Multi-center clinical evaluation of a chairside method for detecting certain periodontopathic bacteria in periodontal disease

The effects of incubation length and temperature on the specificity and sensitivity of the BANA (N-benzoyl-DL-arginine-naphthylamide) test

A previous multi-center study examining patients diagnosed as having at least four periodontally diseased teeth showed that when BANA (N-Benzoyl-DL-Arginine-Naphthylamide) hydrolysis by periodontal pathogens such as Treponema denticola, Porphyromonas gingivalis, and Bacteroides forsythus was evaluated versus clinical parameters such as clinical judgment of disease, bleeding on probing, and pocket depth, the sensitivity of the test was 84%, 82%, and 87%, respectively, while the specificity was only 42%, 41%, and 32%, respectively. The purpose of the present investigation was to improve the specificity of the test while retaining a high level of sensitivity in both gingivally healthy and periodontally diseased groups. One hundred forty-nine patients participated in this study providing 3,497 interproximal plaque samples. Gingival health was measured using the papillary bleeding score and this was compared with the presence or absence of detectable trypsin-like activity, as determined by the BANA hydrolysis of interproximal plaque samples, using a commercially-available test. Sensitivity and specificity were measured by varying the incubation time and temperature of the enzymatic assay. Using the correlated binomial model to analyze site-specific data within a patient, the specificity was highest at 35 degrees C and 5 minutes incubation (94%), and lowest at 45 degrees C and 15 minutes incubation (33%). Sensitivity was highest at 45 degrees C or 55 degrees C and 15 minutes incubation (90%) and lowest at 35 degrees C and 5 minutes incubation (47%).(ABSTRACT TRUNCATED AT 250 WORDS)

Role of suspected periodontopathogens in microbiological monitoring of periodontitis

Periodontal disease is the clinical result of a complex interaction between the host and plaque bacteria. Although a specificity to some degree is found for Actinobacillus actinomycetemcomitans in localized juvenile periodontitis (LJP), it has been difficult to obtain evidence for a specific etiological role of the bacteria associated with periodontal disease in adults. What we see is the net result of host-parasite interactions which in an unpredictable moment accumulate and exceed the threshold of tissue integrity. This hypothesis is concomitant with the view of periodontal disease as a polymicrobial infection, predominantly anaerobic, which occurs commonly in the oral cavity or elsewhere in the body. Some micro-organisms (risk markers) occur more frequently than others and may significantly determine the outcome of this host-parasite interaction. Microbiological sampling and analysis seem to be of limited value in risk assessment; however, they can be used as tools in diagnosis in LJP patients and acute infections, and in treatment decision and therapy control in "refractory" patients. Suspected pathogens (risk markers) are Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and some species of spirochetes, while the roles of Prevotella intermedia, Bacteroidesforsythus, Fusobacterium nucleatum, Campylobacter rectus, and Peptostreptococcus micros are more uncertain. The presence of periodontopathogens as well as enterics, Staphylococcus aureus and Candida especially, should be considered in patients with systemic individual disorders--e.g., diabetes mellitus, neutropenia, agranulocytosis, and AIDS--or with implants.

New technologies for the diagnosis of periodontal disease

Historically the initial onset of periodontal disease in an individual was considered slow but continuously progressive over time. It was inferred that an individual would experience progressive destruction of the attachment structures until edentulous. However, several studies in the early 1970s contested the traditional concept of continuous disease progression. These studies suggested that periodontal disease progressed by recurrent acute episodes. In specific individuals, the loss of attachment was faster than the concept of slowly progressing disease. There were also sites in patients that progressed slower (or not at all) than anticipated on the basis of radiographic and clinical history of previous disease progression. These findings clearly indicated the need to explore the nature of periodontal disease progression and to institute a major effort into innovative methods to diagnose periodontal diseases. Dentists and researchers could more effectively prevent and treat periodontal disease and relate pertinent research findings to specific disease initiation and progression.

