| 1. |
- Chávez de Paz, Luis, 1974, et al.
(författare)
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Response to alkaline stress by root canal bacteria in biofilms. : Viability and mechanisms of response to alkaline stress by selected root canal bacteria.
- 2007
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Ingår i: International endodontic journal. - : Wiley. - 0143-2885 .- 1365-2591. ; 40:5, s. 344-55
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To determine whether bacteria isolated from infected root canals survive alkaline shifts better in biofilms than in planktonic cultures. METHODOLOGY: Clinical isolates of Enterococcus faecalis, Lactobacillus paracasei, Olsenella uli, Streptococcus anginosus, S. gordonii, S. oralis and Fusobacterium nucleatum in biofilm and planktonic cultures were stressed at pH 10.5 for 4 h, and cell viability determined using the fluorescent staining LIVE/DEAD BacLight bacterial viability kit. In addition, proteins released into extracellular culture fluids were identified by Western blotting. RESULTS: Enterococcus faecalis, L. paracasei, O. uli and S. gordonii survived in high numbers in both planktonic cultures and in biofilms after alkaline challenge. S. anginosus, S. oralis and F. nucleatum showed increased viability in biofilms compared with planktonic cultures. Alkaline exposure caused all planktonic cultures to aggregate into clusters and resulted in a greater extrusion of cellular proteins compared with cells in biofilms. Increased levels of DnaK, HPr and fructose-1,6-bisphosphate aldolase were observed in culture fluids, especially amongst streptococci. CONCLUSIONS: In general, bacteria isolated from infected roots canals resisted alkaline stress better in biofilms than in planktonic cultures, however, planktonic cells appeared to use aggregation and the extracellular transport of specific proteins as survival mechanisms.
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| 2. |
- Chávez de Paz, Luis, 1974, et al.
(författare)
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Streptococci from root canals in teeth with apical periodontitis receiving endodontic treatment.
- 2005
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Ingår i: Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. - : Elsevier BV. - 1528-395X .- 1079-2104. ; 100:2, s. 232-41
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The object of this study was to investigate the diversity among streptococcal species isolated from root canals in conjunction with endodontic therapy and to characterize their production of extracellular proteins. STUDY DESIGN: Consecutive root canal samples (RCS) taken as bacteriological controls during root canal treatment of teeth with apical periodontitis were analyzed in a total of 100 clinical cases. Bacteria were isolated and classified by selective media and gas liquid chromatography. Streptococcal strains were identified by carbohydrate fermentation, hydrolysis of aesculin/arginine, and production of enzymes. Releases of extracellular proteins by streptococci and Enterococcus spp in fluid culture media were examined with SDS-PAGE and 2-dimension gel electrophoresis (2 DE). Extracellular proteins produced were quantified and qualitatively analyzed. Specific proteins were targeted with Western immunoblot assays. Comparisons were made with type strains. RESULTS: Of a total of 241 bacterial strains recovered in the first samples submitted, Streptococcus gordonii, S anginosus, and S oralis were the most frequently isolated streptococci. In 49 of 89 resubmitted samples showing bacterial growth, S gordonii and S oralis still predominated among streptococci. Other common bacterial isolates were Enterococcus spp, Lactobacillus paracasei, and Olsenella uli. Quantitative and qualitative differences in extracellular protein production were observed among clinical isolates and laboratory streptococcal strains. In similar conditions for growth, S intermedius, S anginosus, S oralis, and S gordonii were strong producers of extracellular proteins (>3.0 microg/mL), while Enterococcus spp and S mutans were weak. Whole cell protein extracts showed a different profile from that of extracellular proteins. The chaperone protein DnaK was recognized to be produced extracellularly by S gordonii, S oralis, S anginosus, and S parasanguis. CONCLUSIONS: Being strong producers of extracellular proteins and by virtue of common presence in teeth undergoing endodontic therapy, S gordonii, S anginosus, and S oralis may be of pathogenic significance in posttreatment apical periodontitis.
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| 3. |
- Axelsson, Susanna, et al.
(författare)
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Economic aspects of the detection of occlusal dentine caries.
- 2009
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Ingår i: Acta odontologica Scandinavica. - : Informa UK Limited. - 1502-3850 .- 0001-6357. ; 67:1, s. 38-43
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate the cost of true-positive occlusal dentine caries detection in permanent molars assessed by: (I) visual-tactile examination, (II) visual-tactile examination combined with bitewing radiographs, and (III) selective radiographic examination of patients with lesions detected clinically. A second aim was to analyse the different strategies when the costs of the subsequent restorative care are considered. METHODS: A model analysis was applied owing to the lack of original articles. Sensitivity and specificity were calculated from a systematic review and included in vitro and in vivo studies of medium and high quality. The direct costs for examinations and restorative care were extracted from the costs of the Public Dental Service in Sweden (2006). RESULTS: The diagnostic costs per true-positive finding were dependent on the occurrence of occlusal caries and increased with decreasing prevalence. The strategy by which radiographs were exposed selectively on the basis of findings from visual-tactile examination resulted in higher initial costs compared with the first and second strategies. When the costs of the subsequent restorative care were added, the selective strategy was most beneficial by up to 26% savings per true-positive diagnosis. However, with this selective strategy, more cases of true-positive dentine caries were assumed would remain undetected as compared with the combined strategy with visual-tactile examination and radiographs for all. CONCLUSIONS: The cost for a true-positive caries diagnosis was inversely related to caries occurrence, and different diagnostic strategies may display contrasting outcomes when subsequent restorative care is taken into account.
