The opdB locus encodes the trypsin-like peptidase activity of Treponema denticola. (1/19)

High levels of Treponema denticola in subgingival dental plaque are associated with severe periodontal disease. T. denticola, along with Porphyromonas gingivalis and Bacteroides forsythus, are the only cultivatable oral microorganisms that produce significant amounts of "trypsin-like" peptidase activity. The ability of subgingival plaque to hydrolyze N-alpha-benzoyl-DL-arginine-2-naphthylamide (BANA) is associated with high levels of one or more of these organisms. The purpose of this study was to identify the gene encoding trypsin-like activity in T. denticola and thus facilitate molecular-level studies of its potential role in disease. Using published peptide sequences of a T. denticola surface-associated oligopeptidase with BANA-hydrolyzing activity, we identified the gene, designated opdB, in an apparently noncoding region of the T. denticola genome unannotated contigs (11/2000; http://www.tigr.org). The opdB gene begins with a TTG start codon and encodes a 685-residue peptide with high homology to the oligopeptidase B family in prokaryotes and eukaryotes. An isogenic T. denticola opdB mutant was constructed by allelic replacement mutagenesis using an ermF/AM gene cassette. The mutant lacked BANA-hydrolyzing activity and had a slightly slower growth rate than the parent strain. This mutant will be used in future studies of interactions of T. denticola with host cells and tissue.  (+info)

Comparison of the benzoyl-DL-arginine-naphthylamide (BANA) test, DNA probes, and immunological reagents for ability to detect anaerobic periodontal infections due to Porphyromonas gingivalis, Treponema denticola, and Bacteroides forsythus. (2/19)

Most forms of periodontal disease are associated with the presence or overgrowth of anaerobic species that could include Treponema denticola, Porphyromonas gingivalis, and Bacteroides forsythus among others. These three organisms are among the few cultivable plaque species that can hydrolyze the synthetic trypsin substrate benzoyl-DL-arginine-naphthylamide (BANA). In turn, BANA hydrolysis by the plaque can be associated with periodontal morbidity and with the presence of these three BANA-positive organisms in the plaque. In this investigation, the results of the BANA test, which simultaneously detects one or more of these organisms, were compared with the detection of these organisms by (i) highly specific antibodies to P. gingivalis, T. denticola, and B. forsythus; (ii) whole genomic DNA probes to P. gingivalis and T. denticola; and (iii) culturing or microscopic procedures. The BANA test, the DNA probes, and an enzyme-linked immunosorbent assay or an indirect immunofluorescence assay procedure exhibited high sensitivities, i.e., 90 ot 96%, and high accuracies, i.e., 83 to 92%, in their ability to detect combinations of these organisms in over 200 subgingival plaque samples taken from the most periodontally diseased sites in 67 patients. This indicated that if P. gingivalis, T. denticola, and B. forsythus are appropriate marker organisms for an anaerobic periodontal infection, then the three detection methods are equally accurate in their ability to diagnose this infection. The same statement could not be made for the culturing approach, where accuracies of 50 to 62% were observed.  (+info)

A closer look at diagnosis in clinical dental practice: part 4. Effectiveness of nonradiographic diagnostic procedures and devices in dental practice. (3/19)

This article, the fourth in a series, examines nonradiographic procedures and devices such as standard clinical and visual examination, apex locators, vitality testers and colour shade guides in light of the tools described in the first 2 articles in the series. A variety of nonradiographic indices and scales are used in detecting periodontal disease and monitoring and assessing its treatment. The reliability of these diagnostic procedures directly affects treatment success, decisions to initiate more aggressive clinical interventions, and the ability to make an informed prognosis about the course of the disease. However, in many instances, the dependability of the measurements remains to be established.  (+info)

Detection and measurement of oral malodour in periodontitis patients. (4/19)

BACKGROUND & OBJECTIVES: Malodour has been correlated with the concentration of volatile sulphur compounds produced in the oral cavity by metabolic activity of bacteria colonizing the periodontal sites and the dorsum of the tongue. The aim of this study was to detect malodour in mouth air organoleptically and using a portable sulphide monitor and to correlate it with the clinical parameters, halitosis linked toxins and BANA, using tongue and subgingival plaque samples. The halitosis grading is also correlated with the microbial colonies of the subgingival plaque sample. METHODS: 20 patients with chronic periodontitis with 5-7 mm pocket depth, radiographic evidence of bone loss and presence of oral malodour participated in this study. Assessment of mouth air was done organoleptically and by using a portable sulphide monitor. The clinical parameter, plaque index (PI), gingival index (GI), gingival bleeding index (BI), were obtained from all the areas. Samples for BANA and to detect halitosis linked toxins were taken from the dorsal surface of the tongue and periodontal pockets ranging 5-7 mm. Halitosis related microbial colonies were identified using anaerobic culturing from the subgingival plaque. RESULTS: The scores of PI, GI, BI and sample that tested positive for halitosis linked toxins and with the halitosis grading were not significant. The presence of tongue coating and the halitosis grading and toxin levels were significant. BANA has shown to be non contributory due to technical problems. Anaerobic culture has shown to identify Streptococcus, Bacteroides, Fusobacterium, Porphyromonas and Prevotella colonies. INTERPRETATION & CONCLUSION: The results confirmed that there was no correlation between the clinical parameters, halitosis linked toxins and halitosis grading. The microbial colonies have shown to correlate with the presence of oral malodour.  (+info)

