Search

Recent studies of the dental plaque bacteria associated with the various forms of early-onset periodontitis confirm the importance of target periodontal pathogens such as Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Prevotella intermedia, and Porphyromonas gingivalis in these diseases. A. actinomycetemcomitans strains exhibit a wide range of variability in leukotoxin production. By virtue of a unique promoter for the leukotoxin (ltx) operon, highly leukotoxic A. actinomycetemcomitans strains (e.g., JP2) express 10- to 20-times greater levels of leukotoxin than minimally toxic strains (e.g., 652). In dot blot hybridization and polymerase chain reaction (PCR) assays, the distribution of leukotoxic A. actinomycetemcomitans was examined among 165 fresh isolates and strains from our culture collection obtained from 91 human patients and non-human primates. Highly leukotoxic A. actinomycetemcomitans strains were found in 22% of the subjects and represented 28% of the isolates examined. This is a much higher prevalence than reported in a similar survey of A. actinomycetemcomitans strains from Northern Europe. Patients harboring the highly leukotoxic strains were much younger (mean age 12.7 years) than those harboring minimally toxic A. actinomycetemcomitans (mean age 25.5 years). In addition, patients with localized juvenile periodontitis were shown to have a substantially higher prevalence of highly leukotoxic strains than healthy individuals or those with adult periodontitis. Fifty-seven percent of the localized juvenile periodontitis patients harbored these strains and 64% of the isolates obtained from these patients were highly toxic A. actinomycetemcomitans. No highly toxic strains were identified from healthy individuals or from patients with adult periodontitis. The polymerase chain reaction assay could readily identify and distinguish the ltx promoters from highly toxic and minimally toxic A. actinomycetemcomitans in whole plaque samples. These data point to the importance of specific A. actinomycetemcomitans strains, as characterized by their expression of high levels of leukotoxin, in the pathogenesis of certain types of early-onset periodontitis and, possibly, other forms of rapidly progressing periodontitis. J Periodontol 1996;67:282-290.

Dentists and other health care professionals are familiar with the impact of tobacco on oral and general health. However, oral health care professionals do not often provide tobacco-cessation counseling to their patients, thus reflecting a significant disconnect between research and clinical practice. This report demonstrates the benefits of tobacco cessation in resolving oral lesions and improving overall periodontal and oral health.A 51-year-old white male presented to the University at Buffalo, School of Dental Medicine clinic requesting an oral and periodontal examination as part of a presurgical protocol prior to cardiac surgery. A review of the patient's history from a health questionnaire revealed that he was using smokeless tobacco every day. An oral examination revealed several white lesions (5 x 10 mm) on the maxillary right and left labial mucosa. The patient was provided with tobacco-cessation counseling as well as oral hygiene instructions and professional dental prophylaxis.An oral examination 2 weeks after tobacco cessation revealed complete resolution of the oral lesions and overall improvement of periodontal and oral health.Although the findings presented in this article are based only on a single case report, the improvement in the patient's oral health after cessation of tobacco use was dramatic and reinforces the belief that tobacco-cessation counseling should be a routine component of the standard of care for tobacco-using patients.

Periodontitis is a local inflammatory process mediating destruction of periodontal tissues triggered by bacterial insult. However, this disease is also characterized by systemic inflammatory host responses that may contribute, in part, to the recently reported higher risk for cardiovascular disease (CVD) among patients with periodontitis. Moderate elevation of C-reactive protein (CRP) has been found to be a predictor of increased risk for CVD. Elevated CRP levels in periodontal patients have been reported by several groups. In this study, we examined whether CRP plasma levels are increased in periodontitis and if there is a relation to severity of periodontal disease and to the periodontal microflora.CRP serum levels were assessed using radial immunodiffusion assay in 174 subjects, 59 with moderate mean clinical attachment loss (AL) (2.39+/-0.29 mm) and 50 with high AL (3.79+/-0.86 mm) as compared to 65 periodontally healthy controls (AL, 1.74+/-0.18 mm). Clinical attachment loss, probing depths, and percentage of periodontal pocket sitesor =5 mm were measured. The presence of periodontal pathogens Porphyromonas gingivalis (P.g.), Prevotella intermedia (P.i.), Campylobacter recta (C.r.), and Bacteroides forsythus (B.f.) in subgingival plaque samples was measured by immunofluorescence microscopy.Statistically significant increases in CRP levels were observed in subjects with periodontal disease when compared to healthy controls (P= 0.036). Subjects with high levels of mean clinical attachment loss had significantly higher mean CRP levels (4.06+/-5.55 mg/l) than controls (1.70+/-1.91 mg/l), P= 0.011. The CRP levels were adjusted for factors known to be associated with elevated CRP, including age, smoking, body mass index (BMI), triglycerides, and cholesterol. Age and BMI were found to be significant covariates. The reported range for CRP as a risk factor for CVD, peripheral vascular diseases, or stroke is 1.34 mg/l to 6.45 mg/l and the mean of this range is 3 mg/l. The percentage of subjects with elevated levels of CRPor = 3 mm was significantly higher in the high clinical AL group (38%; 95% Cl: 26.7%, 49.3%) when compared to the control group (16.9%; 95% CI: 9.25%, 24.5%), P= 0.011. The presence of periodontal pathogens P.g., P.i., C.r., and B.f. in subgingival samples was positively associated with elevated CRP levels (P= 0.029).The extent of increase in CRP levels in periodontitis patients depends on the severity of the disease after adjusting for age, smoking, body mass index, triglycerides, and cholesterol. Also, there are elevated levels of CRP associated with infection with subgingival organisms often associated with periodontal disease, including P.g., P.i., C.r., and B.f. Recent investigations emphasized the role of moderate elevated CRP plasma levels as a risk factor for CVD. The positive correlation between CRP and periodontal disease might be a possible underlying pathway in the association between periodontal disease and the observed higher risk for CVD in these patients.

