Browsing by Subject "Dental Plaque"

Now showing 1 - 6 of 6
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    Binding of oral veillonella species to saliva-coated hydroxyapatite
    (1993) Wu, Sonya L.; Hughes, Christopher V.; Gregory, Richard L.; Sanders, Brian J.; Bowman, Dennis E.; Avery, David R.
    Veillonella spp. are found in high numbers in the mouth in dental plaque and on the mucosa. Veillonellae utilize lactic acid for their metabolic needs. A symbiotic relationship between Veillonellae and other oral bacteria, including a nutritional relationship with some streptococci, has been demonstrated both in vitro and in vivo. Thus, Veillonellae may protect the host from dental caries. Adherence is the initial step in bacterial colonization of oral surfaces. Recent evidence suggests that certain oral bacteria express molecules (adhesins) on their cell surface, which recognize receptors on other oral bacteria and/or in salivary pellicle. It has been previously demonstrated that Veillonella spp. bind avidly to Streptococcus. spp. found in subgingival plaque. The present study investigated the ability of V. atypica PK1910 to bind to saliva-coated hydroxyapatite (SHA), a model for adherence to the salivary pellicle. The results show that there was statistically significant enhanced binding of Veillonella atypica PK1910 to saliva-coated hydroxyapatite beads. (p< 0.05) Three classes of coaggregation-defective mutants of V. atypica PK1910 were tested for their ability to bind to SHA. Interestingly, they did not demonstrate any enhanced binding to saliva-coated hydroxyapatite beads. Heating of PK1910 did not effect binding to SHA. In contrast, protease treatment of the veillonella cell surface inactivated binding. Therefore, it appears that V. atypica PK1910, in addition to binding to oral Streptoccoccus spp. in dental plaque, may also colonize the tooth surface by binding directly to the salivary pellicle. It appears that a distinct heat stable protein may mediate this binding to SHA.
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    A clinical television evaluation of plaque formation in children
    (1969) Eichel, Ronald Andrew, 1941-
    The purpose of this study was to determine the rate of plaque formation in children and its relationship to their periodontal and caries indices and to evaluate a television area measurement instrument. Plaque formation at 6-, 24-, 48-, and 96-hour intervals was observed in 56 children aged 8 through 12 to establish the rapidity of its reformation after a thorough dental prophylaxis. The plaque was recorded with disclosing agents and oriented Polaroid photographs and measured by newly developed television and electronic area measurement instrumentation which proved to be highly reliable. The presence of caries and periodontal disease was then correlated with the amount of plaque recorded at each observation period. A high correlation was found between the Anterior P-M-A and the Periodontal Index. No significant correlations were found between the periodontal indices and the DMFs scores or with the amount of plaque present and the DMFs scores. Seventy-seven per cent of the children displayed measurable amounts of plaque just 6 hours after a thorough dental prophylaxis. In comparing the amount of plaque formed by these children with results reported from similar studies conducted on adults, it is apparent that children in this age group form more plaque in less time than adults. A significant correlation was found between the amount of plaque present and the periodontal indices at the 48-hour examination.
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    Interactions of starch hydrolysis products with oral bacteria
    (1987) Glor, Elizabeth Anne Buehrer
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    Investigations of the anti-caries potential of fluoride varnishes
    (2015-11-12) Al Dehailan, Laila Adel; Martinez-Mier, Esperanza Angeles; Lippert, Frank; Soto-Rojas, Armando E.; González-Cabezas, Carlos; Stelzner, Sarah
    The majority of currently marketed fluoride varnishes (FV) have not been evaluated for their effectiveness in preventing dental caries. Fundamental research on FVs and how different formulations affect adherence to teeth, fluoride release into saliva and uptake by teeth is virtually non-existent. The objective of this work was to investigate the anti-caries potential, measured as fluoride release into saliva, change in surface microhardness of early enamel caries lesions, and enamel fluoride uptake, of multiple commercially available FVs. We have found that FVs differed in their release characteristics, rehardening capability, and ability to deliver fluoride to demineralized lesions. In addition to our in vitro work, we have conducted a clinical study that aimed to compare saliva and plaque fluid fluoride concentrations following the application of three commercially available FV treatments at predetermined post application time points. We also investigated the change in fluoride concentration in saliva and plaque fluid fluoride from baseline to each post application predetermined time point. We found that FVs varied in their release of fluoride into saliva and plaque fluid but shared common trends in release characteristics. The outcomes of our in vitro and in vivo investigations demonstrate a great variation in anti-caries potential of FVs. This may be attributed to different compositions and physical properties of the tested FVs.
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    The systemic inflammatory response to dental plaque
    (2010) Wahaidi, Vivian Y.; Kowolik, Michael J.; Galli, Dominique M.; Dowsett, Sherie A.; Allen, Bradley L.; Gregory, Richard L.
    Introduction: Bacteremia involving oral bacteria and the systemic inflammatory responses are mechanisms that could causally link oral and systemic diseases. Objective: To use an experimental gingivitis model (EGM) in 2 clinical studies to 1) examine the systemic inflammatory responses to dental plaque, and assess racial differences in these responses; 2) determine whether dental plaque accumulation causes bacteremia and subsequent systemic responses following toothbrushing. Additionally, a laboratory study was conducted to examine the interaction between circulating human neutrophils and Fusobacterium nucleatum. Methods: For both clinical studies, healthy adults, aged 18-31 years, were recruited. In the first study, black and white, males and females participated in a 21-day EGM; in the second study, white adults participated in a 7-day EGM. In both studies, subjects visited the clinic weekly for: 1) measurement of the plaque index (PI) and gingival index (GI); 2) collection of peripheral blood samples to evaluate systemic markers of inflammation. In the second study, to analyze bacteremic episodes during the experimental phase, peripheral blood samples were collected at baseline and at 0.5, 5, and 30 minutes post-toothbrushing. In the laboratory study, interactions between F. nucleatum and circulating neutrophils were examined using a luminol-enhanced chemiluminescence assay. Results: During the experimental phases of both clinical studies, PI and GI increased (p<0.05) with a correlation between PI and GI ≥0.79. In the first study, dental plaque accumulation resulted in a systemic response that manifested as changes (p<0.05) in the level of inflammatory markers, hematologic factors, markers of lipid metabolism, and markers of metabolic change. This systemic response differed between individuals of different gender and race. In the second study, bacteremic episodes and changes in hematologic factors were observed post-toothbrushing during the experimental phase. Activation of neutrophils with F. nucleatum, in the laboratory study, increased the levels of neutrophil chemiluminescence (p<0.05). Conclusions: Overall, the findings of these investigations may shed light on the mechanistic pathways by which oral infection may impose risk for systemic diseases and provide some evidence to support a possible causal association between oral and systemic diseases. The clinical significance of this in systemic inflammatory diseases requires further investigation.