Spirochaetes in oral infections

Oral spirochaetes, which are small-, medium- or large-sized, include species of the genus Treponema, many of which have not yet been cultured. They are found in root canal infections, pericoronitis, gingivitis and periodontitis, constituting up to 10% of the flora in endodontic abscesses, 30% in acute necrotizing ulcerative gingivitis, and 56% in advanced marginal periodontitis. The strong proteolytic activity of these organisms probably make them causes of infection rather than consequences. Being able to penetrate tissue, they bring their enzymes, metabolic products, and endotoxins, in direct contact with target cells. This may perturb essential functions of host cells and immunoglobulins. Enzyme activities may also help fulfil the complex growth requirements of spirochaetes in vivo. Reaction between infected periodontal tissue and monoclonal antibodies to Treponema pallidum has suggested that uncharacterized pathogen-related oral spirochaetes have surface structures and functions analogue to this well recognized pathogen. This warrants a more intensified search for the role of spirochaetes in oral infections.

Black-pigmented gram-negative anaerobes in periodontitis

Black-pigmented Gram-negative anaerobes have been associated with periodontal disease and tooth loss since they were first isolated by Burdon in 1928. Porphyromonas gingivalis, which is usually not isolated from children, adolescents or adults with no periodontal breakdown, has been recognized as one of the most important periodontopathogens. Its presence is strongly correlated with deep periodontal pockets, which are assumed to be its main habitat. Correlations have been shown also with attachment loss, clinical inflammation and serum antibody levels, indicating an aetiological role in the periodontal disease. Their pathogenicity in animal models resembling periodontal disease is documented. They are frequently isolated from periodontal abscesses. The relationship between Prevotella intermedia and periodontal disease is not clear. It is frequently isolated from advanced periodontitis, often as the only black-pigmented Gram-negative anaerobic species; however, the prevalence in adults with no periodontal breakdown is high. It is found frequently in periodontal abscesses and in acute necrotizing and ulcerative gingivitis. Serogroup I is found predominantly in deep periodontal pockets, whereas all serogroups (I-III) are found in shallow pockets and gingivitis. No conclusive difference in pathogenicity between serogroups has been found. Pr. melaninogenica, Pr. denticola and Pr. loescheii are frequently found in the gingival crevice in preschool children and other age groups with gingivitis, but are seldom found in deep periodontal pockets.

Metronidazole in periodontitis (IV). The effect of patient compliance on treatment parameters

Patient compliance with the unsupervised usage of prescription medication can be poor. In the treatment of periodontal infections with systemic antimicrobial agents, in situations where the efficacy of the antimicrobial agent is being evaluated, non-compliance could underestimate the true efficacy of the agent. Metronidazole is an agent with reported success in the treatment of anaerobic periodontal infections. Metronidazole is particularly effective in vitro against spirochetes, and this efficacy was investigated as a means of measuring patient compliance with metronidazole usage. Patients who had high proportions of spirochetes, i.e., > 20%, in plaques removed from diseased periodontal sites, were given metronidazole (500 mg bid) under supervision. In all individuals who received the metronidazole, there was a significant and rapid decline and/or disappearance of spirochetes from the plaque during the time interval that metronidazole was detectable in the saliva. This observed decline in spirochetes was then used to determine which patients had been compliant in a double-blind clinical trial involving the unsupervised usage of metronidazole. Only 10 of 18 patients (56%) were considered compliant in their usage of metronidazole. These 10 patients experienced a significantly greater benefit from the metronidazole than did the 8 patients who were considered noncompliant, i.e., a reduction of surgical needs of 8.3 teeth per compliant patient versus 3.6 teeth per non-compliant patient. A test for the hydrolysis of the synthetic peptide (BANA) was also able to identify most non-compliant patients. Clinical trials involving the unsupervised usage of systemic medication need to take into account patient non-compliance.

