Diagnostic utility of specific microbiological markers for periodontal diseases

Specific detection of marker organisms Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans with an immunoassay provided 2 types of useful information directly into private clinical practice: 1) persistence of P. gingivalis in patients undergoing regular treatment allowed rapid identification of pockets requiring further treatment without waiting for measurable progression of lesions and 2) presence of A. actinomycetemcomitans in adults at any stage of diagnosis or treatment identified patients who may prove to have difficult-to-manage periodontitis. We made these findings in 253 patients (234 in specialist periodontal practices [F-ME 55; MHM 179] and 19 in general dental practice [EWM]). The search for useful diagnostic markers overlaps only partly with the search for periodontal pathogens. The P. gingivalis marker and the A. actinomycetemcomitans marker identify 2 different patterns of infection that appear to reflect 2 different underlying problems. Demonstration of pocket-dependent infection with P. gingivalis in treated patients provides an outcome marker for sites not converting to marker-negative sites at detection levels of the immunoassay. This information facilitates selection of sites and patients requiring adjustment of treatment regimens. Detection of A. actinomycetemcomitans in adult patients is significantly associated with periodontitis characterized as refractory. Positive identification of A. actinomycetemcomitans with the immunoassay supports clinical decision-making by drawing attention to adult patients who require closer monitoring and intensive persistent treatment. Successful application of immunoassay detection of microbiological markers is based on continuous patient monitoring to support clinical decisions; it does not replace careful clinical judgment.     

Nonsteroidal anti-inflammatory agents: potential modifiers of periodontal disease progression

The most recent studies of NSAIDs as potential modifiers of periodontal disease progression are reviewed. These studies indicate that NSAIDs have the ability to alter or control the progression of periodontal disease. Reductions in gingival inflammation and in bone loss have been observed following the administration of various NSAIDs. In some cases, bone gain has been achieved. More research is required to determine the possible long-term side effects associated with the chronic usage of NSAIDs, as well as to achieve consensus on the most effective drug for the control of periodontal disease. Until this occurs, and this application of NSAIDs receives government approval, the use of these drugs to control periodontal disease is not recommended.     

Pharmacologic management of periodontal diseases using systemically administered agents

Since the establishment of bacteria-laden plaque as a causative agent in gingivitis, the search for specific bacteria that induce different types of periodontitis has generated extensive research. In contrast to many other microbial-induced disorders, the specific periodontal pathogen(s) has not been identified to date. Therefore, the search for an effective systemic agent to prevent the loss of attachment through the selective reduction of known periodontal pathogens has remained elusive. It is not surprising then that antibiotics are not used solely to manage periodontal diseases but rather as an adjunct to the mechanical débridement of root surfaces in select periodontal diseases. Further, the sole use of antibiotics in patients with adult periodontitis (or those who exhibit signs of inflammation but are periodontally stable) has shown little benefit and only increases the chance of microbial resistance to antibiotics. Despite these limitations, considerable progress in antibiotic therapy has delivered regimens that enhance the effectiveness of conventional therapy. In contrast to traditional antimicrobial therapy, new treatment modalities have begun to focus on modulating the responses of host cells to bacteria rather than modulating only the bacteria. Current drugs used to regulate host cells inhibit the cyclooxygenase pathway, reduce the activity of metalloproteinases, or inactivate bone resorptive cells (see Table 1). Although these drugs offer great potential to modulate a variety of mammalian cells, a notable and consequential limitation of these agents is a lack of specificity. Inflammation, bone metabolism, and connective tissue metabolism are two-edged swords; all are necessary for the homeostasis of the tissue, but some or all may also be involved in the pathologic destruction of that same tissue. Hence, drugs that inhibit destruction of the connective tissue in one site of the periodontium also interfere with wound healing at another. As a result of these limitations, the efficacy, safety, and cost-effectiveness of the long-term use of these agents is unknown. Preliminary results of treatment with these drugs are promising, and future generations of host-modulating drugs will provide clinicians with additional agents to help improve the success rate of periodontal treatment for patients. Antibiotics remain an important adjunctive therapy in the treatment of periodontal diseases, and the use of host modulating drugs as supplemental agents in the management of periodontal diseases continues to grow. As more knowledge is gained about the causes of periodontal diseases, new drugs that are potent, effective, site specific, and safe can be delivered at optimal times by simply having the patient take a few tablets. Considering the dramatic progress in the past decade in understanding the cause and pharmacologic management of periodontal diseases, the twenty-first century holds great promise for the development of magic bullets.     

