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Thomas E. Rams

Bio: Thomas E. Rams is an academic researcher from Temple University. The author has contributed to research in topics: Periodontitis & Chronic periodontitis. The author has an hindex of 37, co-authored 72 publications receiving 4854 citations. Previous affiliations of Thomas E. Rams include National Institutes of Health & University of Southern California.


Papers
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Journal ArticleDOI
TL;DR: This volume aims to provide a comprehensive evaluation of the distribution of various types of periodontal diseases from each of the world’s five major geographic regions.
Abstract: This volume aims to provide a comprehensive evaluation of the distribution of various types of periodontal diseases from each of the world’s five major geographic regions. Epidemiology is the study of the health and disease in populations, as compared to individuals (20). Study of the distribution of human periodontal diseases and their risk factors on a global scale offers a unique investigational model that can provide power and generalization to observations on the periodontium made initially among more limited populations. In assessing causation between periodontal diseases and their suspected etiologic risk factors, it is useful to demonstrate consistency of the relationships in multiple, representative population samples. When diverse study approaches in various populations by different investigators produce similar conclusions on the distribution of periodontal diseases and/or their associations with putative risk factors, then one can be more confident that real phenomenon and/or causal relationships exist (29). Indeed, population-based studies provide external validity to observations obtained from more discrete subject groups, and enable generalization of the conclusions (14). Alternatively, differences in periodontal disease patterns among various population groups can be exploited to uncover previously unidentified risk factors that may not be expressed in all populations. Available population-based periodontal disease data originate from studies encompassing a wide range of objectives, designs and measurement criteria (18). The lack of standardized study design, definition of periodontal disease status, methods for disease detection and measurement, and criteria for subject selection markedly limit interpretation and

490 citations

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TL;DR: A review of published papers reveals that appropriate systemic antibiotic therapy may enhance healing in patients with recent or high risk of periodontal breakdown and several promising antimicrobial agents for periodontitis treatment need testing in placebo-controlled, double-blind, randomized clinical trials.
Abstract: Antibiotic treatment of periodontitis aims at eradicating or controlling specific pathogens. Prime candidates for antibiotic therapy are patients with recently diagnosed active periodontitis or a history of recurrent disease who fail to stabilize following mechanical/surgical therapy. Since a variety of microbes with differing antimicrobial susceptibility profiles may cause periodontitis, selection of antimicrobial agents should be based on proper microbial diagnosis and sensitivity testing, as well as consideration of the patient's medical status. The risk of treating chemotherapeutically solely on the basis of clinical features, radiographic findings or a limited microbiological analysis, is failure to control the pathogens or overgrowth of new pathogens. A review of published papers reveals that appropriate systemic antibiotic therapy may enhance healing in patients with recent or high risk of periodontal breakdown. Systemic antibiotic therapy seems more predictable than topical administration in eradicating periodontal pathogens from deep periodontal pockets. Several promising antimicrobial agents for periodontitis treatment need testing in placebo-controlled, double-blind, randomized clinical trials.

334 citations

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TL;DR: It is suggested that yeasts or enteric rods or pseudomonads occur in the subgingival flora of about one-third of “refractory” adult periodontitis patients, and is cautioned against using antibiotics without prior microbiological screening in treating this patient group.
Abstract: The subgingival occurrence of yeasts and species of Enterobacteriacae and Pseudomonas was studied in 500 adults with severe periodontitis All subjects had sites non-responding or “refractory” to conventional periodontal therapy Most subjects had received one or more courses of broad-spectrum systemic antibiotics Subgingival microbial samples were collected with paper points and transported in VMGA III The bacterial samples were plated on enriched brucella blood agar and incubated anaerobically, and on TSBV, TBC, and Sabouraud agar, which were incubated in 10% CO2 Yeasts were speciated using the API 20C micro-method system and the germ tube test (for Candida albicans) Enteric organism's and pseudomonads were speciated with the API 20E kit system Yeasts, enteric rods and pseudomonads were subjected to antibiotic susceptibility testing The occurrence of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Bacteroides intermedium was also determined in the patients studied In the 500 periodontitis patients, yeasts were detected in 84 (168%), enteric rods or pseudo-monads in 51 (102%), and both yeasts and enterics or pseudomonads in 6 (12%) Candida albicans comprised 833% of the isolated yeasts Enterobacteriaceae averaged 21–39% of the cultivable flora in culture-positive cases, with Enterobacter cloacae, Enterobacter agglomerans, Proteus mirabilis, Klebsietta pneumonias, and Klebsiella oxytoca being the most frequent species Pseudomonas aeruginosa was isolated from 10 patients, averaging 234% of the cultivable subgingival flora All Candida isolates, and 86–95% of the enteric rods and pseudomonads, were resistant to 1 μg/ml of tetracycline, penicillin G, and erythromycin In patients positive for yeasts, enteric rods or pseudomonads, A actinomycetemcomitans was isolated from about one-fifth, B intermedius from about one-third, and B gingivalis from 5% of the individuals The present findings suggest that yeasts or enteric rods or pseudomonads occur in the subgingival flora of about one-third of “refractory” adult periodontitis patients We caution against using antibiotics without prior microbiological screening in treating this patient group

296 citations

Journal ArticleDOI
TL;DR: In this article, the authors examined age relationships and mutual interrelationships between cultivable Actinobacillus actinomycetemcomitans and Bacteroides intermedius in 1624 periodontitis patients, 15 to 89 years of age.
Abstract: This study examined age relationships and mutual interrelationships between cultivable Actinobacillus actinomycetemcomitans and Bacteroides intermedius in 1624 periodontitis patients, 15 to 89 years of age. Each subject contributed a pooled subgingival sample, obtained from 3 deep periodontal pockets with paper points. A. actinomycetemcomitans occurred with higher prevalence (74%) and mean recovery (7% in culture-positive patients) in patients less than 25 years old than in adult and geriatric patients (prevalence about 31%; mean recovery about 1%). The organism was detected in 85% of localized juvenile periodontitis patients. B. intermedius was recovered from 45% of the study subjects, averaged about 7% of total isolates in positive patients, and showed no predilection for any age group. As determined from predicted and observed values for A. actinomycetemcomitans and B. intermedius, occurring alone and in combination, no synergistic or antagonistic relationships between the organisms could be delineated with respect to subgingival colonization. The therapeutic implication of these findings is discussed.