The effect of incubation temperature on the specificity of the BANA (N-benzoyl-DL-arginine-naphthylamide) test

The hydrolysis of BANA by subgingival plaque samples is associated with the presence of either Treponema denticola, Porphyromonas gingivalis, and/or Bacteroides forsythus. A protocol in which pure cultures were incubated for 15 min at 55 degrees C detected about 5 x 10(5) CFU of P. gingivalis and 1 x 10(6) CFU of T. denticola. Clinical studies indicated that the BANA test in this configuration will detect about 10(4) organisms in vivo as compared with the 10(5) to 10(6) organisms found with in vitro grown cells. The BANA test can be made less sensitive by decreasing the time and/or temperature of incubation, which could improve the specificity of the test. In the present study we determined the incubation parameters that would give optimal specificity when the plaque samples were removed from sites of gingival health. Twenty-six approximal plaque samples were taken from each of 90 clinically healthy subjects and incubated with the BANA substrate on PerioScan cards (Oral-B Laboratories) for 5 and 15 min at 35 degrees, 45 degrees, and 55 degrees C. Subjects were randomly assigned to the various temperatures. Wooden toothpicks were inserted interproximally in all sites anterior to distal of the first molars and then each side of the toothpick was wiped onto the PerioScan card. The specificity of the BANA test relative to clinical health was 96% when the cards were incubated for 5 min at 35 degrees C, but decreased to 50-70% when the cards were incubated for 15 min at 35 degrees C or for 5 and 15 min at 45 degrees C and 55 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of metronidazole in the treatment of periodontal diseases

This article discusses the ability of metronidazole to improve periodontal health. Review of the drug's pharmacology and potential side effects indicate that it poses little threat to humans of inducing acute toxicity, mutagenesis, or cancer if used according to recommended dosing regimens. Studies addressing metronidazole utilization in a variety of clinical conditions demonstrate that its routine use does not enhance root planing. However, adjunctive antibiotic therapy may be advantageous in the treatment of sites where effective root planing is precluded due to deep pockets or when anaerobic periodontal infections do not respond to conventional therapy.

A dietary procedure for preventing dental caries in young adults

Significant improvement in the dental caries status of children in the United States has been seen in recent decades. The percentage of children who are free from dental caries, however, rapidly decreases with age. By the time young people enter colleges or universities, only a few are caries free. Colleges and universities are places where the young are simultaneously, and perhaps for the last time, reachable as large cohorts before their lives undergo further "individualization." This makes college age a time that is crucial for channeling information about proper oral health practices by organizing mass-directed strategies for prevention of dental caries. It is now clear that dental caries can effectively be prevented. This calls for placing strong emphasis on dietary behavior and on the use of sugar substitutes as part of the strategy. Scientific evidence also suggests that the addition of small daily quantities of xylitol, a natural carbohydrate sweetener, to the diet of children and young adults causes significant reduction in the incidence of dental caries. On the basis of detailed long-term clinical trials carried out during the past 20 years, it appears that a reduction ranging from 30% to more than 85% in dental caries can be achieved simply by using a few xylitol chewing gums daily over a period of 1 to 3 years. In individual cases, virtually total, long-term protection against caries has been observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Recent advances in periodontal diagnosis and treatment: exploring new treatment alternatives

A better understanding of the etiology and pathogenesis of periodontal diseases provides clinicians and researchers with a number of new diagnostic techniques and treatment alternatives. These new developments may also offer the clinician additional information for treatment planning.

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

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

Design issues specific to studies of periodontitis

Guidelines for clinical trials demonstrating equivalence or superiority for treatments for periodontitis are badly needed because of the great variety of drugs, agents, and devices now being developed. This paper focuses on three design issues. These are primary outcome variables and their measurement, disease-active vs disease-inactive sites and patients, and study duration. Determinants for selection of outcome variables include the biologic events to be observed, changes that are specific for periodontitis, and methods chosen to detect those changes. The primary outcome variables specific for periodontitis and appropriate for use in clinical trials are periodontal attachment level and alveolar bone status. Improved methods for measurement of both with excellent accuracy and reproducibility are now becoming available. Studies performed on untreated patients over the past decade demonstrate clearly that disease-active and disease-inactive pockets exist, at any given point in time most are inactive, disease progression is episodic and in most patients infrequent, and a rather small portion of the population--possibly around 5%--are unusually susceptible to rapid disease progression. These observations need to be taken into account in enrolling subjects into periodontitis clinical trials. Conducting a prestudy to identify actively diseased sites and susceptible subjects, or screening to enrich the proportion of active sites, is recommended. Determination of study duration is a very complex issue. It is related to the length of time required for maximal change and stabilization to occur in the biological events to be observed, the outcome variable(s) used to detect change, and the nature of the therapeutic interventions to be studied. No single duration is applicable to all periodontitis clinical trials. Large gaps in our knowledge about the design of periodontitis trials still exist, and additional research is needed.