Subgingival microbiota in adult Chinese: prevalence and relation to periodontal disease progression

The "checkerboard" Dna-Dna hybridization technology was used to study the epidemiology of 18 microbial species associated with various states of periodontal health and disease, in a sample of 148 Chinese subjects never exposed to systematic dental therapeutic intervention, aged 30 to 39 and 50 to 59 years. Our aims were to: 1) describe the prevalence of these microorganisms; 2) correlate the microbiological and clinical profiles of the subjects; and 3) examine the association between the microbiological variables and the longitudinal changes of periodontal status that occurred over a preceding 10-year period. A maximum of 14 subgingival samples were obtained from each subject-1,864 in all. The frequency of occurrence of the 18 species examined was high in this Chinese population, on both the subject and the tooth site level. However, all species were not found equally capable of reaching high numbers in the subgingival samples and, as a rule, colonized heavily only limited proportions of tooth sites within each mouth. There was a profound increase of certain species such as Porphyromonas gingivalis, Treponema denticola, and Bacteroides forsythus in deep pockets or progressing sites. Multivariate techniques using the subgingival profile could effectively discriminate between deep/shallow pockets and progressing/ stable tooth sites. The microbiological variables showed an enhanced discriminating potential when classifications were performed on the individual subject level. Colonization by P. gingivalis, B. forsythus, Campylobacter rectus, and T. denticola at levels exceeding certain thresholds entailed a significantly increased probability (odds ratios > 4) for an individual subject to harbor deep pockets or progressing tooth sites.     

Alterations of neutrophil L-selectin and CD18 expression by tobacco smoke: implications for periodontal diseases

The treatment and prevention of osteoporosis in women represents an unresolved problem. The aim of this systematic review was to determine whether exercise can be useful in this context. Various literature searches identified 21 randomised controlled trials on the subject. These are highly diverse in more than one respect. Collectively, however, the strongly suggest that regular physical exercise can reduce the risk of osteoporosis and delay the physiological decrease of bone mineral density. It is concluded that regular exercise for women of practically all ages is well advised.     

Serum antibody opsonic activity against Actinobacillus actinomycetemcomitans in human periodontal diseases

Actinobacillus actinomycetemcomitans is frequently associated with severe periodontitis. Many periodontitis patients have elevated levels of serum IgG antibodies to A. actinomycetemcomitans, but the role of these antibodies is unknown. This study evaluated the functional capacity of anti-A. actinomycetemcomitans IgG antibody to enhance phagocytosis of A. actinomycetemcomitans by polymorphonuclear leukocytes. Chemoluminescence assays were done using sera from 64 subjects, 61 of whom had severe periodontitis; results were compared with the subject's anti-A. actinomycetemcomitans IgG titer and avidity. There was a strong correlation between chemoluminescence and antibody log titer (P < .00001) and a weak correlation between chemoluminescence and antibody avidity (P < .05). The results support the hypothesis that anti-A. actinomycetemcomitans IgG antibodies are important in promoting phagocytosis and killing of A. actinomycetemcomitans. Subjects who develop high levels of highly avid antibodies against A. actinomycetemcomitans may have greater resistance to continued or repeated infection by this pathogen.     

New findings on pathogenic mechanisms of collagen fiber damage during development of periodontal diseases]

This paper reviews new knowledge on collagen destruction of the periodontium during development of periodontal diseases. Numerous clinical and experimental studies reveal important data in regard to recognition of these pathogenetic mechanisms. Two of them are described: intracellular-not depending on collagenase and extracellular-depending on collagenase. Which of these mechanisms is more important or what their concrete relationship is like, is still unknown.     

The role of risk factors in the development of a hemoendothelial imbalance in periodontal diseases

The given piece investigates the spreading of parodontitis in Armenia in linkage with such factors as diabetes, arthritis, stresses which have proved to have their influence on leukocyte-endothelial balance. The spreading of various forms of parodontitis was revealed with almost 70% of the examined among Armenian population. For patients with diabetes, arthritis and its combination with arterial hypertension this indicator grew up to 90%. The number of patients with parodontitis has especially increased. A drastic increase of markers of endothelia disorganization was observed among these patients in comparison with all the other examined groups. The growth of the levels of the investigated markers remains dependent on the seriousness of the generalized paradontitis.     