Effect of adjunctive systemic azithromycin with periodontal surgery in the treatment of chronic periodontitis in smokers: a pilot study. (5/19)

BACKGROUND: Along with conventional surgical therapy, systemic antibiotics may provide more effective treatment in smokers by targeting tissue-invasive bacteria. The aim of this randomized, placebo-controlled, double-masked clinical trial was to evaluate the adjunctive effects of systemic azithromycin (AZM) in combination with periodontal pocket reduction surgery in the treatment of chronic periodontitis in smokers. METHODS: Thirty patients with a greater than one pack/day smoking habit and generalized moderate to severe chronic periodontitis were randomized to the test (surgery plus 3 days of AZM, 500 mg) or control group (surgery plus 3 days of placebo). Full-mouth probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival index (GI), plaque index, and wound healing indices (WHI) were assessed at baseline and at 2 weeks and 1, 3, and 6 months following surgical intervention. Plaque and gingival crevicular fluid were collected for trypsin-like enzyme activity (benzoyl-dl-arginine naphthylamine) and bone biomarker (crosslinked telopeptide of type I collagen [ICTP]) analyses, respectively, at baseline, 2 weeks, and 1, 3, and 6 months. RESULTS: Surgical treatment of moderate (PD = 4 to 6 mm) and deep (PD > 6 mm) pockets significantly improved clinical parameters of treated and untreated teeth (CAL gain, PD reduction, and reduction of BOP). The additional use of AZM did not enhance this improvement nor did it promote reduction of ICTP levels. Compared to the control group, the test group had significantly better WHI scores at 1 month, significantly less GI at 2 weeks, and sustained reductions of red-complex bacteria with trypsin-like enzyme activity at 3 months. For non-surgery teeth, only the test group showed significant gains in overall CAL compared to baseline. CONCLUSIONS: The findings of this pilot study demonstrated that in heavy smokers, adjunctive systemic AZM in combination with pocket reduction surgery did not significantly enhance PD reduction or CAL gain. However, the clinical value of adjunctive AZM may be appreciated by more rapid wound healing, less short-term gingival inflammation, and sustained reductions of periopathogenic bacteria. More expanded studies are recommended to better determine the clinical effects of adjunctive AZM in patients who smoke.  (+info)

A retrospective clinical, radiographic and microbiological study of periodontal conditions of teeth with and without crowns. (6/19)

The aim of this study was to evaluate retrospectively the periodontal conditions of teeth with fixed crowns that had been in place from 3 to 5 years before the study was conducted. Forty individuals were recalled for a follow-up visit. Full-mouth clinical examinations were carried out and Visible Plaque Index (VPI), Gingival Bleeding Index (GBI), Probing Pocket Depth (PPD), and clinical attachment level (CAL) were assessed in 6 sites per tooth. Parallel radiographs were also taken and blindly analyzed by a digital caliper (distance between the apex and the bone crest). BANA tests were performed. A contra-lateral sound tooth was considered the control. Mean values were obtained and Wilcoxon and paired sample t tests were used to compare the test and control sites. Crowns had a mean VPI value of 30.42% as compared to 49.17% for sound teeth. The GBI was 33.33% and 26.25% for test and control teeth respectively. Assessment of PPD revealed values of 2.30 and 2.14 mm, and assessment of CAL revealed averages of 2.02 and 1.89 mm for test and control teeth respectively. The mean values for radiographic distances were 12.73 and 13.67 mm, and for the BANA test, 67.50 and 50.00 for sound and crowned teeth, respectively. Statistically significant differences were observed for all parameters except for CAL and for the BANA test. It may be concluded that, with the methods used in the present study, crowns may be associated with more signs of inflammation, however not with periodontal breakdown.  (+info)

Community periodontal index of treatment needs index: an indicator of anaerobic periodontal infection. (7/19)

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The ability of the BANA Test to detect different levels of P. gingivalis, T. denticola and T. forsythia. (8/19)

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