Randomized Trial to Test a Chemo-Mechanical Antiplaque Regimen as Adjunct to Periodontal Therapy.

BACKGROUND: The control of dental biofilm regrowth after nonsurgical periodontal therapy is associated with better clinical outcomes. However, many patients have difficulty achieving optimal plaque control. Subjects with diabetes, in which immune and wound-healing responses are typically impaired, may benefit from intensive antiplaque control regimens after scaling and root planing (SRP). OBJECTIVES: This study aimed to evaluate the effects of an intensive, at-home, chemical, and mechanical antiplaque regimen as an adjunct to SRP for the treatment of moderate to severe periodontitis. A secondary objective was to compare responses in subjects with type 2 diabetes and nondiabetics. METHODS: This was a 6-mo, single-center, parallel-group, randomized trial. The test group received SRP and oral hygiene instructions, and subjects were instructed to use a 0.12% chlorhexidine gluconate mouthrinse twice a day for 3 mo and utilize rubber interproximal bristle cleaners twice a day for 6 mo. The control group received SRP and oral hygiene instructions. The main outcome was change in mean probing depth (PD) from baseline to 6 mo. Secondary outcomes included change in sites with deep PDs, mean clinical attachment level, bleeding on probing, plaque index, hemoglobin A1C, fasting blood glucose, C-reactive protein, and taste assessment. This study was registered at ClinicalTrials.gov as NCT04830969. RESULTS: In total, 114 subjects were randomized to either treatment. Eighty-six subjects completed the trial with no missing visits. Neither an intention-to-treat nor a per-protocol analysis showed statistically significant differences between treatment groups in mean PD at 6 mo. In a subgroup analysis, subjects with diabetes in the test group showed a statistically significant greater reduction in mean PD at 6 mo when compared to subjects with diabetes receiving the control treatment (Δ = 0.15, P = 0.04), while there were no differences within nondiabetics (Δ = 0.02, P = 0.75). CONCLUSION: Outcomes in subjects with diabetes may be improved by chemo-mechanical antiplaque measures after nonsurgical periodontal therapy. KNOWLEDGE TRANSFER STATEMENT: This study suggests diabetic subjects may benefit from an intensive, at-home, chemical, and mechanical antiplaque regimen to improve nonsurgical periodontal therapy outcomes.

Antimicrobial efficacy of 0·05% cetylpyridinium chloride mouthrinses.

UNLABELLED: This study evaluated the antimicrobial activity of two commercially available 0·05% cetylpyridinium chloride (CPC) mouthrinses with or without alcohol and examined its antimicrobial activity on oral bacterial species including fresh clinical isolates compared to a chlorhexidine mouthrinse and a control fluoride mouthrinse without CPC. Two different approaches were used to evaluate antimicrobial activity. First, the minimum inhibitory concentration (MIC) was determined for each mouthrinse against a panel of 25 micro-organisms including species associated with dental caries, gingivitis and periodontitis. Second, supragingival dental plaque obtained from 15 adults was incubated with the four mouthrinses to evaluate antimicrobial activity on micro-organisms in oral biofilms. Both CPC mouthrinses exhibited lower MIC's, that is, greater antimicrobial activity, against oral Gram-negative bacteria especially periodontal pathogens and species implicated in halitosis such as Aggregatibacter actinomycemcomitans, Campylobacter rectus, Eikenella corrodens, Porphyromonas gingivalis, Prevotella intermedia and Solobacterium moorei than the control mouthrinse. Ex-vivo tests on supragingival plaque micro-organisms demonstrated significantly greater antimicrobial activity by the CPC mouthrinses (>90% killing, P < 0·001) and the chlorhexidine rinse (>98% killing, P < 0·05) compared to the control fluoride mouthrinse. Whilst the chlorhexidine mouthrinse was most effective, mouthrinses containing 0·05% CPC formulated with or without alcohol demonstrated broad-spectrum antimicrobial activity against both laboratory strains and supragingival plaque bacteria compared to a control mouthrinse without CPC. SIGNIFICANCE AND IMPACT OF STUDY: These in vitro and ex-vivo studies provide a biological rationale for previous clinical studies demonstrating the efficacy of CPC mouthrinses in reducing supragingival plaque and plaque-associated gingivitis.

