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Biomedical subjects

M A Listgarten

Publications and source records attributed to M A Listgarten.

At least 55 records · Page 3Linked to original sources
PubMed1989

Clinical and microbiological characteristics of treated periodontitis patients on maintenance care.

A population of 98 adults previously treated for moderate to advanced adult periodontitis and currently maintained in a recall program for at least one year were recruited for this study. The ultimate purpose of the study is to determine whether the presence of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Bacteroides intermedius in selected periodontal sites can predict the future clinical course of these patients, particularly with respect to disease recurrence. This report presents the clinical design of the study which allows comparisons between sites positive and negative for these species in infected patients, and between sites in infected patients and comparable sites in non-infected patients. In addition, some base line clinical and microbiological data for these patients are presented. The distribution of PII and GI scores tended to be highest for molars, with the remaining teeth having similar scores. Probing depth measurements were greater for mesio-distal than oro-vestibular recordings. A bilaterally symmetrical pattern of increasing probing depth was noted from the midline distally on mesio-distal as well as oro-vestibular surfaces. Sites positive for the target organisms listed above tended to have greater probing depths (mean: 4.14 +/- 0.1 mm) than non-infected sites in the same patients (mean: 3.76 +/- 0.1 mm) or comparable sites in non-infected patients (mean: 3.54 +/- 0.1 mm).

Actinobacillus↗
PubMed1989

Human junctional epithelium as a pathway for inflammatory exudation.

Photographic montages of transmission electron micrographs of the dentogingival region have made it possible to assess the morphologic alterations that occur in the junctional and the oral sulcular epithelium as a result of mild gingival inflammation. Enlargements of the intracellular spaces in the junctional epithelium varied in size and shape from isolated alveolate enlargements, often containing isolated granulocytes, to channel-like pathways oriented in an apico-coronal direction and frequently filled with rows of granulocytes. In contrast to artifactitious spaces, these enlarged intercellular spaces failed to reveal the presence of ruptured intercellular bridges and contained well preserved undistorted granulocytes with round profiles. Moderately electron dense material within the enlarged intercellular spaces probably represented proteins from the fluid exudate, precipitated by the fixation process. The rate of normal junctional epithelial turnover appeared to be insufficient to compensate for the above morphological alterations brought about by the inflammatory process. Mononuclear cells, mostly lymphocytes, were preferentially located in the connective tissue side of the junctional epithelium. Their low numbers in the gingival sulcus suggest that they are passively carried into the sulcus as a result of normal turnover of the junctional epithelium, whereas granulocytes, which account for the majority of leucocytes in the sulcus, actively migrate through the junctional epithelium.

Bicuspid↗
PubMed1989

[Sulcus and coronal junctional epithelium in mild gingivitis. A retrospective study].

Is the presence of mild gingivitis in humans synonymous with early pocket formation? In order to answer this question, buccal gingival biopsies from 5 children, 9 to 12 years of age, were studied by light and electron microscopy. These biopsies included the entire topographically intact gingival sulcus and coronal junctional epithelium. The results indicated that in the presence of supragingival plaque and mild gingival inflammation, the coronal junctional epithelium acquired a loose structure. However, this structural change did not affect the ability of the junctional epithelium to maintain its attachment to the tooth. The loose epithelial structure results in part from the apico-coronal migration of neutrophilic granulocytes through the junctional epithelium and the appearance throughout the junctional epithelium of irregular, cavernous enlargements of the intercellular spaces that are filled with tissue fluid. The degree to which the epithelial structure is altered varies over short stretches of the dentogingival junction. The findings are interpreted in the light of current knowledge in pathophysiology. The above question appears to have a negative answer.

Child↗
PubMed1988

Ultrastructure of the flagellar basal body complex of Centipeda periodontii.

The morphology and insertion of the flagellar basal body complex into the cell wall of Centipeda periodontii was studied by electron microscopy of both negatively and positively stained specimens. Freshly harvested cells were examined either after treatment with 0.2% sodium dodecyl sulfate (SDS) for 2 min and negatively stained with phosphotungstic acid, or after treatment according to standard electron microscopy procedures that included positive staining. Small numbers of flagella were dislocated from the cell body after treatment with SDS. The flagella demonstrated an unusual basal body structure: five rings were attached to a rod in a three-ringed (distal) and two-ringed (proximal) patterns; ring diameters produced a distinctive hourglass shape. The cell envelope was typical for gram-negative bacteria with a cytoplasmic membrane and an outer membrane separated by a peptidoglycan layer. Basal body length and cell wall width were in general agreement, approximately 29 nm. Cell wall width exceeded dimensions previously reported for Escherichia coli; this was attributed to an unusually thick peptidoglycan layer.

Flagella↗
PubMed1988

Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans in human periodontal diseases.

Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans seem to be major pathogens in advancing periodontitis in man. First, these organisms are recovered in higher prevalence and proportions from progressive periodontitis lesions than from quiescent periodontal sites. Second, antibody levels against B. gingivalis and A. actinomycetemcomitans are markedly elevated in serum and gingival crevice fluid of periodontitis patients compared to normal controls. Third, B. gingivalis and B. intermedius elaborate potent proteases and A. actinomycetemcomitans various noxious substances which have the potential to perturb important host defenses and to disintegrate key constituents of the periodontal tissues. Monitoring these bacteria in advanced periodontal lesions may greatly assist the assessment of treatment efficacy and risk of further periodontal breakdown.

