Assessment of cytotoxic and antimicrobial activity of selected gingival haemostatic agents - in vitro study.

PURPOSE: The present research aimed to determine whether and how the aluminium chloride - based materials affect the cell line of the bacterial line and fungi. METHODS: Cytotoxicity of haemostatic astringents: Alustat (liquid), Alustat (gel), Alustat (foam), Alustin, Hemostat, Racestyptine and Traxodent containing AlCl3 was conducted on L929 cell line with the use of MTT and SRB assays. The antimicrobial activity (CFU and MIC) against C. albicans, S. mutans, L. rhamnosus was determined. RESULTS: In the MTT results, cell viability for all agents were very low. In SRB, the lowest cytotoxicity was demonstrated for Hemostat and Alustat (foam), Traxodent and Racestyptine. Total reduction of the CFU of S. mutans was observed. Alustat (gel) and Alustat (liquid) completely inhibited the growth of C. albicans, S. mutans and L. rhamnosus. CONCLUSIONS: The viability of L929 cells obtained in the SRB assay is more reliable than that obtained in the MTT assay, in the case of gingival haemostatic agents.

Assessment of periodontitis and its role in viridans streptococcal bacteremia and infective endocarditis.

OBJECTIVES: To evaluate the role of periodontitis in viridans group streptococci (VGS) bacteremia and infective endocarditis (IE). METHODS: A total of 200 subjects including two groups. Group A- 34 subjects undergoing tooth extraction with periodontitis, 46 subjects undergoing tooth extraction without periodontitis and 40 healthy controls. Group B: 40 confirmed cases of IE (17 with and 23 without periodontitis) and 40 healthy controls. Subgingival plaque and blood samples were obtained and processed by standard procedures. RESULTS: A total of 53 blood samples (66.25%) yielded positive cultures after tooth extraction. The relationship between the presence of periodontitis and a positive blood culture was significantly higher (p=0.05) for tooth extraction cases with periodontitis (79.40%) than tooth extraction cases without periodontitis (56.50%). Periodontitis was observed in 42.5% of IE cases. Out of the 40 patients of IE, the blood samples yielded 40 different isolates, majority were viridans streptococci 15 (37.5%) and staphylococci nine (22.5%). No statistically significant difference was observed between the subgingival plaque and blood isolates of periodontitis in both the groups, indicating similarity of biotypes of viridans streptococci isolated from the blood and the subgingival plaque. Similarity was also observed between the antibiogram profiles of viridans streptococci from both the groups. CONCLUSIONS: Periodontitis enhances viridans streptococcal bacteremia and may be a potential risk factor for IE.

Assessment of Photodynamic Inactivation against Periodontal Bacteria Mediated by a Chitosan Hydrogel in a 3D Gingival Model.

Chitosan hydrogels containing hydroxypropyl methylcellulose (HPMC) and toluidine blue O were prepared and assessed for their mucoadhesive property and antimicrobial efficacy of photodynamic inactivation (PDI). Increased HPMC content in the hydrogels resulted in increased mucoadhesiveness. Furthermore, we developed a simple In Vitro 3D gingival model resembling the oral periodontal pocket to culture the biofilms of Staphylococcus aureus (S. aureus), Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), and Porphyromonas gingivalis (P. gingivalis). The PDI efficacy of chitosan hydrogel was examined against periodontal biofilms cultured in this 3D gingival model. We found that the PDI effectiveness was limited due to leaving some of the innermost bacteria alive at the non-illuminated site. Using this 3D gingival model, we further optimized PDI procedures with various adjustments of light energy and irradiation sites. The PDI efficacy of the chitosan hydrogel against periodontal biofilms can significantly improve via four sides of irradiation. In conclusion, this study not only showed the clinical applicability of this chitosan hydrogel but also the importance of the light irradiation pattern in performing PDI for periodontal disease.

Improved, low-cost selective culture medium for Actinobacillus actinomycetemcomitans.

Actinobacillus actinomycetemcomitans is considered to be one of the major oral putative pathogens, especially in cases of juvenile periodontitis. This microorganism requires nutritionally complex media for growth, and therefore the media for its primary isolation usually include blood agar or serum in their base. In this study we present a new medium, Dentaid-1, which improves the detection of A. actinomycetemcomitans in periodontal samples. In its composition, blood and serum have been omitted, hence reducing its cost and making it a more restrictive medium against the growth of other microorganisms with high nutritional requirements. The growth yields of pure cultures of the bacteria on Dentaid-1 were comparable to those on nonselective blood agar. Moreover, clinical efficacy was evaluated in subgingival samples from 77 subjects with adult periodontitis. Dentaid-1 detected A. actinomycetemcomitans in 24 subjects, while a previously described tryptic soy-serum-bacitracin-vancomycin agar detected the microorganism in only 19 subjects (79.1%). Dentaid-1 is a low-cost, noninhibitory formula for the improved diagnosis and monitoring of patients subgingivally infected by this important oral putative pathogen.