Recent studies suggest that chronic infections including those associated with periodontitis increase the risk for coronary vascular disease (CVD) and stroke. We hypothesize that oral microorganisms including periodontal bacterial pathogens enter the blood stream during transient bacteremias where they may play a role in the development and progression of atherosclerosis leading to CVD.To test this hypothesis, 50 human specimens obtained during carotid endarterectomy were examined for the presence of Chlamydia pneumoniae, human cytomegalovirus, and bacterial 16S ribosomal RNA using specific oligonucleotide primers in polymerase chain reaction (PCR) assays. Approximately 100 ng of chromosomal DNA was extracted from each specimen and then amplified using standard conditions (30 cycles of 30 seconds at 95 degrees C, 30 seconds at 55 degrees C, and 30 seconds at 72 degrees C). Bacterial 16S rDNA was amplified using 2 synthetic oligonucleotide primers specific for eubacteria. The PCR product generated with the eubacterial primers was transferred to a charged nylon membrane and probed with digoxigenin-labeled synthetic oligonucleotides specific for Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, and Prevotella intermedia.Eighty percent of the 50 endarterectomy specimens were positive in 1 or more of the PCR assays. Thirty-eight percent were positive for HCMV and 18% percent were positive for C. pneumoniae. PCR assays for bacterial 16S rDNA also indicated the presence of bacteria in 72% of the surgical specimens. Subsequent hybridization of the bacterial 16S rDNA positive specimens with species-specific oligonucleotide probes revealed that 44% of the 50 atheromas were positive for at least one of the target periodontal pathogens. Thirty percent of the surgical specimens were positive for B. forsythus, 26% were positive for P. gingivalis, 18% were positive for A. actinomycetemcomitans, and 14% were positive for P. intermedia. In the surgical specimens positive for periodontal pathogens, more than 1 species was most often detected. Thirteen (59%) of the 22 periodontal pathogen-positive surgical specimens were positive for 2 or more of the target species.Periodontal pathogens are present in atherosclerotic plaques where, like other infectious microorganisms such as C. pneumoniae, they may play a role in the development and progression of atherosclerosis leading to coronary vascular disease and other clinical sequelae.

The present longitudinal study was designed to explore the long-term efficacy of guided tissue regeneration (GTR) in Class II furcation defects and establish the factors that might be responsible for modifying this response. Subjects with two or more mandibular molars, one of which had Class II furcation defects, received the hygienic phase of therapy followed by baseline clinical measurements and subgingival plaque sampling. GTR procedure was performed in furcation defect sites using expanded polytetrafluoroethylene (ePTFE) membranes, while the other non-furcated molars received only scaling and root planning. Twenty-eight subjects (13 females, 15 males) aged 27 to 66 were included in this longitudinal analysis. Post-surgical treatment included routine home care supplemented with daily chlohexidine rinse and systemic tetracycline. Membranes were retrieved 4 to 6 weeks after surgery. During the first year, patients were initially seen bi-weekly and subsequently monthly for professional prophylaxis. At the end of this year, clinical measurements and samples were obtained. For the next 2 years, patients were seen bi-annually for maintenance visits. Clinical measurements and microbiological samples were then repeated. Next, a tighter maintenance protocol was established and patients were seen quarterly for scaling and oral hygiene reinforcement. Final measurements and samples were taken again 1 year later (4 years postoperative). Significant probing reduction (3.00 mm) and gain in horizontal attachment (2.59 mm) were obtained 1 year postsurgery for the GTR sites. These changes were maintained over 4 years with a slight decline at the end of year 3. Changes in probing depth (PD) from year 1 to 4 served to dichotomize the sites into stable (delta PDor = 0.9 mm), and unstable (PD increaseor = 1 mm). Of the 54 sites available for this analysis only 5 (9.3%) were unstable while 49 (90.7%) were stable or even further improved. Sites which exhibited minimal or no plaque (plaque index [PI]or = 1) over the tight maintenance period had a further decrease in mean probing depth (0.43 mm) compared with a slight increase (-0.06 mm) in mean probing depth in sites with PIor = 2 mm (P = 0.0235). The same phenomenon was observed for changes in relative attachment level (RAL): mean gain in RAL was 0.61 mm compared to 0.25 mm for the 2 groups, respectively (P = 0.07). Actinobacillus actinomycetemcomitans was only isolated from 2 sites at year 3, and none at year 4, compared to 21.45% of the sites at baseline. Porphyromonas gingivalis positive sites showed a continual decline over the years: 14.28% at baseline, 10.71% at year 1, and 5.1% at year 4. On the contrary, Prevotella intermedia (Pi) and Bacteroides forsythus (Bf) infected sites remained at approximately the same rate throughout the 4 years of the study (40% to 50% and 30% to 40% for Pi and Bf, respectively). Of these, Pi-infected sites exhibited less favorable clinical results compared to sites which were not infected with this microorganism. In summary, furcation defects treated with membrane barriers can be maintained in health for at least 4 years; however, good oral hygiene and frequent recall visits as part of a complete anti-infective therapy are essential. Finally, once treated, these teeth are comparable to similar molar teeth with no previous history of furcation pathosis.