Actinobacillus↗
PubMed1988

The role of dental plaque in gingivitis and periodontitis.

A dynamic equilibrium between the periodontal microbiota and the host generally results in a clinical state of periodontal health, characterized by minimal inflammatory changes in the marginal gingival tissues. Maintenance of health is most easily achieved by controlling the resident mass of bacteria. In rare instances, control of specific microorganisms may be indicated. Lack of microbial control may lead to an imbalance between the microbiota and the host due to a markedly increased microbial mass and/or increased virulence of the micro-organisms present. Such alterations in the host-parasite equilibrium may result in transient episodes of tissue destruction and, in the long term, to cumulative damage to the periodontal tissues.

Bacterial Physiological Phenomena↗
PubMed1988

A rationale for monitoring the periodontal microbiota after periodontal treatment.

Strict control of dental plaque accumulation remains the cornerstone of successful maintenance of the treated patient. However, some recurrences of periodontitis appear to take place despite good oral hygiene habits. A proportion of these are likely due to qualitative features of the periodontal microbiota rather than merely increased mass. Microscopic as well as cultural monitoring of qualitative features of the periodontal microbiota may be helpful in detecting critical changes. This review presents some of the research findings that provide a rationale for microbiological monitoring. Some of the advantages as well as difficulties encountered with these procedures are discussed.

Bacteria↗
PubMed1986

Comparative longitudinal study of 2 methods of scheduling maintenance visits; 2-year data.

This report compares the clinical and microbiological status of 2 groups of subjects with treated periodontis on different maintenance schedules. 43 control (C) subjects were given prophylaxes every 3 months. 40 test (T) subjects were given this service on a flexible schedule according to the proportions of spirochetes and/or motile rods in fresh smears of subgingival scrapings. Both groups were examined every 6 months clinically and microbiologically. This report presents base line, 1- and 2-year data. Generally, mean values for both groups did not differ significantly from one another. Both groups exhibited comparable increases in GI and PLI scores during the first 2 years of this study. No change in probing depth was noted between base line and the 2-year examination. However, a slight increase in attachment level, as determined by probing, was noted in both groups. Both groups also exhibited similar proportions of bacterial morphotypes at base line and subsequent examinations. Disease recurrence, defined as an increase in probing depth of 3 mm or more from base line on any tooth surface during the 2-year period, tended to be more prevalent in the C than in the T group (15/43 C and 9/40 T subjects). However, the proportional difference between the groups was not statistically significant. Subjects with disease recurrence in the T group had greater proportions of spirochetes at base line than subjects in the same group without disease recurrence (20.2% versus 9.8%, p less than 0.01). This difference in proportions persisted if both groups were examined jointly, but was only of borderline significance (16.0% versus 10.5%, p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Serum IgA and IgG antibodies to Treponema vincentii and Treponema denticola in adult periodontitis, juvenile periodontitis and periodontally healthy subjects.

13 patients with untreated adult periodontitis (AP) were compared to 8 subjects free of periodontal disease (H) with respect to plaque index (PlI), gingival index (GI), probing depth (PD) and differential counts of subgingival bacterial morphotypes from a pooled sample of 6 surfaces with the greatest probing depth. Serum antibody levels to T. vincentii and T. denticola strains were also determined in these subjects as well as in the sera from 5 subjects with localized juvenile periodontitis (LJP). Subjects with AP had significantly elevated proportions of spirochetes and motile rods and lower proportions of coccoid cells than H subjects. They also exhibited significantly higher PlI and GI scores and greater probing depths. Antibody levels were normalized against a standard serum and expressed as ELISA units (EU). IgA and IgG antibody levels to all tested spirochete strains were significantly elevated in AP subjects as compared to subjects in group H or subjects with LJP. No significant differences in antibody titers were detectable between the H and LJP groups with respect to any of the tested strains. No significant correlation could be demonstrated between serum antibody titers to any of the oral spirochete strains tested and the proportions of oral spirochetes determined microscopically.

Adult↗
PubMed1986

Failure of a microbial assay to reliably predict disease recurrence in a treated periodontitis population receiving regularly scheduled prophylaxes.

The purpose of this study was to evaluate the reliability of differential dark-field microscopy (DDFM) of subgingival bacteria to correctly predict the recurrence of periodontitis in treated patients on 2 different recall schemes. The results are based on data from 51 patients on 3-month recalls (C group) and 39 patients (T group) who received periodontal prophylaxes according to a customized regimen based on DDFM of subgingival bacterial morphotypes. No significant differences were detected in the rate of recurrence of periodontitis between the 2 groups, although the incidence of disease recurrence tended to be greater in the C group. The proportions of spirochetes and motile rods observed at base line, or the average of the values observed at base line, 3 months and 6 months, were compared between subjects with and without disease recurrences. Significantly elevated proportions of these bacterial morphotypes were observed in patients of the T group who demonstrated evidence of disease recurrence during the first year as compared to subjects without disease recurrence. No significant differences could be detected in bacterial morphotypes between patients resistant to disease recurrence and those who developed recurrences at some time during the 3-year period covered by this report. The ability of DDFM of subgingival bacterial morphotypes to predict future disease occurrence was tested for 1- and 3-year periods, in both the C and T groups. The test appears to be reliable only for subjects on the experimental maintenance regimen (group T) and for prediction of disease recurrence for the initial 1-year period.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria↗