The effect of a microbead dentifrice on microbial load in oral microenvironments.

OBJECTIVES: The human oral cavity contains several microenvironments or ecologic niches. While mechanical plaque control is well known to reduce the number of supragingival dental plaque bacteria, there is little data on antimicrobial effects in other oral ecologic niches. The present study examined the effects of mechanical plaque control using a microbead dentifrice on bacteria colonizing oral ecologic niches. METHODS: Twenty-two adults (aged 18-70years) including nine generalized moderate chronic periodontitis subjects and 13 periodontally healthy subjects having average gingival indices ≥1 and plaque indices ≥1.5 completed a 1week washout phase and refrained from oral hygiene the morning of baseline sample collection. Microbial samples from supragingival dental plaque, buccal mucosa, dorsal surface of the tongue and whole mixed saliva were obtained. Subjects brushed with a microbead dentifrice and, after 10min, sampling was repeated. The number of anaerobic bacteria was determined by culture on non-selective media and transformed to log(10) for statistical analyses. RESULTS: Mechanical plaque control using the microbead dentifrice resulted in statistically significant reductions in bacterial numbers in each ecologic niche (P<0.001). The greatest reduction in the number of viable bacteria occurred in samples taken from the buccal mucosa (97.22%) followed by a 95.22% reduction in supragingival plaque bacteria, a 94.51% reduction in the number of bacteria on the dorsal surface of the tongue and a 91.57% reduction in the number of bacteria in whole mixed saliva. CONCLUSIONS: Mechanical plaque control using a microbead dentifrice reduces microbial load in microenvironments throughout the human oral cavity.

Characterization and prevalence of Solobacterium moorei associated with oral halitosis.

Previous studies suggest that Solobacterium moorei is associated with oral halitosis. In the present study, we examined the prevalence of S. moorei on the dorsal surface of the tongue in 57 adults (21 with and 36 without halitosis) by bacterial culture and direct amplification of nucleic acids. We also examined the S. moorei type strain and four clinical isolates for 16S ribosomal nucleic acid sequence, H(2)S and enzyme production, and antibiotic susceptibility. S. moorei was found on the dorsal surface of the tongue in 100% of the subjects with halitosis and 14% of subjects without halitosis. Infection with S. moorei was correlated with organoleptic measures of halitosis and with volatile sulfur compound levels. Nucleic acid probe detection of S. moorei as a test for halitosis exhibited 100% sensitivity and 86% specificity. The S. moorei type strain and all four clinical isolates showed >98% 16S rDNA sequence similarity, produced H(2)S, demonstrated acid phosphatase, beta-galactosidase, alpha-glucosidase, esterase, leucine arylamidase and naphthol phosphohydrolase enzyme activities, and were sensitive to all antibiotics tested except gentamicin, kanamycin, nalidixic acid and rifampin. This study supports the hypothesis that S. moorei is associated with halitosis.

Media- and method-dependent variations in minimal inhibitory concentrations of antiplaque agents on oral bacteria.

AIMS: To determine minimal inhibitory concentrations (MICs) and the percentage of nonsusceptible bacteria-- those still cultivable above a threshold concentration--in human supragingival dental plaque and saliva for antiplaque/antimicrobial agents including triclosan (TCS) and trichlorocarbanilide (TCC), and a new potential antimicrobial, 2-t-butyl-5-(4-t-butylphenyl)-phenol (DTBBP). METHODS AND RESULTS: Broth and agar dilution-based MIC tests were performed using 28 oral and nonoral bacterial strains representing 17 species. MICs for TCS were lowest and more than 100-fold lower than DTBBP (P < 0.0005) by both methods. MICs for TCS were lower in broth-based tests compared with TCC. The additions of defibrinated blood to agar and horse serum to broth increased MICs--in the case of TCS, 10- to 15-fold. Significantly higher proportions of nonsusceptible plaque and salivary bacteria were recovered from agar media containing DTBBP or TCC compared with TCS (P < 0.05). CONCLUSIONS: TCS is a more effective antimicrobial agent than either TCC or DTBBP as determined by in vitro testing. SIGNIFICANCE AND IMPACT OF THE STUDY: The utility of in vitro testing for antiplaque agents as a predictor of in vivo efficacy is affected by the methods used.