This study examined the risk indicators for alveolar bone loss associated with periodontal infection. A cross-section of 1,361 subjects aged 25 to 74 years, from Erie County, NY were evaluated for interproximal alveolar bone loss and potential explanatory variables including age, gender, history of systemic diseases, smoking, and presence of 8 subgingival bacteria. Interproximal alveolar bone loss was measured from the alveolar crest to the CEJ and a mean computed for each subject. The mean bone loss per subject (BL) ranged from 0.4 to 8.8 mm, and this outcome variable was grouped into 4 ordered categories. The degree of association between the explanatory variables and BL was examined utilizing an ordinal stepwise logistic regression model. Factors which were positively associated with more severe bone loss included subgingival colonization with B. forsythus (O.R. 2.52; 95% CI: 1.98 to 3.17) or P. gingivalis (O.R. 1.73; 95% CI: 1.27 to 2.37), race (Native American, Asian, or Pacific Islanders) with an O.R. 2.40 (95% CI: 1.21 to 4.79), and gender with males having higher odds than females. Smokers had greater odds for more severe bone loss compared to non-smokers ranging from 3.25 (95% CI: 2.33 to 4.54) to 7.28 (95% CI: 5.09 to 10.31) for light and heavy smokers, respectively. Individuals at older ages also showed more severe levels of bone loss. History of kidney disease (O.R. 0.55; 95% CI: 0.35 to 0.89) and history of allergies (O.R. 0.76; 95% CI: 0.59 to 0.98) were inversely associated with severity of bone loss.(ABSTRACT TRUNCATED AT 250 WORDS)

This study evaluated the effect of periodontal therapy on clinical and microbiological parameters in 23 subjects with severe generalized early onset periodontitis. Therapy consisted of oral hygiene instruction and root planing and scaling, followed 3 months later by open flap debridement. Subjects were monitored for both clinical measures and levels of Actinobacillus actinomycetemcomitans and Porphyromas gingivalis as identified by indirect immunofluoresence. Clinical and microbiological evaluations were done at the start of the study, 3 months after the completion of root planing and scaling and 3 months after open flap debridement. Mean probing depth was reduced by both root planing and scaling and open flap debridement and the level of reduction demonstrated by both phases of therapy was similar to reductions found in studies that utilized subjects with chronic adult periodontitis. In contrast, reductions in attachment level due to the two phases of therapy, demonstrated in previous studies of subjects with adult periodontitis were not found in the young adult subjects with severe periodontal disease utilized in this study. Levels of A. actinomycetemcomitans were not significantly affected by root planing and scaling, but were reduced by open flap debridement. P. gingivalis was virtually eliminated by root planing and scaling, demonstrating that the two bacterial types respond differently to periodontal therapy. These changes in microbiological parameters were similar to those found in studies of localized juvenile periodontitis subjects, where surgery or antibiotics have been shown to be necessary to reduce levels of A. actinomycetemcomitans.

Specific risk indicators associated with either susceptibility or resistance to severe forms of periodontal disease were evaluated in a cross-section of 1,426 subjects, 25 to 74 years of age, mostly metropolitan dwellers, residing in Erie County, New York, and surrounding areas. The study sample exhibited a wide range of periodontal disease experience defined by different levels of attachment loss. Therefore, it was possible to accurately assess associations between the extent of periodontal disease and patient characteristics including age, smoking, systemic diseases, exposure to occupational hazards, and subgingival microbial flora. Age was the factor most strongly associated with attachment loss, with odds ratios for subjects 35 to 44 years old ranging from 1.72 (95% CI: 1.18 to 2.49) to 9.01 (5.86 to 13.89) for subjects 65 to 74 years old. Diabetes mellitus was the only systemic disease positively associated with attachment loss with an odds ratio of 2.32 (95% CI: 1.17-4.60). Smoking had relative risks ranging from 2.05 (95% CI: 1.47-2.87) for light smokers increasing to 4.75 (95% CI: 3.28-6.91) for heavy smokers. The presence of two bacteria, Porphyromonas gingivalis and Bacteroides forsythus, in the subgingival flora represented risks of 1.59 (95% CI: 1.11-2.25) and 2.45 (95% CI: 1.87-3.24), respectively. Our results show that age, smoking, diabetes mellitus, and the presence of subgingival P. gingivalis and B. forsythus are risk indicators for attachment loss. These associations remain valid after controlling for gender, socioeconomic status, income, education, and oral hygiene status expressed in terms of supragingival plaque accumulation and subgingival calculus. Longitudinal, intervention, and etiology-focused studies will establish whether these indicators are true risk factors.