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| 4. |
- Buduneli, Nurcan, et al.
(författare)
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Evaluation of the relationship between smoking during pregnancy and subgingival microbiota.
- 2005
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Ingår i: Journal of clinical periodontology. - 0303-6979. ; 32:1, s. 68-74
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Numerous studies have shown that smoking negatively affects periodontal health. Hormonal changes, which occur during pregnancy have also been reported to have adverse effects on the periodontal tissues or indirectly through alterations in the subgingival bacterial flora. At present, no knowledge exists concerning possible effects of smoking on the composition of subgingival plaque in pregnancy. The purpose of the present study was to evaluate the effects of smoking during pregnancy on the subgingival plaque bacteria most commonly associated with periodontal disease. METHODS: A total number of 181 women were examined within 72 h post-partum. Smoking status was recorded by means of a self-reported questionnaire and the study population was divided into three groups; non-smokers, light smokers, and heavy smokers. In each woman, two subgingival plaque samples were obtained from mesio- or disto-buccal aspect of randomly selected one molar and one incisor tooth by sterile paperpoints. Clinical periodontal recordings comprising presence of dental plaque, bleeding on probing (BOP), and probing pocket depth (PPD) were performed at six sites per each tooth at all teeth. Plaque samples were analysed by checkerboard DNA-DNA hybridization with respect to 12 bacterial species. In all analyses, the individual subject was the computational unit. Thus, mean values for all clinical parameters were calculated and bacterial scores from each individual sample were averaged. Statistical methods included chi2 test, Kruskal-Wallis test and Mann-Whitney U-test. RESULTS: Mean ages were similar in the study groups. Plaque, BOP and PPD recordings were lower in the heavy-smoker group, but the differences were not statistically significant (p>0.05). The detection rates and bacterial loads of the specific subgingival bacteria exhibited no significant differences between the groups. No correlation could be found between smoking status and detection rates and bacterial loads of various bacterial species. CONCLUSION: The present findings suggest that smoking during pregnancy does not have a significant effect on the composition of subgingival plaque bacteria.
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| 5. |
- Buduneli, Nurcan, et al.
(författare)
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Periodontal infections and pre-term low birth weight: a case-control study.
- 2005
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Ingår i: Journal of clinical periodontology. - 0303-6979. ; 32:2, s. 174-81
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Pre-term delivery of low-birth-weight infants [pre-term low birth weight (PLBW)] remains a significant public health issue and a major cause of neonatal death and long-term health problems. There is a growing consensus that infections remote from fetal-placental unit may influence PLBW infants. Recent studies have suggested that maternal periodontal disease may be an independent risk factor for PLBW. The purpose of the present study was to evaluate the possible link between periodontal infections and PLBW by means of clinical and microbiological data in post-partum women with low socioeconomic level. METHODS: Clinical periodontal recordings comprising dental plaque, bleeding on probing, probing pocket depth and gingival recession were performed (six sites/tooth) in a total number of 181 women (53 cases and 128 controls) within 3 days post-partum. Subgingival plaque samples from mesio-or disto-buccal aspect of randomly selected one first molar and one incisor tooth have been obtained by paperpoints and were analysed by checkerboard DNA-DNA hybridization with respect to 12 bacterial species. In all analyses, the individual subject was the computational unit. Thus, mean values for all clinical parameters were calculated and bacterial scores from each individual sample were averaged. Statistical methods included Student's t-test, Fisher's exact test/chi(2) test, and multiple logistic regression analysis. RESULTS: The cases have gained significantly less weight during the pregnancy than did the controls (p<0.05). There were no statistically significant differences between the cases and controls with regard to the dental and periodontal parameters and the values of clinical periodontal recordings were found to be very similar (p>0.05). Mean and median scores (bacterial loads) of Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Actinobacillus actinomycetemcomitans, and Streptococcus intermedius in the subgingival plaque sampling sites were significantly higher in the controls than in the cases (p<0.05). The occurrence rates of P. intermedia, Fusobacterium nucleatum, Peptostreptococcus micros, Campylobacter rectus, Eikenella corrodens, Selenomonas noxia and S. intermedius were higher in the cases compared with the controls, but the differences were not statistically significant (p>0.05). According to the model created by the multiple logistic regression analysis, P. micros and C. rectus were found to significantly increase the risk of PLBW (p<0.01 and p<0.05 respectively), while P. nigrescens and A. actinomycetemcomitans decreased this risk (p<0.01). CONCLUSION: The present findings indicated that when subgingival bacteria were evaluated together, P. micros and C. rectus may have a role in increasing the risk for PLBW, although no single bacteria exhibited any relation with the risk of PLBW. Further studies are required to better clarify the possible relationship between periodontal diseases and PLBW.