Prevalence of periodontal pathogens in Brazilians with aggressive or chronic periodontitis.

OBJECTIVES: Previous studies suggest differences between geographically and racially distinct populations in the prevalence of periodontopathic bacteria as well as greater periodontal destruction associated with infection by highly leucotoxic Actinobacillus actinomycetemcomitans. The present study examined these hypotheses in Brazilians with aggressive or chronic periodontitis. MATERIALS AND METHODS: Clinical, radiographical, and microbiological assessments were performed on 25 aggressive periodontitis and 178 chronic periodontitis patients including 71 males and 132 females, 15-69 years of age. RESULTS: The prevalence of Porphyromonas gingivalis was similar to that of other South American populations. The prevalence of A. actinomycetemcomitans and its highly leucotoxic subgroup was higher in Brazilians. Highly leucotoxic A. actinomycetemcomitans was more prevalent in aggressive periodontitis (chi2=27.83) and positively associated with deep pockets (>6 mm, chi2=18.26) and young age (<29 years, chi2=18.68). Greater mean attachment loss was found in subjects with highly leucotoxic A. actinomycetemcomitans than in subjects with minimally leucotoxic (p=0.0029) or subjects not infected (p=0.0001). CONCLUSION: These data support the hypothesis of differences between populations in the prevalence of periodontopathic bacteria and of greater attachment loss in sites infected with highly leucotoxic A. actinomycetemcomitans. Detection of highly leucotoxic A. actinomycetemcomitans in children and adolescents may be a useful marker for aggressive periodontitis.

[Detection of periodontal pathogenic microorganisms in atheromatous plaque. Preliminary results]. / Nachweis parodontal pathogener Mikroorganismen in atheromatösen Plaques. Vorläufige Ergebnisse.

INTRODUCTION: Recent studies suggest that chronic infections, including those associated with periodontitis, increase the risk for coronary vascular disease. 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. MATERIALS AND METHODS: To test this hypothesis, 34 human specimens obtained during carotid endarterectomy or bypass procedures were examined by use of specific oligonucleotide primers for Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans and Bacteroides forsythus in polymerase chain reaction (PCR) assays. RESULTS: Twenty (59%) of the 34 specimens tested positive for bacterial 16S rDNA. Subsequent hybridization of the bacterial 16S rDNA positive specimens with species-specific oligonucleotide probes revealed that 32.4% of the 34 atheromas tested positive for at least one of the target periodontal pathogens. Further analysis of the results in the bacterial positive group (n = 20) shows that 55% of the atheromas tested positive for at least one of the target periodontal pathogens. CONCLUSION: These findings indicate that periodontal pathogens are present in atherosclerotic plaques, where they may play a role in the development and progression of atherosclerosis leading to coronary vascular disease and other clinical sequelae.

Molecular cloning of the fur gene from Actinobacillus actinomycetemcomitans.