The primary objectives of this double-blind, controlled clinical trial were to assess factor(s) which affect the success of guided tissue regeneration (GTR) procedures in mandibular Class II buccal furcation defects. Thirty subjects, with mandibular Class II furcation defects, were randomly assigned to one of two treatment groups; patients in Group A received oral hygiene instructions with scaling and root planing, while subjects in Group B received similar treatment but without subgingival scaling and root planing at the affected site. After initial oral hygiene instructions and scaling and root planing, GTR surgery was performed using ePTFE barrier membranes. Membranes were retrieved at 6 weeks and subjected to histological examination. Twelve months after regenerative therapy, clinical measurements and re-entry surgical measurements were repeated. Probing reduction (2.61 mm), horizontal probing attachment gain (2.59 mm), and vertical probing attachment gain (0.95 mm) were all significantly better compared to baseline. Likewise, significant improvements in furcation volume (8.0 microliters) and in bone measurements were observed at re-entry. There was no discernible difference between subjects for whom complete anti-infective therapy was deferred to the time of the surgery (Group B) compared to subjects in whom complete anti-infective therapy was performed as part of the hygienic phase of therapy (Group A). Pre-operative pocket depth was directly correlated with the magnitude of attachment gain as well as the amount of new bone formation in the furcation area. Subjects who maintained good oral hygiene and who had minimal gingival inflammation throughout the study demonstrated consistently better regenerative response.(ABSTRACT TRUNCATED AT 250 WORDS)

The purpose of the present study was to evaluate the effect of anti-infective therapy on the success of periodontal regeneration in mandibular Class II furcation defects. Eighteen patients with mandibular bilateral Class II furcation defects were enrolled. Following an initial hygienic phase, guided tissue regeneration (GTR) was performed using an expanded polytetrafluoroethylene (e-PTFE) membrane barrier. The area was surgically exposed, thoroughly root planed, and irrigated with either tetracycline (100 mg/ml) or 0.9% saline. Post-operative care included systemic tetracycline (250 mg q.i.d.) and chlorhexidine 0.12% mouthwash twice daily. Patients were maintained on a prophylaxis schedule of every 2 weeks for the first 3 months, and monthly thereafter. Clinical parameters of probing depth (PD), probing attachment level - vertical (PAL-v), probing attachment level - horizontal (PAL-h), and target periodontal pathogens were monitored at baseline and quarterly for one year. An overall improvement in all clinical parameters was observed in both groups: probing reduction (3.1 mm), PAL-h gain (2.3 mm), and PAL-v gain (1.2 mm) were all statistically significant compared to baseline measurements. Vertical measurements were performed parallel to the long axis of the tooth with no attempt to angulate the probe into the furcation. There was no significant difference in sites receiving tetracycline. A strong positive correlation was noted between initial PD and pocket reduction (r = 0.77, P < 0.0001) and between initial PD and PAL-h gain (r = 0.54) and PAL-v gain (r = 0.45) suggesting that initial probing depth might be used to assess the regenerative potential of a given site.(ABSTRACT TRUNCATED AT 250 WORDS)

A great deal of controversy has existed in the periodontal literature as to whether the site or the subject should be the unit of analysis. Using the site as the unit of analysis assumes that observations of sites within the same subject are independent and ignores between subject variation. The purpose of this report is to evaluate the influence that the unit of analysis has on estimating the number of necessary site specific bacterial samples from each subject. The number of bacterial samples per subject was defined as the number of samples that would insure a clinician at a 95% confidence level that, if the bacteria were present in a subject, it would be discovered. From two data sets in which 20 to 30 bacterial samples were taken from each subject and data generated from a simulation, appropriate within-subject sample size was determined. In one data set the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, and Prevotella intermedia was determined by indirect immunofluorescence. In the other data set the presence of A. actinomycetemcomitans, P. gingivalis, and P. intermedia was determined using DNA probes. Results of this study demonstrate that there is a large between subject variation in site specific bacterial prevalence, as indicated by an elevated intraclass correlation. Simulated data in this report demonstrated that the number of necessary bacterial samples per subject increased with increasing values of intraclass correlation. The number of necessary within subject samples also increased with decreasing prevalence rate. For A. actinomycetemcomitans, which had a low prevalence rate (0.11 to 0.18), the number of necessary samples per subject was very high (31 to 35).(ABSTRACT TRUNCATED AT 250 WORDS)