200 citations


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TL;DR: Critically discussed the data relevant to each of these seven criteria, with specific emphasis on how this proteinase family could contribute to Candida virulence and pathogenesis.
Abstract: Candida albicans is the most common fungal pathogen of humans and has developed an extensive repertoire of putative virulence mechanisms that allows successful colonization and infection of the host under suitable predisposing conditions. Extracellular proteolytic activity plays a central role in Candida pathogenicity and is produced by a family of 10 secreted aspartyl proteinases (Sap proteins). Although the consequences of proteinase secretion during human infections is not precisely known, in vitro, animal, and human studies have implicated the proteinases in C. albicans virulence in one of the following seven ways: (i) correlation between Sap production in vitro and Candida virulence, (ii) degradation of human proteins and structural analysis in determining Sap substrate specificity, (iii) association of Sap production with other virulence processes of C. albicans, (iv) Sap protein production and Sap immune responses in animal and human infections, (v) SAP gene expression during Candida infections, (vi) modulation of C. albicans virulence by aspartyl proteinase inhibitors, and (vii) the use of SAP-disrupted mutants to analyze C. albicans virulence. Sap proteins fulfill a number of specialized functions during the infective process, which include the simple role of digesting molecules for nutrient acquisition, digesting or distorting host cell membranes to facilitate adhesion and tissue invasion, and digesting cells and molecules of the host immune system to avoid or resist antimicrobial attack by the host. We have critically discussed the data relevant to each of these seven criteria, with specific emphasis on how this proteinase family could contribute to Candida virulence and pathogenesis.

1,111 citations

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TL;DR: A reflection on the results indicates that HA coatings can promote earlier and stronger fixation but exhibit a durability that can be related to the coating quality.
Abstract: The clinical use of plasma-sprayed hydroxyapatite (HA) coatings on metal implants has aroused as many controversies as interests over the last decade. Although faster and stronger fixation and more bone growth have been revealed, the performance of HA-coated implants has been doubted. This article will initially address the fundamentals of the material selection, design, and processing of the HA coating and show how the coating microstructure and properties can be a good predictor of the expected behavior in the body. Further discussion will clarify the major concerns with the clinical use of HA coatings and introduce a comprehensive review concerning the outcomes experienced with respect to clinical practice over the past 5 years. A reflection on the results indicates that HA coatings can promote earlier and stronger fixation but exhibit a durability that can be related to the coating quality. Specific relationships between coating quality and clinical performance are being established as characterization methods disclose more information about the coating.

985 citations

Journal ArticleDOI
TL;DR: This study demonstrated the utility of a 16S rRNA-based PCR detection method for identifying important subgingival microorganisms and indicated a strong association between the study species and periodontitis.
Abstract: A 16S rRNA-based polymerase chain reaction (PCR) detection method was used to determine the prevalence of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Campylobacter rectus, Eikenella corrodens, Porphyromonas gingivalis, Prevotella intermedia. Prevotella nigrescens and Treponema denticola in subgingival specimens of 50 advanced periodontitis, 50 adult gingivitis and 50 pediatric gingivitis subjects. The optimal PCR conditions were determined for each study species. Agarose gel electrophoresis of PCR products from each study species revealed a single band of the predicted size. Restriction enzyme digestion of amplicons confirmed the specificity of the amplification. PCR detection limits were in the range of 25-100 cells. No cross-reactivity with other oral micro-organisms or nonspecific amplification was observed. The prevalence by PCR in advanced periodontitis, adult gingivitis and pediatric gingivitis subjects was 30%, 14% and 14% for A. actinomycetemcomitans, 86%, 18% and 8% for B. forsythus, 74%, 52% and 78% for C. rectus, 80%, 70% and 66% for E. corrodens, 70%, 10% and 14% for P. gingivalis, 58%, 12% and 18% for P. intermedia, 52%, 20% and 22% for P. nigrescens, and 54%, 16% and 16% for T. denticola, respectively. The prevalence was higher in the advanced periodontitis group than in both adult gingivitis and pediatric gingivitis for A. actinomycetemcomitans, B. forsythus, P. gingivalis, P. intermedia, P. nigrescens and T. denticola at P < 0.01, and for E. corrodens at P < 0.05. The prevalence of C. rectus was significantly higher in the advanced periodontitis group than in the adult gingivitis group at P < 0.01. Matching results between PCR and culture occurred in 28% (B. forsythus) to 71% (A. actinomycetemcomitans) of the samples; the major discrepancy occurred in the PCR-positive/culture-negative category. Matching results between PCR and DNA probe methods were found in 84% of the subjects (B. forsythus) and 70% (P. gingivalis). Odds ratio analysis revealed statistically significant positive associations between 17 of the 28 possible combinations (P < 0.01). This study demonstrated the utility of a 16S rRNA-based PCR detection method for identifying important subgingival microorganisms. The results indicated a strong association between the study species and periodontitis. Several previously unreported symbiotic relationships were found between the 8 species tested.

848 citations