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Biomedical subjects

M A Listgarten

Publications and source records attributed to M A Listgarten.

At least 19 recordsLinked to original sources
PubMed1992

Peptostreptococcus micros in human periodontitis.

Peptostreptococcus micros is a recognized pathogen in medical infections, and its association with progressive periodontitis was examined in this study. P. micros was isolated from paper-point subgingival samples on anaerobic enriched blood agar plates and identified on the basis of cellular and colonial morphology and selected biochemical tests. In a cross-sectional study involving 907 people with advanced adult periodontitis, 127 with early-onset periodontitis, and 12 with localized juvenile periodontitis, P. micros in these patient groups occurred with a prevalence of 58-63%. In culture-positive patients, P. micros averaged 12-15% of total viable counts. P. micros demonstrated similar occurrence and proportional recovery in all age groups. In a longitudinal study of 91 adult periodontitis patients on maintenance therapy, P. micros demonstrated a significantly higher prevalence in disease-active than in disease-inactive patients (47% vs 14%). Mechanical subgingival debridement and 0.12% chlorhexidine pocket irrigation was unable to eradicate subgingival P. micros from 18 of 22 adult periodontitis patients. In vitro antimicrobial susceptibility testing showed P. micros to be sensitive to therapeutic levels of penicillin, clindamycin and metronidazole. Our findings indicate that P. micros is a potential pathogen in adult periodontitis. The methods for its eradication from subgingival sites remain to be determined.

Adult↗
PubMed1992

General issues in efficacy, equivalency, and superiority trials: clinical considerations.

The design of clinical trials aimed at treating different types of periodontal diseases must take into account the prevalence of the disease in the population and the relationship of various descriptors, which may vary from disease to disease. For screening purposes, patients should be selected with disease in the high-severity range, in order to maximize the likelihood of detecting a therapeutic effect. Subsequent trials may be designed around a more representative group of subjects. Therapies must be evaluated on the basis of actual clinical changes, rather than their effect on presumed etiologic factors. The observed changes must be of clinical as well as statistical significance. The distribution of periodontal diseases within a dentition may affect as few as one or as many as over one hundred sites. Strategies are needed to correlate events observed at sites within the dentition, i.e. tooth surface-based measurements or scores, with events that are subject-based, e.g. concentration of blood or salivary components.

Dental Plaque↗
PubMed1992

Wolinella recta in adult gingivitis and periodontitis.

Wolinella recta has been associated with adult periodontitis, but its role in the disease remains uncertain. This report clarifies the distribution of W. recta in periodontally healthy and diseased subjects, and treated patients with recurrent disease. A specific polyclonal rabbit antiserum against W. recta strain 372 was used for indirect immunofluorescence localization of W. recta in dental plaque from untreated and treated patients. Supragingival plaque was collected from 15 periodontally healthy individuals (H), 10 adults with mild gingivitis (G1), 8 with severe gingivitis (G2) and 15 with periodontitis (AP). Subgingival samples from 23 diseased sites (G2 and AP) were examined as well. There was a significant difference (p = 0.000) between the proportions of W. recta in subgingival (4.4%) vs. supragingival (0.3%) plaque samples from AP. A significant difference (p = 0.000) in W. recta proportions was also detected between subgingival plaque samples of AP (4.4%) vs. G2 (1.2%). No significant difference in the mean % of W. recta was found between supragingival plaque of AP (0.3%) and G2 (0%), and samples of G1 (0.01%) and H (0.1%). In a separate study, 85 adults previously treated for moderate to severe adult periodontitis were monitored over a 12-month period for evidence of disease recurrence. Recurrent disease was detected at 32 sites in 18 subjects. Of these, 20 sites in 13 subjects were positive for W. recta. With subjects as the experimental unit, a significant increase in the proportions of W. recta was found at sites with recurrent disease (3.12%) as compared to stable, paired control sites (0.24%), but only when sites with breakdown and positive for W. recta were compared with their controls. These results indicate that W. recta is associated with some, but not all sites with advanced adult periodontitis. The association of W. recta with gingivitis was not statistically significant.

Adult↗
PubMed1992

Light and transmission electron microscopy of the intact interfaces between non-submerged titanium-coated epoxy resin implants and bone or gingiva.