The association between specific plaque microorganisms and periodontal diseases has been the subject of much recent interest due to its potential importance in the diagnosis and classification of these diseases. In order to optimize microbiological tests in periodontal therapy, it is important to know how many subgingival plaque samples must be assayed from a single patient in order to ascertain infection with a periodontal pathogen. To answer this question the present study assessed the distribution of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, and Prevotella intermedia in multiple subgingival plaque samples. The samples were quantitatively assessed for specific bacteria by indirect immunofluorescence, a technique previously found to correlate well with cultural assessment of these same organisms. Subgingival plaque from the mesial pockets/sulci of all teeth except third molars was sampled in 12 patients with adult periodontitis, 22 to 28 sites/patient for a total of 315 samples. These patients demonstrated an average mesial probing depth and loss of attachment of 3.7 +/- 1.2 mm and 3.1 +/- 1.5 mm, respectively (mean +/- SD). P. gingivalis, P. intermedia, and B. forsythus were demonstrated in one or more sites from all patients, while A. actinomycetemcomitans was found in one or more sites in 8 of 12 patients. The proportion of positive sites per subject varied, but it was, on average, similar for the 3 black-pigmented organisms and ranged from 44% to 54%. In contrast, A. actinomycetemcomitans was identified, on average, in only 11.4% of the sites in these same patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Two unique forms of periodontal disease, HIV-gingivitis and HIV-periodontitis, have been described in patients with Acquired Immunodeficiency Syndrome (AIDS). In order to determine the bacterial species associated with periodontitis in AIDS patients, the predominant cultivable microflora was examined in 21 subgingival plaque samples from 11 AIDS patients with periodontitis. The presence of putative periodontal pathogens including Actinobacillus actinomycetemcomitans, Bacteroides intermedius, Porphyromonas gingivalis (formerly B. gingivalis), and Wolinella recta was examined by immunofluorescence in 128 subgingival dental plaque samples from 50 AIDS patients including 32 patients with periodontitis. Of 666 bacterial strains isolated from the 21 subgingival plaque samples, Streptococcus sanguis II was the most frequently recovered species comprising 18.5% of the total number of isolates followed by Lactobacillus acidophilus (12.2%), Porphyromonas gingivalis (12%), Fusobacterium nucleatum (11.4%), Staphylococcus epidermidis (8.7%), Actinomyces naeslundii (7.5%), and Actinomyces viscosus (4.7%). Fusobacterium nucleatum was the most prevalent species and was found in 76% of the sites and 91% of the patients. Enteric species including Enterococcus avium and Enterococcus faecalis, Clostridium clostridiiforme and Clostridium difficle as well as Klebsiella pneumoniae also were recovered. Immunofluorescence assays detected similar carriage rates of A. actinomycetemcomitans, B. intermedius, and P. gingivalis in both gingivitis patients and periodontitis patients, while four times more periodontitis patients demonstrated W. recta. Subgingival yeast was a frequent finding in these AIDS patients, present in 62% of the subjects and 55% of the sites. This study indicates that subgingival plaque in AIDS patients with periodontitis can harbor high proportions of the same periodontal pathogens as are associated with periodontitis in non-HIV infected subjects as well as high proportions of opportunistic pathogens.