Risk assessment for periodontal diseases.

Assessment of risk for periodontitis is still in its infancy. Nevertheless, a sufficient amount of dependable information exists to begin using risk assessment in the day to day practice of dentistry. The purpose of this paper is to summarise existing information about risks for periodontitis in a manner that is useful to practitioners. Risks for moderate to severe periodontitis that have been identified include cigarette smoking, advancing age, diabetes mellitus and certain other systemic conditions. These include, osteoporosis and HIV infection and conditions such as irradiation and immunosuppressive drugs that interfere with normal host defences, specific pathogenic bacteria in the subgingival flora, microbial deposits and poor oral hygiene status, bleeding on probing, previous disease experience and severity, and inheritance. Some risks such as pathogenic bacteria in the subgingival flora are strongly linked to causation of the disease while others such as bleeding on probing may indicate enhanced risk for future disease but are not known to be involved in causation and still others such as advancing age may be background factors that enhance susceptibility. While some risks such as cigarette smoking can be modified to lower the level of risk, others such as ageing are immutable and cannot be modified but need to be considered in overall risk assessment. A goal of periodontal diagnosis, treatment planning and therapy is to lower risk for future periodontal deterioration to the maximal extent. One approach to achieving this goal is described.

[The comprehensive assessment of studies of the microbiological and cytological indices of the implant-epithelial area]. / Kompleksnaia otsenka issledovanii mikrobiologicheskikh i tsitologicheskikh pokazatelei implantoépitelial'noi zony.

Microbiological and cytological study of the subgingival deposit at the site of introduction of intraosseous cylindrical nickelide-titanium dental implants and comparison of the findings with similar values for the adjacent teeth showed that such studies help assess the status of the implant-epithelial zone.

Evidence for genetic control of changes in f-actin polymerization caused by pathogenic microorganisms: in vitro assessment using gingival fibroblasts from human twins.

Attachment to and migration upon a substratum, as well as other functions of connective tissue cells, are regulated mainly by cytoplasmic structural proteins, particularly filamentous actin (f-actin). Pathogenic microorganisms exert negative effects on cytoskeletal proteins. In the present study, normal gingival fibroblasts from 10 sets of human twins (6 fraternal, DZ; 4 identical, MZ) were exposed to soluble extracts from Porphyromonas gingivalis or Fusobacterium nucleatum, then f-actin was stained using FITC-labeled phalloidin. Cells were examined under fluorescence, and a computer-assisted image analyzer quantitated f-actin polymerization as fluorescence intensity on a per-cell basis. Intraclass correlation coefficients for f-actin in MZ/MZ vis-a-vis DZ/DZ paired cell cultures were determined to assess the possible heritability of responses to the microorganism preparations. F-actin labeling was significantly different between control cultures and those exposed to the extracts. Both F. nucleatum and P. gingivalis effected f-actin and fibroblast morphology. When the data were adjusted for gender and age effects, and for differences in control f-actin levels, fibroblasts from MZ twin pairs were moderately similar in both absolute and relative responses to bacterial challenges; cells from DZ twins showed little similarity when response was measured on the absolute scale, and moderate similarity using the relative scale.

Assessment of serum antibody patterns and analysis of subgingival microflora of members of a family with a high prevalence of early-onset periodontitis.

In a study of members of a large family with a high prevalence of early-onset periodontitis, we sampled the subgingival microflora and characterized 40 isolates from each sample. We surveyed serum samples by enzyme-linked immunosorbent assay for antibodies reacting with any of a panel of 21 periodontal bacteria. The mother and 7 of her 13 children had early-onset periodontitis. Bacteroides gingivalis was not detected in the subgingival flora of any affected or unaffected family member, and Actinobacillus actinomycetemcomitans was isolated from only one affected child. Capnocytophaga ochracea was isolated from five of seven affected children and from none of their normal siblings. We found no significant differences among the floras from family members who had rapidly progressive, juvenile, and prepubertal forms of periodontitis. Elevated levels of serum antibody reacting with one or more of the bacteria tested were found in all family members with disease, but in only one periodontally normal family member. Both children with prepubertal periodontitis had antibodies reacting with C. sputigena, a species not found in their subgingival floras, but with none of the other bacteria tested. All remaining affected family members had antibodies to one or more serotypes of A. actinomycetemcomitans, and four had antibodies reacting with additional bacteria, including C. sputigena, Eikenella corrodens, Fusobacterium nucleatum, and Haemophilus aphrophilus. Sera from patients contained antibodies specific for putative periodontal pathogens not found in their pocket flora, and conversely, putative periodontal pathogens for which no serum antibodies were found frequently comprised a large proportion (10% or more) of the pocket flora. In no case were both the bacterium and its antibody found. These observations are suggestive of sequential infection in the early-onset forms of periodontitis and of induction of protective immunity against reinfection by the same microorganism.