In several bacterial species, iron availability in host tissues is coordinated with the expression of virulence determinants through the fur gene product. Initial experiments showed that a cloned Escherichia coli fur gene probe hybridized to Southern blots of Actinobacillus actinomycetemcomitans strain JP2 (serotype b) chromosomal DNA. The A. actinomycetemcomitans fur gene was then cloned utilizing partial functional complementation of the fur mutant in E. coli strain H1780. Analysis of the cloned DNA sequence revealed a 438-bp open reading frame with a deduced 146-amino-acid sequence exhibiting 80% identity to Haemophilus influenzae Fur and 62% identity to E. coli Fur. The pUC Aafur gene probe (generated from JP2 serotype b) hybridized to representatives from all five A. actinomycetemcomitans serotypes as well as to two strains derived from monkeys, suggesting that fur is widely distributed in A. actinomycetemcomitans. Open reading frames having >70% identity with the E. coli and H. influenzae flavodoxin and gyrase A genes, respectively, were found. Expression of the A. actinomycetemcomitans fur gene product repressed fiu expression and siderophore production in E. coli. A gel shift assay demonstrated that the expressed A. actinomycetemcomitans Fur protein bound the bacterial fur consensus sequence. Further characterization of the fur gene product in A. actinomycetemcomitans may improve our understanding of its role in the pathogenesis of periodontal disease and may lead to specific therapeutic modalities.

Periodontal infections contribute to elevated systemic C-reactive protein level.

BACKGROUND: 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. METHODS: 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 sites > or =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. RESULTS: 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 CRP > or = 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). CONCLUSIONS: 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.

Identification of periodontal pathogens in atheromatous plaques.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Evidence for the role of highly leukotoxic Actinobacillus actinomycetemcomitans in the pathogenesis of localized juvenile and other forms of early-onset periodontitis.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: This study suggests that localized juvenile and other forms of Actinobacillus-associated periodontitis are primarily associated with the highly leukotoxic clone of A. actinomycetemcomitans.

Rapid chair-side DNA probe assay of Bacteroides forsythus and Porphyromonas gingivalis.

This study compared a rapid, colorimetric DNA probe assay designed to be performed in a dental office within 40 min, with anaerobic culture and indirect immunofluorescence microscopy (IFM) for detection of Bacteroides forsythus and Porphyromonas gingivalis in subgingival plaque samples. The DNA probe assay used the Periodontal Microbial Identification Test (Saigene Corporation, Bothell, Washington, USA). B. forsythus was detected in 46 (52%), 49 (55%) and 39 (44%) of the samples by DNA probe, culture (at levels > or = 10(5)) and IFM, respectively. P. gingivalis was detected in 24 (27%), 18 (20%) and 29 (33%) of the samples by DNA probe, culture (at levels > or = 10(5)) and IFM, respectively. Results from the DNA probe assay were compared to culture. Culture negative, probe positive samples were re-evaluated by IFM, and IFM positive samples were considered positive in "resolved" data. Using resolved data. DNA probe detection sensitivity and specificity values for B. forsythus were 81% and 91% and for P. gingivalis were 80% and 95%, respectively. DNA probe test results were further compared with culture and IFM. For samples negative by both culture and IFM, probe specificity was 92% in 25 B. forsythus samples and 95% in 57 P. gingivalis samples. For samples positive by both reference methods, probe sensitivity was 82% in 27 B. forsythus samples and 73% in 15 P. gingivalis samples. B. forsythus was detected more frequently by culture compared with IFM; the reverse was observed for P. gingivalis. The rapid DNA probe assay for B. forsythus and P. gingivalis was comparable to cultivable and IF analyses.

Efficacy of a triclosan/NaF dentifrice in the control of plaque and gingivitis and concurrent oral microflora monitoring.

PURPOSE: To compare the effect of a dentifrice containing 0.3% triclosan and 1100 ppm fluoride and a control dentifrice containing 1100 ppm fluoride on plaque, gingiva and the oral microflora in a long-term study simulating clinical usage. MATERIALS AND METHODS: 159 subjects entered the clinical study and 80 were randomly selected to participate in the microbiological evaluation. 71 subjects completed the detailed evaluation of the oral microflora after 6 months use. Plaque was collected at baseline, 3 months, and 6 months, and examined by darkfield microscopy, Gram stain, immunofluorescence, and selective and non-selective media. Changes in antimicrobial susceptibilities were determined for the first 6-month period and for 6 months post-therapy for 68 subjects who completed the entire study. Susceptibilities of whole plaque samples and MIC values for two pre-designated common plaque organisms, A. viscosus and V. parvula were performed. RESULTS: Multivariate ANOVA and non-parametric analyses revealed no statistical differences for any factor tested. No detrimental shifts were found in either; (1) the compositional make up of the normal flora, (2) the periodontopathic or cariogenic flora, or (3) the opportunistic flora in either group of dentifrice users. Both treatments resulted in decreases in Gram positive cocci over time. There was a reduction in spirochetes in the triclosan/fluoride group as compared to the control group. No overgrowth in opportunists, periodontal pathogens, or cariogenic flora was found in either group. No increase in the proportion of the whole plaque flora resistant to triclosan was found nor was an increase in the MIC values of either A. viscosus or V. parvula in either group. Overall, there appeared to be a general decrease in plaque bacteria in both groups over the course of the experiment.