Research over the past decade has identified many of the microorganisms involved in the etiology of human periodontitis such as Actinobacillus actinomycetemcomitans. Efforts are now directed toward defining these species' role in the pathogenic process. Since microbial colonization of host tissues is a key first step in developing a bacterial infection, determining the source of the periodontal pathogens and their route of transmission is likely to be crucial in formulating preventive strategies. Recently, a technique from molecular biology, restriction endonuclease analysis, has been used to track bacterial infections. In the present study, this method was used to investigate the epidemiology of A. actinomycetemcomitans infection. One hundred twenty-four human subgingival plaque isolates of A. actinomycetemcomitans were examined including bacterial strains from the United States, Korea, and Norway as well as 15 strains from cynomolgus (Macaca fascicularis) and spider monkeys (Macaca iris) and 4 reference strains. The genomic DNA from each strain was purified, digested with each of 16 restriction endonucleases, and the DNA digests were resolved by electrophoresis. The resulting patterns of DNA fragments were compared and also correlated with the A. actinomycetemcomitans serotype determined using serotype-specific antisera in immunofluorescence. Human isolates of A. actinomycetemcomitans even from disparate geographic sources showed little diversity by restriction endonuclease analysis. Three major restriction patterns were found. Restriction pattern I was common to all 20 of the serotype a isolates, restriction pattern II was associated with 58% of the 73 serotype b isolates examined, while restriction pattern III was associated with the remaining serotype b strains and with all 15 of the serotype c strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinobacillus actinomycetemcomitans leukotoxin is thought to be an important virulence factor in the pathogenesis of localized juvenile and other forms of early-onset periodontitis. Some highly leukotoxic A. actinomycetemcomitans strains produce 10 to 20 times more leukotoxin than other minimally leukotoxic strains. The distribution, clonality, and intrafamilial transmission of highly leukotoxic A. actinomycetemcomitans were examined in order to determine the importance of leukotoxin in the pathogenesis of periodontitis.The polymerase chain reaction (PCR) was used to differentiate highly leukotoxic from minimally leukotoxic strains in examining 1,023 fresh A. actinomycetemcomitans isolates and strains from our culture collection. These were obtained from 146 subjects including 71 with localized juvenile periodontitis (LJP), 4 with early-onset periodontitis, 11 with post-localized juvenile periodontitis, 41 with adult periodontitis, and 19 periodontally normal subjects. The arbitrarily primed polymerase chain reaction (AP-PCR) analysis of 30 oral isolates from each of 25 subjects was used to determine the intraoral distribution of A. actinomycetemcomitans clones. AP-PCR was also used to examine the transmission of A. actinomycetemcomitans in 30 members of 6 families. The clonality of 41 highly leukotoxic A. actinomycetemcomitans strains was evaluated by both AP-PCR and ribotyping.Highly leukotoxic A. actinomycetemcomitans was found only in subjects with localized juvenile and early-onset periodontitis. Fifty-five percent of the LJP subjects harbored highly leukotoxic A. actinomycetemcomitans isolates. Seventy-three percent of the A. actinomycetemcomitans isolates in these subjects were highly leukotoxic. Highly leukotoxic A. actinomycetemcomitans infected younger subjects (mean age 13.95 years, range 5 to 28 years) than minimally leukotoxic (mean age 35.47 years, range 6 to 65 years). Most subjects were infected with only one A. actinomycetemcomitans genotype. However, PCR of whole dental plaques and subsequent analysis of up to 130 individual oral isolates suggested a possible shift in A. actinomycetemcomitans over time in that a few subjects harbored both highly leukotoxic and minimally leukotoxic strains. AP-PCR analysis was consistent with intrafamilial A. actinomycetemcomitans transmission. Ribotyping and AP-PCR analysis confirmed a previous report that highly leukotoxic A. actinomycetemcomitans consists of a single clonal type.This study suggests that localized juvenile and other forms of Actinobacillus-associated periodontitis are primarily associated with the highly leukotoxic clone of A. actinomycetemcomitans.

Diabetics and smokers are two patient groups at high risk for periodontal disease who also exhibit impaired wound healing and, therefore, constitute two different groups in whom the relationship between host-parasite interaction, outcome of periodontal therapy, and systemic factors is best represented. The results of two independent clinical trials involving treatment of periodontal disease in diabetics and smokers are presented. A new treatment regimen-for the management of periodontal disease associated with diabetes mellitus is proposed. This treatment approach incorporates both antimicrobial agents and pharmacological modulation of the host response. Elimination of periodontal infection and reduction of periodontal inflammation in diabetic patients resulted in a significant short-term reduction in the concentration of glycosylated hemoglobin (HbA1c ). Control of chronic infections and modulation of the host response offer a new therapeutic approach in the management of patients with both diabetes and periodontal disease. The effect of smoking on periodontal healing is also discussed. The clinical and microbiological response of smokers to non-surgical periodontal therapy is compared to non-smokers. In addition, possible mechanisms whereby diabetes mellitus and cigarette smoking increase the severity of periodontal disease are discussed. J Periodontol 1996;67:1094-1102.

Cigarette smoking has been found to increase the risk for periodontitis. The present study examined the association between cigarette smoking and subgingival infection with periodontal pathogens to determine if smokers are more likely to be infected with certain periodontal pathogens than non-smokers. Self-reported data on 1,426 subjects, aged 25 to 74, from the Erie County Study were obtained including data on 798 subjects who were current or former smokers. Mean clinical attachment loss was used to estimate the severity of periodontal destruction. Subgingival infection with target periodontal pathogens was determined by indirect immunofluorescence microscopy. Smokers harbored significantly higher levels and were at significantly greater risk of infection with Bacteroides forsythus than non-smokers. Adjusting for disease severity, the risk of subgingival infection with B. forsythus in current smokers was 2.3 times that of former smokers or non-smokers. The relative risk of B. forsythus infection also increased 1.18 times for every category of smoking as the amount of smoking measured in packyears increased from very light to heavy. Adjusting for disease severity, Porphyromonas gingivalis was also more likely to subgingivally infect smokers than non-smokers; however, there was not a significantly higher relative risk for infection with this bacterium. The data from this study indicate that cigarette smoking increases the likelihood of subgingival infection with certain periodontal pathogens. This may partly explain the increased risk for periodontitis seen in smokers. J Periodontol 1996;67:1050-1054.