Microbiological testing in the diagnosis of periodontal disease

The oral microbiota plays a primary role in the initiation and progression of the most common forms of periodontal disease. Because of the multiplicity of factors that control the establishment and long-term evolution of the oral microbiota, a great deal of heterogeneity exists in the composition of the periodontal microbiota among individual subjects. Despite these individual differences and the complex interactions between bacteria and the host and among bacteria, an association has been demonstrated between certain species and various forms of periodontal disease. However, the predictive value of either positive or negative tests for selected bacterial species has not proved to be high enough for routine use in clinical practice. Nevertheless, bacteriological tests have been of value in the management of patients with juvenile periodontitis and refractory forms of periodontal disease. The increasing availability of diagnostic laboratory services and diagnostic kits for office use will make it easier for the practitioner to select appropriate antimicrobial treatments and monitor patients undergoing antimicrobial therapy.

A sensitive enzymatic method (SK-013) for detection and quantification of specific periodontopathogens

Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola have been found to predominate in periodontal pockets of patients with adult periodontitis. These microorganisms hydrolyze the synthetic peptide N-benzoyl-DL-arginine-2-naphthylamide (BANA). In this study, we developed an enzymatic method, designated SK-013, to detect the existence of these microorganisms in subgingival plaque bacteria. This enzymatic method was based on the observation of the hydrolysis of N-carbobenzoxy-glycyl-glycyl-arginyl-3,5-dibromo-4-hydroxyaniline (N-CBz-Gly-Gly-Arg-DBHA) and made more sensitive by adding an enhancing system. The SK-013 was specifically positive for P. gingivalis, B. forsythus, T. denticola, and some strains of Capnocytophaga species, but was not specific for any of the other bacterial strains tested. This SK-013 system may be valuable for detection and quantification of periodontal disease-associated bacteria in subgingival plaque and thus for diagnosis of periodontal infections.

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

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.

Metronidazole in periodontitis: reduced need for surgery

A considerable amount of circumstantial evidence indicates that most forms of periodontitis are due to the presence or dominance of a finite number of bacterial species in the subgingival plaque. Almost all of the putative pathogens are anaerobic species, indicating that most forms of periodontitis could be diagnosed as anaerobic infections. In this double-blind investigation, patients with elevated proportions or levels of spirochetes in 2 or more plaque samples, i.e., 60% spirochetes, were randomly assigned to receive either metronidazole, 250 mg 3 x a day for 1 week, or placebo (positive-control) after the completion of all debridement procedures. When the patients were re-examined 4 to 6 weeks later, the patients in the metronidazole group (n = 15) exhibited a highly significant (p less than 0.01) reduction in probing depth and apparent gain in attachment levels relative to the patients (n = 18) in the positive-control group about those teeth that initially had probing depths of 4 to 6 mm. This pattern was also observed about teeth that initially had probing depths greater than or equal to 7 mm. This reduction in probing depths and apparent gain in attachment was associated with a significant reduction in the need for periodontal surgery in the metronidazole-treated patients (difference 8.4 teeth per patient) compared to the positive-control patients (2.6 teeth per patient). These clinical improvements in the metronidazole group were associated with significantly lower proportions of spirochetes, selenomonads, motile rods, and P. intermedius, and a significantly higher proportion of cocci in the plaques. These findings indicate that systemic metronidazole, when given after all the root surface debridement is completed, leads to additional treatment benefits, including a reduced need for surgery, beyond that which can be achieved by debridement alone.