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| 6. |
- Dahlén, Gunnar, 1944, et al.
(författare)
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A new checkerboard panel for testing bacterial markers in periodontal disease.
- 2006
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Ingår i: Oral microbiology and immunology. - 0902-0055. ; 21:1, s. 6-11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIMS: Various microbiological methods have been used for testing bacterial markers for periodontitis and periodontal disease progression. Most studies have used only a limited number of well recognized bacterial species. The purpose of the present study was to evaluate the association of 13 more recently identified bacterial species in a new panel in comparison with 12 previously more recognized periodontotopathogens ('old panel') using the 'checkerboard' DNA-DNA hybridization method. METHODS: Fifty individuals were chosen who showed at least one site with a probing pocket depth of 6 mm or more (disease) and bleeding on probing and at least one site with a probing pocket depth of 3 mm and without bleeding on probing (health). One diseased and one healthy site on each individual were sampled with the paperpoint technique and the samples were processed in the checkerboard technique against deoxigenin-labeled whole genomic probes to 25 subgingival species representing 12 well recognized and 13 newly identified periodontitis associated species. RESULTS: Twenty-four (out of 25) species were detected more frequently in the subgingival plaque of diseased than healthy sites both at score 1 (> 10(4)) and score 3 (> 10(5)). A significant difference at the higher score (score 3) was noticed for all species of the old panel except for three (Streptococcus intermedius, Selenomonas noxia, and Eikenella corrodens). Of the species in the new panel only Prevotella tannerae, Filifactor alocis, and Porphyromonas endodontalis showed a statistical significant difference between diseased and healthy sites. CONCLUSION: It was concluded that P. tannerae, F. alocis, and P. endodontalis should be added to the 12 species used for routine diagnostics of periodontitis-associated bacterial flora.
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| 7. |
- Dahlén, Gunnar, 1944, et al.
(författare)
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A retrospective study on the microbiology in patients with oral complaints and oral mucosal lesions.
- 2009
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Ingår i: Oral diseases. - : Wiley. - 1601-0825 .- 1354-523X. ; 15:4, s. 265-72
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to microbiologically analyze oral mucosal samples collected during 2 years from patients with oral mucosal complaints. MATERIALS AND METHODS: Mucosal scraping samples were taken from 297 patients and semiquantified by culture for detection of opportunistic microorganisms e.g. Staphylococcus aureus, enterococci, aerobic Gram-negative bacilli (AGNB) and yeasts. Antibiotic susceptibility test was performed. RESULTS: Altogether 297 patients were sampled (mean age 56.8 +/- 20.7). Among the 110 patients with known medical condition, 48 were systemically immunocompromised, 35 had systemic diseases, and 27 had only local oral complaints. Opportunists in moderate growth or more were present commonly in all three groups and most frequent in the immunocompromised patients (66.7%). Candida species were the most frequent opportunist (68.8%), however, their level was low and combinations with bacterial opportunists were common (39.6%). All bacterial opportunists tested were antibiotic multiresistant. Follow-up samples were collected in 23 cases out of which seven showed still presence of opportunists in heavy growth despite repeated treatment with ciprofloxacin. CONCLUSIONS: This study showed a frequent presence of bacterial and fungal opportunists in patients with oral mucosal complaints, which were most common in immunocompromised individuals, however, also frequent in patients with local oral complaints only. Systematic evaluation of different treatment strategies is needed.
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| 8. |
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| 9. |
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| 10. |
- Dahlén, Gunnar, 1944
(författare)
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Microbiological diagnostics in oral diseases.
- 2006
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Ingår i: Acta odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 64:3, s. 164-8
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Tidskriftsartikel (refereegranskat)abstract
- Most infections of the oral cavity, including the major dental diseases caries and periodontitis, are opportunistic in nature. They are caused or maintained by microorganisms of the resident or transient flora normally present in low numbers and not pathogenic, but in certain circumstances develop infections. Mucosal infections have some degree of specificity [e.g. Candida spp., Staphylococcus aureus, and enterics] and a microbiological test can be interpreted accurately for clinical diagnosis and choice of treatment. Subepithelial or deep infections, however, include a number of species from the resident flora, mainly anaerobes whose role in the infections is difficult to interpret. However, microbiological tests and the presence of certain bacterial species could be used for treatment control, risk-evaluation and even for patient motivation in the prevention of these diseases. Microbiological diagnosis can be used in general practice for several purposes and in various situations that can be of great value for the dental patient.
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