The analytical performance of a membrane-based immunoassay for the simultaneous detection and differentiation of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia (including Prevotella nigrescens) was investigated. Positive reactions were observed for 71 of 71 reference strains and recent oral isolates of A. actinomycetemcomitans, P. gingivalis, and P. intermedia. No cross-reactivity was observed with 39 other common oral and environmental species. The specificity of the test was unaffected by the presence of potential oral interferents including whole blood, white blood cells, mucin, saliva, toothpastes, and oral rinses. A proficiency test by dental professionals using a standardized set of unknown simulated samples yielded a sensitivity of 97% (116/120) and a 100% specificity (240/ 240). An additional group including dental professionals and high school students was shown to be 99% proficient (1385/1397) in distinguishing proper from improper test function when processing control samples with normal test devices and devices with simulated error conditions. Comparisons to a culture standard for 104 subgingival plaque samples collected from 26 adult periodontitis patients yielded > 98% specificity for each of the test bacteria. In addition, the detection threshold for the test was determined to be equivalent to 10(4) cultivable test bacteria when compared to the culture standard. The data indicate that this membrane immunoassay is a valid and easy-to-use method for the detection of A. actinomycetemcomitans, P. gingivalis, and P. intermedia in subgingival plaque, at levels above the detection threshold of the test.

Periodontal status was evaluated in two cohorts participating in a study of the natural history of human immunodeficiency virus (HIV) infection. One cohort consisted of 77 seropositive and 44 seronegative homosexual men, and the other cohort was comprised of 44 seropositive and 39 seronegative parenteral drug users (PDU). No differences were observed between seropositive and seronegative individuals within a cohort in terms of clinical periodontal parameters (percent of sites with > or = 4 mm probing depth, percent of sites exhibiting bleeding on probing, mean oral hygiene index). The PDU displayed more existing periodontal disease than the homosexual men. Periodontal disease in the seropositive individuals in both cohorts was not strictly related to the number of CD4+ lymphocytes. Linear gingival erythema (LGE), defined as an erythematous band of at least 2 mm extending between adjacent papilla, was observed in all 4 groups. Seropositive homosexual men displayed more LGE than seronegative homosexual men (16.6% vs. 11.4%) and seronegative PDU displayed more LGE than seropositive PDU (38.5% vs. 29.5%), but neither difference was significant. LGE tended to be related to reduced numbers of CD4+ lymphocytes, but this relationship did not reach statistical significance. A statistically-significant relationship was found between the presence of intraoral candidiasis and LGE in seropositive homosexual men: 42.9% of these subjects with candidiasis had LGE, while only 12.7% of the subjects without candidiasis had LGE (P < .05). For the seropositive PDU, 35.3% of the individuals with candidiasis had LGE and 25.9% of the subjects without candidiasis displayed LGE, but the difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

The prevalence and genotype distribution of Actinobacillus actinomycetemcomitans strains in families where at least one adult family member (proband) suffered from periodontal disease was investigated to better understand how this periodontal organism is acquired or transmitted. Fifteen probands with severe (established) periodontal disease (EPD) and their 46 immediate family members were sampled for A. actinomycetemcomitans. Among the 15 families, 10 contained at least one additional family member colonized with oral A. actinomycetemcomitans. Genomic DNA from 3 subgingival A. actinomycetemcomitans strains from each of the 10 probands and their 17 family members were amplified and characterized by the polymerase chain reaction (PCR) using a single arbitrary primer known to distinguish A. actinomycetemcomitans strains. The PCR products from each strain were separated by electrophoresis on a 1% submarine agarose gel containing ethidium bromide and visualized by UV light transillumination. The amplification products migrated to form readily distinguishable bands and, since the banding patterns were characteristic of strains of A. actinomycetemcomitans, these patterns were called "amplitypes." The culture studies showed that 51% of all patients suffering from EPD carried oral A. actinomycetemcomitans. Moreover, 50% of their spouses and 30% of their children harbored the bacterium. Comparison of the PCR-generated amplitypes showed that 26 out of 27 individuals had strains exhibiting a single amplitype of A. actinomycetemcomitans, the 27th being colonized by 2 different amplitypes. They also showed that in 6 out of 7 families, the husband and wife did not harbor the same A. actinomycetemcomitans amplitype. Furthermore, most often children carried an an amplitype identical to one of the parents.(ABSTRACT TRUNCATED AT 250 WORDS)

In a random sample of subgingival dental plaque samples from 375 blacks and 300 whites aged 65 and older, immunofluorescence assays for 3 target pathogens including Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia, and BANA enzyme analysis were carried out. Blacks had significantly greater proportions of P. gingivalis and P. intermedia in their subgingival plaque and had significantly higher BANA scores. These assay results were investigated for concordance with each other and with 2 cariogenic salivary bacteria, Streptococcus mutans and lactobacilli. In general for both races, the periodontal pathogens were more likely to occur in combination with each other than with either S. mutans or lactobacilli. P. gingivalis and P. intermedia were more frequently associated with each other than with A. actinomycetemcomitans. There was a significant negative concordance between BANA and A. actinomycetemcomitans in whites and a significant positive concordance between BANA and P. intermedia in blacks.

