains were consistent with their whole cell leukotoxicity. CONCLUSIONS: A. actinomycetemcomitans clinical strains which were isolated from Japanese periodontitis patients do not possess the 530 bp ltx promoter deletion. The results of this study suggest that a high level of leukotoxin expression correlates with the insertion of the transposable DNA element.     

Clinical, microbiological and immunological features of subjects with destructive periodontal diseases

76 subjects with prior evidence of destructive periodontal diseases were monitored clinically and immunologically every 2 months for up to 5 years. Clinical parameters measured included bleeding on probing, gingival redness, plaque accumulation, suppuration, pocket depth and attachment level. Blood samples were taken by venipuncture and serum antibody levels to a series of 18 subgingival species determined. 33 of these subjects showed evidence of active disease during the monitoring period, based on changes in attachment level measurements assessed using the tolerance method of analysis. Mean attachment loss in these 33 subjects varied from 1.4 mm to 9.0 (median value 3.4 mm) and subjects whose mean attachment level was above the median showed a higher % of pockets greater than 3 mm and more suppuration. Severity of gingival inflammation related poorly to mean attachment loss. Subgingival plaque samples were taken from the active site(s) and from control sites of equal pocket depth and attachment loss in the same active disease subjects, prior to therapy, for predominant cultivable microbiota studies. 50 randomly selected isolates were identified from each sample. Predominant cultivable species in 170 pretreatment active and inactive sites combined (8500 isolates) were enumerated. The most frequently detected species were F. nucleatum (112 sites) and S. intermedius (106 sites), although the predominant species in the samples from each subject differed. The distribution of putative pathogens differed among subjects. For example, A. actinomycetemcomitans was found in 21 samples in 11 subjects and B. forsythus was found in 18 samples from 10 individuals. Antibody response patterns to the 18 subgingival species also varied among subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Five-year maintenance follow-up of early-onset periodontitis patients

OBJECTIVES: The purpose of this study was to evaluate the clinical and microbiological status of patients with early-onset or aggressive periodontitis (EOP) who had received supportive periodontal care (SPC) every 3-6 months for a period of 5 years, following active periodontal treatment. MATERIAL AND METHODS: The study population consisted of 25 individuals with early-onset periodontitis. Clinical examination and recordings of probing pocket depth (PPD) and clinical attachment level (CAL) were performed at baseline prior to treatment (T0), 3 months following the termination of active periodontal treatment (T1) and annually at the SPC appointments (T2,T3,T4,T5). Microbiological samples were obtained at the 5-year SPC (T5). Subgingival plaque samples for each individual were collected from one deep pocket (>5 mm), based on pretreatment measurements, randomly selected in each quadrant. The levels of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis and Treponema denticola were determined using oligonucleotide probe hybridization. RESULTS: During the 5-year period, the mean of SPC/patient was 12.7 sessions. A significant improvement was observed in PPD, CAL, gingival bleeding index and suppuration following treatment. However, between T1 and T5, 134 sites in 20 patients deteriorated with a CAL loss of> or =2 mm. Out of these 134 sites showing disease progression, microbial samples were randomly obtained in 13 sites (9.7%) from 8 patients. Among other factors, smoking and stress were found to have significant predictive value on the future attachment loss. P. gingivalis, T. denticola and total bacterial load were statistically significantly higher in patients who experienced disease progression during the 5-year maintenance period. CONCLUSIONS: For most EOP patients, regular SPC was effective in maintaining clinical and microbiological improvements attained after active periodontal therapy. However, a small percentage of sites was identified as progressive in 20 patients. Variables found to be related to periodontal progression were the presence of as well as the high bacterial counts of P. gingivalis, T. denticola and total bacterial load, number of acute episodes, number of teeth lost, smoking and stress.     

A short-term clinical and microbial evaluation of periodontal therapy associated with amalgam overhang removal

BACKGROUND: This study evaluated the effect of periodontal therapy plus amalgam overhang removal (PT+AOR) on periodontal status and the presence of Actinobacillus actinomycetemcomitans and Streptococcus mutans and compared two microbiological sampling techniques. METHODS: Molar teeth with Class II overhang restorations were selected as the test group, and homologous sound teeth were selected as the control group. Periodontal probing depth (PD), clinical attachment level (CAL), and plaque and gingival indices were measured, and restorations were evaluated using radiographs and clinical exploration at baseline (T1) and 90 days after PT+AOR (T2). Microbial samples were taken with dental floss and paper points at T1 and T2. S. mutans and A. actinomycetemcomitans were detected using culture and commercial kits. RESULTS: Mean values of plaque and gingival indices did not show statistically significant differences between test and control teeth between T1 and T2. At T2, the mean CAL decreased among test teeth, and the number of test teeth positive for A. actinomycetemcomitans showed a decrease, whereas positive samples for S. mutans increased. At T1, an association between the two sampling techniques for both bacteria was found. At T2, dental floss presented low sensitivity values for A. actinomycetemcomitans, whereas paper points showed low sensitivity for S. mutans. CONCLUSIONS: PT+AOR showed a beneficial effect on clinical parameters and a decrease of A. actinomycetemcomitans. At T1, both sampling techniques showed appropriate results. At T2, the use of paper points was a more sensitive sampling technique for isolate A. actinomycetemcomitans, whereas dental floss was found to be an alternative sampling method for isolate S. mutans.     