Epidemiology and diagnosis of HIV-associated periodontal diseases.

A review of periodontal disease as a manifestation of HIV infection suggests a shift in emphasis over the past 5 years. Initially the focus was on newly described forms of periodontal disease (i.e., HIV-associated gingivitis or linear gingival erythema (LGE); HIV-associated periodontitis or necrotizing ulcerative periodontitis (NUP). While the clinical definition of LGE varies from study to study, an association between LGE and Candida infection has been described. Furthermore, the prevalence of NUP is quite low and this disorder is associated with severe immunosuppression. In contrast, the focus today is on the accelerated rate of chronic adult periodontitis occurring in seropositive patients. While the organisms that characterize adult periodontitis in seronegative individuals are present in subgingival plaque from seropositive individuals, reports suggest that atypical pathogens are also present (i.e., Mycoplasma salivarium, Enterobacter cloacae). Recent studies from our laboratory have identified a novel strain of Clostridium isolated from the subgingival plaque of injecting drug users that has pathologic potential. This organism, however, was found in both seropositive and seronegative individuals in this cohort, suggesting an association with lifestyle rather than serostatus. In addition, data has been published examining the local host response in periodontitis in seropositive individuals. Distinctly elevated levels of IgG in gingival crevicular fluid (GCF) have been observed in seropositive patients. Furthermore, data from our laboratory examining inflammatory mediators in GCF (polymorphonuclear leukocyte lysosomal enzyme beta-glucuronidase and the pro-inflammatory cytokine interleukin-1 beta) suggests an altered response in patients with HIV infection. The alteration manifests as the absence of the expected strong correlation between polymorphonuclear leukocyte activity in the gingival crevice and clinical measures of existing periodontal disease, as well as elevated levels of interleukin-1 beta in sites with deeper probing depths. Therefore, it can be concluded that the progression of periodontal disease in the presence of HIV infection is dependent upon the immunologic competency of the host as well as the local inflammatory response to typical and atypical subgingival microorganisms.

Principles of evaluation of the diagnostic value of subgingival bacteria.

This paper describes steps in the process of evaluating subgingival bacteria assays for the diagnosis of periodontal disease. The first step examines the infectious etiology of periodontal disease in pointing to specific oral bacteria as periodontal pathogens. Second is characterization of the laboratory test to detect and quantitate these pathogens as to sensitivity, specificity, and positive and negative predictive value. Third is the role of the laboratory test in the diagnosis of the different forms of periodontal disease which is related to the current clinical rather than microbiological definition of these diseases. The fourth and most important step is an analysis of the significance of subgingival bacterial tests in clinical decision-making.

Longitudinal study of prognostic factors in established periodontitis patients.