The objective of The Present study was to define criteria for the diagnosis of "established periodontitis." This term will define subjects who have demonstrated clinical attachment loss, and as such can be considered to have periodontitis. Using these criteria, healthy and established periodontitis subjects were compared with respect to gender, race, and age. Five hundred and eight subjects including 248 females and 260 males between the ages of 25 to 73 (mean 44.6 years), were examined in this study. The clinical examination included: plaque assessment index (PAI); gingival assessment index (GAI); probing pocket depth (PPD); and clinical attachment level (CAL). The mean and frequency distribution of these parameters were analyzed by age and gender. CAL (mean 2.12 mm) showed constant and significant increases with age, ranging from a mean of 1.63 mm in subjects 25 to 34 years of age to a mean of 2.65 mm in subjects 65 to 74 years of age. Males exhibited higher mean values than females for all the measured parameters, which were statistically significant for PAI, PPD, and CAL. The frequency distribution of subjects with PPD and CAL beyond certain threshold levels showed an exponential decline and was correlated to both the severity of the most involved site as well as the number of sites beyond threshold levels. The clinical entity of "established periodontitis" is suggested based on the presence of CAL greater than or equal to 6 mm in 2 or more teeth and one or more sites with PPD greater than or equal to 5 mm. In the present study, 30.5% of the subjects fell into this category.(ABSTRACT TRUNCATED AT 250 WORDS)

The prevalence of people and sites with attachment loss, pocket depth, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Porphyromonas gingivalis are described for a random sample of 366 black and 297 white community-dwelling adults, aged 65 or over, residing in five counties in North Carolina. In addition, relationships between sites harboring these microorganisms and loss of attachment (LA) and pocket depth (PD) are presented in a manner that considers the lack of independence of sites within each person. Pocket depths and recession were measured on all teeth by trained examiners during household visits. Immunofluorescent assays for A. actinomycetecomitans, P. intermedia, and P. gingivalis were conducted on subgingival plaque samples obtained from the mesiobuccal aspect of the four first molar teeth using paper points. The prevalences of A. actinomycetemcomitans, P. intermedia, and P. gingivalis were greater in blacks than in whites. The most striking difference was seen for P. gingivalis, which was found in 38.8% of blacks and 9.4% of whites. Similar relationships were found when the percent of sites with these organisms were assessed. Blacks with P. gingivalis or P. intermedia had a higher prevalence of sites with LA greater than or equal to 7 mm as compared to blacks not infected with P. gingivalis or P. intermedia. The same was true for whites. Similar relationships between P. gingivalis or P. intermedia and PD greater than or equal to 6 mm were found for both blacks and whites.(ABSTRACT TRUNCATED AT 250 WORDS)

The purpose of this study was to determine the prevalence of Actinobacillus actinomycetemcomitans (Aa) in individuals from families where at least one individual has an early onset form of periodontitis. Twenty-three families with 73 subjects were evaluated in this study. Forty-seven early onset periodontitis subjects outside the 23 families were also studied. Prevalence of detection of Aa in family members ranged from 49% to 66% among groups constituted by clinical findings indicative of no loss of attachment, adult periodontitis, generalized severe juvenile periodontitis, or localized juvenile periodontitis. Whether the data were analyzed by subject or by site, no statistical differences could be found in prevalence (proportion of positive samples) among those clinical groups. The only significant difference was that localized juvenile periodontitis subjects had higher concentrations of Aa in their Aa-positive sites than did the other clinical groups. The prevalence of Aa-positive sites in subjects without attachment loss, but who are members of families in which early onset periodontitis is represented, was much higher than in other reports where periodontally healthy subjects were not related to early onset periodontitis cases. This suggests that Aa may be transmitted among members of families in which one or more members has an early onset form of periodontitis.

Recent evidence suggests that dental plaque is not a homogeneous bacterial mass but, on the contrary, specific bacterial morphotypes and species may be preferentially located within certain microenvironments. The aim of the present study was to develop combined gold immunolabeling and scanning electron microscopic (SEM) techniques for the identification of periodontal pathogens in subgingival dental plaque and on the root surfaces of extracted teeth. Suspensions of pure A. actinomycetemcomitans cultures or suspensions of A. actinomycetemcomitans mixed together with other oral bacteria were prepared, labeled with goat anti-rabbit IgG conjugated with 5 nm or 40 nm colloidal gold particles, and observed by SEM using both secondary and back-scattered imaging. Scanning electron microscopy demonstrated that the A. actinomycetemcomitans bacterial cell surface was specifically labelled. There was no cross-reaction with any of the other bacterial morphotypes. Only the labeled A. actinomycetemcomitans were visible in mixtures examined by back-scattered imaging scanning electron microscopy. The combined techniques of gold immunolabeling and SEM may, therefore, be useful in identifying A. actinomycetemcomitans in subgingival plaque samples and on the root surfaces of extracted teeth as well as in studies of bacterial ecology in dental plaque, in general.