The use of genomic DNA fingerprinting in studies of the epidemiology of bacteria in periodontitis

Recent studies of microbial epidemiology emphasizing the genetic organization and distribution of organisms associated with orofacial infections have led to new insights into the possible origins of pathogenicity. Studies into genetic heterogeneity, acquisition and transmission of these organisms have been markedly advanced by the utilization of the powerful technique of genomic DNA fingerprinting. Characteristic fingerprints for each bacterial isolate can be produced by cleavage of high molecular weight genomic DNA by restriction endonucleases. It is assumed that each DNA fingerprint represents a clonal type. In this report, we review and analyze studies of the epidemiology of bacteria associated with orofacial infections with an emphasis on periodontal disease. Studies of nontypable (NT) Haemophilus influenzae associated with recurrent otitis media illustrate the utility of this technique. DNA fingerprinting clearly demonstrates genetic heterogeneity of NT H. influenzae isolates, and clonality of infection of any individual. Furthermore, DNA fingerprinting has shown that the same clonal type is seen in siblings concurrently suffering from otitis media, suggesting horizontal transmission within the family. Studies of mutans Streptococci also show extensive genetic heterogeneity and show vertical transmission of a predominant clonal type only from mother to infant, but not from father to infant. Studies of Actinobacillus actinomycetemcomitans show considerable genetic heterogeneity among monkey isolates. Thus far, three clonal types have been reported with DNA fingerprinting among isolates from periodontal patients, but additional genetic heterogeneity can be found using specific DNA fragments as probes in hybridization experiments. Intrafamilial transmission of A. actinomycetemcomitans has been demonstrated. Porphyromonas (Bacteroides) gingivalis shows extensive genetic heterogeneity and case reports suggest clonal infection of any one individual. In contrast, results with DNA fingerprinting of Eikenella corrodens, Fusobacterium nucleatum, and Bacteroides intermedius show that individuals may be infected with 2 or more clonal types. These studies point to the great potential of DNA fingerprinting for investigating the epidemiology of putative orofacial pathogens. Such studies with periodontal microorganisms will likely reveal steps in the acquisition, intraoral and person-to-person transmission, which then could possibly be inhibited or interfered with to prevent periodontal disease or its recurrence.

Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

Subjects of the past decade in the dental literature are reflected in this year's Committee report. We note the decrease in the prevalence of caries, the influence of dental implants, the advancements in dental materials, and the continued efforts to control adhesive events in the oral cavity. This year we included comments from and about many significant review articles published this past year. The Committee continues to be concerned about the quality of some of the work reported and the quality of the reporting. We have attempted to select the distinguished work, that which provides new information to our profession. The subjects covered include pulp biology, caries prevention, periodontics, implants, craniomandibular function and dysfunction, occlusion, and dental materials.

Detection of two anaerobic periodontopathogens in children by means of the BANA and ELISA assays

The mouths of young children become colonized by a variety of bacteria, but there have been only a few studies that have sought the presence of periodontopathic species in this population. Almost all of these studies used culturing techniques rather than the newer detection methodologies for various periodontopathogens. Studies in adults have shown that Treponema denticola and Porphyromonas (Bacteroides) gingivalis can be detected in dental plaque by use of the BANA and ELISA diagnostic tests. In the present study, plaque samples from four subgingival sites in each of 157 children (aged from two to 18 years) were tested for BANA hydrolysis with a BANA reagent card, and for T. denticola and P. gingivalis with an ELISA assay. Anaerobic periodontopathogens hydrolyzing the BANA substrate were found to be present in at least one of four plaque samples in 88 children (56%). T. denticola and/or P. gingivalis were detected by ELISA in at least one plaque sample in each of 135 children (86%). This study shows that children are widely colonized by these micro-organisms. A higher proportion of Black children than Caucasian children was colonized by these BANA-positive organisms. Also, children having a parent with a documented history of periodontal disease were more likely to be BANA-positive than were children of parents with unknown periodontal status.