Numerous indicators for disease progression have been described in the last decade. The purpose of this study was to examine, longitudinally, a large battery of clinical, microbiological, and immunological indicators, to try to determine whether the presence of one or a combination of these parameters at baseline, would correlate positively with increased attachment and or bone loss (true prognostic factors). Following initial screening, 79 patients with established periodontitis were monitored longitudinally for one year. Whole mouth clinical measurements, plaque gingival and calculus indices, together with pocket depth and attachment level measurements, were repeated every three months. Full mouth radiographic survey, performed at baseline and 12 months, served to determine changes in crestal bone height using an image enhancement technique. Subgingival plaque samples were taken at baseline and every 3 months. Immunofluorescence assays were performed for the a battery of target microorganisms. Serum and GCF samples for IgG subclasses analysis were obtained at each visit and assayed using ELISA techniques. Likewise blood, samples were also drawn at each visit for a quantitative analysis of serum cotinine level. The overall mean attachment loss (AL) and bone loss (BL) were almost identical (0.159 mm and 0.164 mm, respectively). Individual patients variation was large (-0.733 to +1.004 mm). An overall 6.89% of sites were active; individual patients' means ranged from 0-28.9%. Mean pocket depth (PD) showed minimal change over the study period (-0.033 mm) thus suggesting that most if not all the AL was accompained by concomitant gingival recession. Smokers exhibited greater AL and radiographic BL compared to non-smokers. Likewise, patients' cotinine level showed direct correlation with outcomes of progressive periodontal breakdown. Past severity of periodontal involvement, as reflected in the patients baseline PD, AL and crestal bone height, showed good correlation with longitudinal changes in the periodontium. This correlation was higher for crestal BL as the outcome variable, while somewhat smaller for change in AL as the outcome variable. Bacteroides forsythus (Bf.), Prevotella intermedia (Pi.) and Porphyromonas gingivalis (Pg.) were frequently found in these patients. The presence of these microorganisms at baseline was associated with further disease progression. Subjects with mean baseline pocket depth equal or greater than 3.2 mm were at greater risk for future bone loss 1 year later (O.R. 2.97; C.I. 1.02-8.70). Smokers were at significantly greater risk for further attachment loss when compared to non-smokers (O.R. 5.41; C.I. 1.50-19.5). Subjects that harbored B. forsythus at baseline, were at seven times greater risk for increased pocket depth (O.R. 7.84; C.I.1.74-35.3). In conclusion, past periodontal destruction, smoking habits, Bf., Pg., & Pi. are prognostic factors for further periodontal breakdown. When designing clinical trials, or when evaluating epidemiological data, it is most important to balance for these factors. Also, treatment strategies should attempt to eliminate or modify these factors.

Rapid diagnosis of periodontal infections: findings in AIDS patients.

A small number of bacterial pathogens in the human oral cavity cause the different forms of periodontal disease. Of the approximately two hundred different oral bacterial species, about a dozen have been associated with these diseases including localized juvenile periodontitis, rapidly progressing periodontitis, and adult periodontitis. These species include Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Campylobacter rectus, Porphyromonas gingivalis, and Prevotella intermedia. Several rapid methods have been developed to detect these species in clinical samples. These include immunologic methods such as immunofluorescence, nucleic acid assays such as DNA-DNA hybridization in dot blots and enzyme assays. Immunofluorescence microscopy has been used to determine the prevalence and relative proportions of these pathogens in dental plaque samples from 194 subjects including HIV-infected and uninfected male homosexuals and intravenous drug users.

A microbiological and clinical study of the safety and efficacy of baking-soda dentifrices.

This article reports the results of a study that examined the clinical and microbiological changes associated with regular use of baking-soda dentifrices. Two dentifrice formulations were examined in a 6-month longitudinal study of 101 adult subjects with assessments for plaque, gingival inflammation, and stain at baseline and 3 and 6 months during the active phase of the study, and at 3 months after cessation of product use. One dentifrice contained 52% baking soda and 3% sodium percarbonate (Arm & Hammer PeroxiCare) while the other dentifrice contained 65% baking soda (Arm & Hammer Dental Care). Both dentifrices resulted in statistically significant reductions in dental plaque, gingival inflammation, and stain at all time periods compared to baseline. Dental plaque and buccal soft-tissue samples were obtained for microbiological analysis from a 50-subject subset. Microbiological assays, including bacterial culture, phase-contrast microscopy, and immunofluorescence microscopy, confirmed the safety of both formulations. Beneficial alterations in dental plaque bacteria were noted, including significant reductions in the levels of Actinomyces species. The data from this study indicate that dentifrices containing high levels of baking soda are clinically effective and microbiologically safe.