This experiment was aimed at studying the intact tissue/implant interface of non-submerged dental implants with a titanium surface. Epoxy-resin replicas were fabricated from 3.05 x 8 mm cylindrical titanium implants with a plasma-sprayed apical portion and a smooth coronal collar. The replicas were coated with a 90-120-nm-thick layer of pure titanium and autoclaved. The coated replicas were inserted as non-submerged endosseous implants in the edentulous premolar region of dog mandibles and allowed to heal for three months. Jaw sections containing the implants were processed for light and electron microscopic study of the intact tissue/implant interface with and without prior demineralization. Gingival connective tissue fibers were closely adapted to the titanium layer, in an orientation more or less parallel to the implant surface. There was no evidence of any fiber insertions into the surface irregularities of the smooth or rough titanium surface. Undemineralized bone was intimately adapted to the titanium surface without any intervening space. In demineralized sections, the collagen fibers of the bone matrix tended to be somewhat thinner and occasionally less densely packed in the vicinity of the implant surface. However, they extended all the way to the titanium surface, without any intervening fibril-free layer.

Alveolar Process↗
PubMed1992

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.

Bacteria↗
PubMed1992

Monitoring the periodontal microbiota as an adjunct to periodontal therapy: rationale, interpretation of test results and application to patient management.

Recent developments in our understanding of the relationship of the oral microbiota to periodontal diseases have led to improved approaches to controlling the pathogenic influence of certain bacterial species. In addition to non-specific control of bacterial accumulations in the sulcus region, antibiotics may be useful in suppressing persistent species with pathogenic potential. This approach is indicated in cases that do not respond adequately to mechanical plaque control measures or certain categories of periodontal diseases likely to be caused by a specific infection. Monitoring the composition of the microbiota before, during and after antimicrobial therapy is helpful in the selection of appropriate antimicrobial agents, monitoring the effectiveness of the therapy and detecting the return of undesirable microorganisms.

Bacteria↗
PubMed1991

Incidence of periodontitis recurrence in treated patients with and without cultivable Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Porphyromonas gingivalis: a prospective study.

A total of 98 adults previously treated for moderate to advanced periodontitis and on a trimonthly recall schedule were screened for the presence of critical levels of Actinobacillus actinomycetemcomitans, Prevotella (Bacteroides) intermedia, and Porphyromonas (Bacteroides) gingivalis. Patients with at least 2 positive sites were placed in a positive group and patients without or with low levels of these bacteria in a negative group. During the 30-month study the incidence of disease recurrence was greater in the positive group, but did not reach statistical significance. Positive patients with deeper pockets tended to be at greater risk of developing recurrent disease than those with shallower pockets. In the positive group only, both A. actinomycetemcomitans recovery and antibody levels to A. actinomycetemcomitans strain NCTC 9710 (serotype c) were inversely correlated with disease recurrence. The presence of A. actinomycetemcomitans and P. intermedia above critical levels did not reliably predict future episodes of disease recurrence in this population. The sparse recovery of P. gingivalis did not permit us to assess its diagnostic value. With the exception of P. gingivalis, for which insufficient data were available, the results indicate that the presence or absence of the above bacterial species cannot of itself serve as a reliable predictor of future episodes of recurrent disease in a population of treated patients on a regular trimonthly recall schedule.

Actinobacillus↗
PubMed1990

Distribution of bacterial morphotypes around natural teeth and titanium implants ad modum Brånemark.

The subgingival plaque around both teeth and implants was analysed by means of differential phase-contrast microscopy. It was noted that, in comparison to natural teeth, the subgingival samples from implants were more frequently too small to provide adequate bacterial counts. In 24 partially edentulous patients (with implants and teeth in the same jaw), no significant differences in the distribution of bacterial morphotypes could be found between implants and natural teeth. The %s of coccoid cells, motile rods, spirochetes and other bacteria were 65.8, 2.3, 2.1, and 29.8 for implants and 55.6, 4.9, 3.6, and 34.9 for teeth, respectively. However, when the plaque composition on the implants of fully edentulous patients was compared with those of teeth or implants of partially edentulous patients (with teeth and implants in the same and/or opposite jaw), significant differences appeared. In fully edentulous patients, more coccoid cells (71.3%) and significant fewer motile rods (0.4%) and spirochetes (0.0) were found around the implants. The results suggest that teeth may serve as a reservoir for the bacterial colonisation of titanium implants in the same mouth.

Dental Implants↗
PubMed1990

Statistical properties of some clinical measures of gingivitis and periodontitis.