Periodontal diagnosis in the 1990s

Clinicians are usually inclined to reduce data obtained from diagnosis to a simpler form such as "yes or no" answers in order to obtain useful parameters for daily practice. It should be realized, however, that the diagnostic process very rarely exhibits "black and white" situations. Rather the evaluation of numerous "grey levels" is imperative. The diagnostic process, therefore, remains always incomplete and inaccurate, and it represents an evaluation of probabilities rather than certainties. For this reason, the diagnostician should realize and understand the mathematical relations between the information provided by diagnostic tests and the clinical situation actually present at the time of the test. This will allow one to convert diagnostic results into therapeutic procedures with a high degree of confidence. Since results from diagnostic tests are quite often used to decide on treatment, complex data are reduced to simple dichotomy, such as presence or absence of disease, normal or abnormal conditions, etc. In order to react to diagnostic tests in an ordinal, dichotomous manner, the clinician has to choose a particular level of a test at which he initiates treatment without having the assurance that this level represents the one and only standard at which treatment has to be initiated.

The utility of the BANA test for monitoring anaerobic infections due to spirochetes (Treponema denticola) in periodontal disease

Treponema denticola, Porphyromonas gingivalis, and Bacteroides forsythus each possesses an enzyme(s) that hydrolyzes the synthetic substrate benzoyl-DL-arginine-naphthylamide (BANA). The presence of these organisms in a subgingival plaque sample can be determined by the ability of the plaque to hydrolyze BANA. In the present study, we describe the usefulness of the BANA test at various stages of a clinical trial of the efficacy of metronidazole in the treatment of periodontal disease. A BANA-positive test was significantly associated with high levels and proportions of spirochetes in the plaque, so that it provided information comparable with that which could be obtained by a microscopic examination of the plaque. Patients with such anaerobic spirochetal infections were randomly assigned to a group receiving either metronidazole or placebo (250 mg, three times a day) for one week and whose teeth were scaled and root-planed. The advantages of the decision that metronidazole be used were apparent from the comparison with the results obtained in the patients who received only the scaling and root planing. The initially BANA-positive teeth in the patients treated with metronidazole, scaling, and root planing gained attachment and exhibited a significant reduction in the need for periodontal surgery, when compared with the BANA-positive teeth in the patients who received only placebo, scaling, and root planing. After the conclusion of this therapy, those teeth with persistent BANA-positive plaques had significantly higher proportions and levels of spirochetes than did the teeth with BANA-negative plaques.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzoyl-arginine naphthylamide (BANA) hydrolysis by Treponema denticola and/or Bacteroides gingivalis in periodontal plaques

Treponema denticola and Bacteroides gingivalis are among the few recognized species found in periodontal pockets that can hydrolyze the synthetic peptide N-benzoyl-DL-arginine-2-naphthylamide (BANA). We determined the presence of these periodontal pathogens in BANA-positive and -negative plaque samples through the use of indirect immunofluorescent antibody techniques. Eighteen of 27 diseased sites gave BANA-positive reactions, and 9 gave BANA-negative reactions. T. denticola was present in 16 of 18 BANA-positive reactions, whereas B. gingivalis was detected in 9 of the 18 BANA-positive reactions. T. denticola was present in 1 and B. gingivalis in 2 of the 9 BANA-negative reactions. Neither organism was detected in the 19 healthy sites that were negative for BANA. All measured differences between BANA-positive and BANA-negative plaques obtained in the same individuals were statistically significant. The accuracy of the BANA test, compared with clinical parameters such as bleeding upon probing and increased probing depth, was about 80%. The accuracy of the test in detecting the presence of T. denticola was 93%, for B. gingivalis, 76% and for T. denticola and/or B. gingivalis, 96%. This study indicated that BANA-positive plaques were associated with the presence of T. denticola and/or B. gingivalis, that T. denticola was found at a greater frequency and levels in BANA-positive plaques than B. gingivalis, and that the presence of these organisms was associated with clinical disease.