Periodontal pathogens in the shallow pockets of immigrants from developing countries

The aim of this study was to examine the distribution of typical periodontitis-associated microorganisms in refugees arriving from non-industrialized countries, and to relate the presence of these organisms to the periodontal condition of the subjects. Thirty males between 35-44 years of age were surveyed. Dental plaque, calculus, gingivitis, loss of attachment, and probing depths were recorded for all surfaces. A total of 90 microbiological samples were taken with paper points from mesial sites of teeth 16, 36 and 41. Microbiological test sites were grouped by probing depths and loss of attachment. Only 16.8% of all surfaces had probing depths > 3 mm, although 90.7% of surfaces had loss of attachment > 1 mm. Twenty-one sites with obvious periodontal destruction (PD > 3 mm, LA > 2 mm) showed the greatest recovery of Porphyromonas gingivalis (66.7%). However, 51 sites with minimal periodontal disease (PD < or = 3 mm, LA < 2 mm) and with no gingival recession also showed a relatively high detection frequency of P. gingivalis (34.1%). Twenty-four of these samples came from 12 patients with no pockets > 5 mm and with less than 10% of all sites yielding pockets > 3 mm. The detection frequencies of Prevotella intermedia (91.6%), Bacteroides forsythus (25.0%), Wolinella spp. (33.3%) and Actinobacillus actinomycetemcomitans (50.0%) were similar in these sites compared with periodontitis sites. Morphologically distinct isolates, from 19 individuals positive for A. actinomycetemcomitans, were serotyped by indirect immunofluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of Actinobacillus actinomycetemcomitans isolated from young Chinese aggressive periodontitis patients

OBJECTIVE: This study characterized Actinobacillus actinomycetemcomitans isolates from young Chinese aggressive periodontitis patients. METHODS: Subgingival plaque samples (two/subject) were collected from diseased subjects < 25 years old (n = 9, mean age 21.1 +/- 1.6 years) and age-matched periodontitis-free controls (n = 47, mean age 22.0 +/- 1.1 years). Selective and anaerobic culture were used. The serotype, leukotoxin gene (ltx) operon promoter and the cytolethal distending toxin (cdt) genes complex of the A. actinomycetemcomitans isolates were investigated. Effects of the isolates on non-keratinizing periodontal ligament epithelial cells monolayer were studied. RESULTS: Diseased subjects had significantly higher full-mouth bleeding score (p = 0.002) and total viable counts from plaque samples (7.2 x 10(6) vs. 2.1 x 10(5) CFU/paperpoint, p < 0.005). A. actinomycetemcomitans was isolated from 67%/56% or 6%/4% of diseased or controls subject/sites, respectively (p < 0.001). The proportion of A. actinomycetemcomitans isolatable from aggressive periodontitis or periodontitis-free associated subgingival plaque was low (0.7% vs. 0.1%, p < 0.02). The serotype of the isolates was characterized. All isolates possessed 652-like ltx gene promoter and all but one serotype c isolate from a diseased patient had intact cdtABC genes. That particular strain appeared to confer the least cellular damages on periodontal ligament epithelial monolayer compared to others. CONCLUSION: This preliminary study confirmed the notion of increased prevalence and quantity of A. actinomycetemcomitans associated with aggressive periodontitis in young patients. The overall ltx promoter and cdt characteristics of the A. actinomycetemcomitans isolates, however, were similar among the diseased and control groups. A strain lacking the cdtABC gene appeared to be less damaging to a periodontal ligament epithelial cell model. Further studies therefore are warranted to clarify the pathogenic role and potentials of A. actinomycetemcomitans in aggressive periodontitis.     