Various statistical properties of the plaque index, the gingival index, and the whole-mouth averages of pocket depth and attachment level measurements were examined using data from a 4-year randomized trial of 80 patients with a history of treated periodontal disease. Departures from normality were assessed by the median of the standardized distribution, by the coefficients of skewness and kurtosis, and by the Kolmogorov goodness-of-fit test. The relative precisions of probing pocket depth and of attachment level were measured, as were correlations between repeated measurements over time for the four clinical measures. The distribution of the plaque index was far from normal, but the distribution of its logarithm was more nearly normal. The distributions of the other clinical measures were effectively normal to varying degrees of approximation. With only rare exceptions, correlations between repeated measurements on the same clinical variable remained relatively constant no matter how far apart in time the measurements were made, at least up to 4 years. The whole-mouth mean of the attachment level measurements seemed to be relatively more precise than the whole-mouth mean of the pocket depth measurements.

Analysis of Variance↗
PubMed1989

Comparative longitudinal study of 2 methods of scheduling maintenance visits: 4-year data.

116 subjects were recruited from a population of patients previously treated for adult periodontitis and maintained in periodontal health by means of periodic prophylaxes every 3-6 months. The subjects were divided into a control (C) and a test (T) group. A total of 33 patients in the T group and 47 in the C group completed the 4-year study. The C subjects were examined every 6 months and given a prophylaxis every 3 months. The patients in the T group were examined at similar intervals, but prophylaxes were administered according to the individualized scheme of Listgarten and Shiffter, on the basis of a differential microscopic count of subgingival bacterial morphotypes. Recurrent periodontitis was defined as an increase in probing depth of 3 mm or more from baseline measurements. Teeth so affected were sampled microbiologically when the diagnosis of recurrent disease was made and "exited" from the study for treatment. A control microbial sample was taken at the same time from a previously-defined pooled sample of non-affected surfaces with comparatively high, but stable probing depths. During a 4-year period, more than half of the subjects developed at least one recurrence of disease, and one-third of the subjects had 2 or more recurrences of periodontitis. Disease recurred on approximal surfaces 81% and on orovestibular surfaces 19% of the time. There were no significant differences in the rate of disease recurrence between the C and the T group, even though recall intervals in the T group at the 4-year examination averaged 19.4 months and an average of 30.6 months had elapsed since the previous prophylaxis. Both groups exhibited similar plaque index and gingival index scores, similar probing depth and attachment level measurements, and similar proportions of different bacterial morphotypes during the 4-year study. However, differences were noted between examinations for both groups with respect to most of these criteria. This study provides 4-year longitudinal data on the clinical and certain microbiological characteristics of a population of adult patients previously treated for moderate to advanced periodontitis, and subsequently placed on periodontal maintenance. The results indicate that some of these patients may remain in good periodontal health despite the lack of regular tri-monthly recall visits, and that microscopic monitoring of the subgingival microbiota may be of value in identifying these individuals.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

Effect of subgingival irrigation with tetrapotassium peroxydiphosphate on scaled and untreated periodontal pockets.

A total of 20 test and 20 control subjects completed an 8-week double blind clinical trial aimed at testing the therapeutic efficacy of a 7% tetrapotassium peroxydiphosphate (PDP) solution administered as a subgingival irrigant to scaled and untreated periodontal pockets. Each patient provided similar contralateral pockets with probing depths at base line of 5 mm or more (mean 6.25 mm). One pocket was selected at random for a thorough scaling, immediately following the base line examination (examination 1). The examination of each experimental site consisted of Plaque Index (P1I) and Gingival Index (GI) scores, probing depth (PD) and attachment level (AL) measurements (in mm), and a differential microscopic proportional count of certain subgingival bacterial morphotypes, namely coccoid cells, motile bacteria (not including spirochetes), spirochetes and all residual bacterial morphotypes. Test patients received coded irrigators containing the active ingredient PDP, while control patients received irrigators containing a placebo rinse similar to the test solution, but without PDP. The participants were instructed to irrigate the test sites twice a day. They were re-examined after four weeks (examination 2) and eight weeks (examination 3) from the base line examination. The results indicated that scaling and irrigation produced a significant decrease from the initial P1I and GI scores, and the PD and AL measurements. The proportions of coccoid cells were significantly increased, while the proportions of motile bacteria and spirochetes were significantly decreased. Irrigation of unscaled pockets resulted in a modest, but significant decrease in the P1I and GI scores.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
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↗