Factors associated with severity and disease progression in chronic hepatitis C

BACKGROUND/AIMS: Chronic hepatitis C appears to have a highly variable natural course with 20% of patients developing cirrhosis within 20 years, while the majority of them run a relatively mild course. We studied the relationships of epidemiological, biochemical and virological features with histological severity (grade) and liver disease progression (stage). METHODOLOGY: Liver histology, serum HCV RNA level and HCV genotype were determined in a well-defined cohort of 152 consecutive (100 males, 52 females) patients with chronic hepatitis C. RESULTS: Patients with minimal or mild chronic hepatitis were significantly younger than those with moderate or severe chronic hepatitis (mean age: 41.1 vs 49.5 years respectively, p=0.003). On the other hand, patients with no or mild fibrosis compared to those with moderate or severe fibrosis and to those with cirrhosis were significantly more frequently males (73%, 64% and 43%, p=0.01), parenteral drug users (36%, 11% and 11%, p=0.01) and infected with other than 1b genotype (86%, 52% and 33%, p<0.0001), significantly younger (mean age: 37, 48 and 58 years, p<0.0001) and had significantly lower HCV RNA levels (geometric mean: 6.9, 19.2 and 17.5 x 10(5) eq/ml, p=0.007). Multivariate analysis showed that stage was significantly related only to patient age (p<0.0001), HCV genotype (p=0.0025) and HCV RNA level (p=0.044). CONCLUSIONS: In chronic hepatitis C, histological severity seems to be associated only with patient age, while progression of the disease is mainly associated with patient age, HCV genotype and viremia level.     

Risk indicators for harboring periodontal pathogens

Mutations in the Agr locus of Arabidopsis thaliana impair the root gravitropic response. Root growth of agr mutants is moderately resistant to ethylene and to an auxin transport inhibitor. Vertically placed agr roots grow into agar medium containing IAA or naphthalene-1-acetic acid, but not into medium containing 2,4-D. Positional cloning showed that AGR encodes a root-specific member of a novel membrane-protein family with limited homology to bacterial transporters.     

Conversion enzyme inhibitors against the progression of renal and vascular diseases: yes but again

p21WAF1/CIP1 is a potent, tight-binding inhibitor of Cdks which is induced by the wild-type p53 gene. We examined p21WAF1/CIP1 mRNA expression in 16 surgically excised human colorectal tumor and nontumor tissues using Northern blot analysis with reference to the identification of p53 gene mutation. p53 gene mutation was detected in six tumor tissues but not in the other 10 using the PCR-SSCP method. The p21WAF1/CIP1 mRNA level was lower in tumor tissues than in the corresponding nontumor tissues. The mean expression level of p21WAF1/CIP1 mRNA was lower in tissues in which the p53 gene mutation was detected than in those in which it was not, although the difference was not significant. The relative p21WAF1/CIP1 mRNA expression level was significantly higher in the tumors with liver metastases than in those without. These results suggest that the p21WAF1/CIP1 mRNA expression level, which might be a indicator of colorectal cancer malignancy, is suppressed in human colorectal tumor tissues compared with the corresponding nontumor tissues and that the wild-type p53 gene is one of the factors inducing p21WAF1/CIP1 mRNA expression.     

Outcome variables for the study of periodontal regeneration

The most reliable outcome variable for assessing periodontal regeneration is human histology; however, the morbidity associated with this technique makes it feasible only in isolated case studies designed to prove that a drug, device, or technique is capable of regenerating the lost periodontium including bone, cementum, and functionally oriented periodontal ligament. In the absence of this genuine variable, other "surrogate" variables must be used. Of these, measurement of new bone is the primary alternative. Direct bone measurements, including linear and volumetric assessment, are by far the best tools; however, the need for a second surgical procedure is a definite drawback of this technique. To overcome this problem, other outcomes have been employed: sounding bone measurements is a less invasive method, albeit it is also less accurate. Another tool that has been tested extensively is radiographic analysis. Conventional radiography is not useful in most regenerative trails where minimal or no crestal changes occur. The use of standardized radiographs and image processing techniques to measure alveolar bone changes has not significantly enhanced the applicability of this method. Digital subtraction radiography (DSR) offers some improvement over previous techniques; however, the correlation between the magnitude of clinical bone changes and changes in the digital image is yet to be substantiated. Other variables have been successfully used in regenerative studies. These include clinical attachment level changes, change in probing depth, and gingival recession. The information derived from these variables, especially attachment level changes, supplement and substantiate the direct bone measurements. Other variables that may be monitored are those associated with plaque formation, periodontal pathogens and gingival inflammation; while not direct measures of regeneration, these variables are likely to affect future prognosis and treatment stability. In summary, direct bone measurements are the most ideal surrogate outcome variable, although clinical attachment level measurements are commonly used in large-scale regenerative clinical trials. Clinical response may be assessed at different time intervals; however, the endpoint measurements for regenerative studies should be taken at least 12-months postoperatively.