Untreated periodontal disease in Indonesian adolescents

BACKGROUND/AIMS: In an Indonesian population deprived of regular dental care, the experienced progression of disease between baseline (1987) and follow-up (1994) was investigated in relation to the composition of the subgingival microbiota at follow-up. At baseline the age ranged from 15 to 25 years. Clinical and microbiological evaluation was completed in 158 of the 167 subjects available at follow-up. METHODS: Plaque index (PI), pocket depth (PD), bleeding on probing (BOP), and attachment loss (AL) were scored at the approximal surfaces of all teeth and subgingival calculus on the approximal surfaces of the Ramfjord teeth only (number of sites with subgingival calculus: NSC). A pooled sample of the deepest pocket in each quadrant was evaluated using microbiological culture techniques. RESULTS: At baseline the mean values of the clinical parameters were AL=0.35 mm, PI=1.01, BOP=0.80 PD=3.25 mm and NSC=6.04 and at follow-up AL=0.75 mm, PI=1.16, BOP=1.19, PD=3.34 mm and NSC=5.85. All parameters except PD and NSC showed a statistically significant increase. At follow-up the prevalence of Actinobacillus actinomycetemcomitans was 40%, of Porphyromonas gingivalis 67%, of Prevotella intermedia 66%, of Fusobacterium nucleatum 79%, of Bacteroides forsythus 16%, of Campylobacter rectus 4%, and of P. micros 6%. No differences in clinical parameters were found between groups with or without these micro-organisms. In 129 subjects AL of > or =2 mm at > or =1 site was found. Logistic regression showed three significant odds-ratio's for experienced progressive periodontitis: Plaque index (12.2), gender (3.4) and Actinobacillus actinomycetemcomitans (2.9). CONCLUSIONS: The results of this retrospective study suggest that plaque is the most important parameter related to experienced disease progression, and that the presence of A. actinomycetemcomitans may be associated with increased chance of disease progression.     

Risk indicators for periodontal disease in a remote Canadian community--a dental practice-based study

OBJECTIVES: The purpose of this cross-sectional study was to identify risk markers and risk indicators for periodontal attachment loss in a remote Canadian community. Of special interest was the association between smoking and periodontal disease experience. METHODS: Data were collected from a convenience sample of 187 adult patients attending a dental office in a rural community located in Northern Ontario. Information was obtained via a questionnaire and a periodontal examination. The questionnaire included the use of dental services, self-care behaviors, general health status, smoking, and personal characteristics. Periodontal health was assessed using the mean periodontal attachment loss (MPAL), measured at two sites on all remaining teeth and the proportions of sites examined with loss of 2 mm or more and 5 mm or more. Plaque scores and measures of the number of missing teeth also were obtained. The relationships between mean periodontal attachment loss, the proportion of sites with 5 mm or more of loss and independent variables such as age, sex, current smoking status, mean tooth plaque scores, flossing frequency, and regularity of preventive dental visits were examined in bivariate and multivariate analyses. RESULTS: The data revealed a mean periodontal attachment loss of 3.9 mm (SD=1.5). The mean proportion of sites examined with loss of 2 mm or more was 0.89 and the mean proportion with loss of 5 mm or more was 0.35. In linear regression analysis, plaque scores, the number of missing teeth, age, current smoking status, regularity of dental visits, and flossing frequency had statistically significant independent effects and explained 60.0 percent of the variance in mean periodontal attachment loss. Just over 30 percent of subjects had severe periodontal disease, defined as 50 percent or more of sites examined with loss of 5 mm or more. In logistic regression analysis, missing teeth, dental visiting, smoking status, age, and flossing frequency had significant independent effects. The strongest association observed was with smoking, which had an odds ratio of 6.3. The logistic regression model correctly predicted 64.3 percent of cases with severe disease. CONCLUSIONS: The data indicate that the periodontal health of these patients is poor. Risk indicators or markers of poor periodontal health in the population studied included missing teeth, plaque scores, age, current smoking status, regularity of dental visits, and flossing frequency. This supports previous findings that behavioral factors play an important role in periodontal disease.     

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.     

Clinical immunologic and microbiologic features of active disease sites in juvenile periodontitis

Eight juvenile periodontitis (JP) patients with progressing disease were evaluated for clinical, immunologic, and microbiologic features. Clinically, bleeding on probing, pocket depth, and attachment level were unrelated to progressing disease. Only Actinobacillus actinomycetemcomitans was related to a marked increase in attachment loss when examined on both a site and patient basis. Eikenella corrodens was significantly elevated in progressing sites with A. actinomycetemcomitans as opposed to non-progressing sites harboring A. actinomycetemcomitans. Eikenella corrodens may function synergistically with A. actinomycetemcomitans to enhance disease in JP patients. Darkfield microscopy was of no value in distinguishing disease activity. All patients screened had elevated serum IgG levels to the same serotype of A. actinomycetemcomitans as that isolated from the subgingival flora. Other elevated serum IgG responses were noted to various organisms including F. nucleatum. B. intermedius, B. gracilus, B. gingivalis and E. corrodens.