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ABSTRACT: A modified Carlsson-Crittenden cup was used to collect three consecutive 0.5 ml samples of stimulated saliva from the parotid glands of 14 individuals with no known salivary disease and 14 patients with Sjögren's syndrome. Microbiological culture yielded bacteria from 30 of the 42 samples from healthy individuals and all 33 specimens obtained from patients with Sjögren's syndrome. The number and spectrum of bacterial species encountered in the two groups was similar, with a predominance of facultative alpha-haemolytic streptococci. The mean number of isolates (healthy group, 3.4; Sjögren's group, 3.7) and the mean viable concentration (healthy group, 6.9 × 103 c.f.u./ml, Sjögren's group, 4.2 × I03 c.f.u./ml) was greater in the first sample and fell in subsequent samples in both groups. The only significant difference was a significantly greatest (P < 0 05) mean number of isolates in the third 0.5 ml sample from patients with Sjögren's syndrome (2.6) compared to those in the healthy group (1.2). These results indicate that the duct of the parotid gland does have a microbial flora both in health and disease.
07/2009; 6(1):29-34.
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ABSTRACT: Methods currently in use to measure bacterial adherence to exfoliated buccal epithelial cells are unsuitable for small poorly staining bacteria. An epifluorescence technique was developed, therefore, using acridine orange in pH 3·3 citrate/sodium hydroxide buffer which permitted good visualisation of the smallest test bacteria when attached to buccal cells. In addition, a novel method for standardising bacterial suspensions by relating total counts of bacteria deposited on filters to optical density measurements was used. The adherence properties of a total of eighteen fresh and type strains (including bacterial species implicated in the pathogenesis of periodontal disease and species regarded as members of the normal commensal flora) were measured using these methods. Approximately half of the strains tested adhered well to buccal cells, including fresh isolates of Bacteroides gingivalis, Veillonella species, Streptococcus salivarius and Streptococcus sanguis. Adherence did not correlate in all cases with the known distribution of these species in vivo, although the fresh strains correlated more closely and adhered in higher numbers than the type strains.
07/2009; 1(4):221-225.
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ABSTRACT: Whilst the limited usefulness of caries activity tests based solely on counts of mutans streptococci is becoming increasingly apparent, to date, little attention has been paid to potential differences in the virulence of strains isolated from patients with varying disease experience. Recently an in vitro test was described involving the dissolution of bovine enamel, as a means of determining the cariogenic potential of S. mutans strains. The current study aimed to investigate this test further and to compare the dissolution of bovine enamel and different hydroxyapatite preparations as a possible means of differentiating strains of S. mutans with regard to cariogenicity. In the presence of a 5 per cent sucrose solution, six strains were incubated with either bovine enamel, solid hydroxyapatite, or powdered hydroxyapatite for 5, 24 or 48 h, following which acid anion production, calcium release and change in pH were measured. The results showed that incubation with the powdered hydroxyapatite for 5 h resulted in significant differences between strains which correlated with clinical disease experience. It is suggested that this improved assay could be used to investigate further the clinical significance of the relationship between in vitro cariogenic potential and caries experience.
07/2009; 7(3):145-152.
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ABSTRACT: The presence of a capsule was determined for 198 bacterial strains (57 facultative anaerobes, 141 strict anaerobes) isolated from pus samples aspirated from 40 acute dentoalveolar abscesses. A total of 133 (67 per cent) of the isolates (42 facultative anaerobes, 91 strict anaerobes) were found to have a capsule. Possession of a capsule may in part explain the apparent pathogenicity of the bacterial species encountered in acute dentoalveolar abscess.
07/2009; 6(1):11-15.
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ABSTRACT: An appliance model was used in this study to determine the predominant cultivable microflora involved in early dental plaque formation on human enamel surfaces. Twelve enamel slabs were mounted on either side of an intraoral appliance, and the device was worn for periods of 48 h under (1) ‘normal’ conditions, and (2) with extraoral sucrose applications, nine times daily. Plaque samples were removed from the surface of different slabs at various time-periods, and the bacterial composition determined, with the 4036 isolates being expressed both as percentage and absolute counts. Streptococcus species dominated the plaque microflora at all sampling times, with S.oralis and S.sanguis predominating. A significant increase in total bacterial counts per mm2 enamel occurred from 2 to 48 h, and although sucrose had little effect on the percentage counts of organisms, most genera and species were present in significantly higher numbers per mm2 enamel in sites exposed to sucrose. This study demonstrates the importance of expressing results as absolute as well as proportional counts. Furthermore the appliance appears to offer some advantages over previously used models since (1) the use of multiple slabs allows longitudinal studies to be performed and (2) two experimental conditions can be investigated simultaneously, one on each side of the mouth.
07/2009; 4(1):39-46.
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ABSTRACT: The in vitro lysozyme susceptibility of three oral isolates of Candida albicans cultured in carbohydrate-supplemented media was studied. Lysozyme was shown to have a dose- and time-dependent killing effect on C. albicans isolates. Fungieidal activity persisted to varying degrees when yeast isolates were cultured in a variety of carbohydrates (glucose, galascrose. sucrose, maltose. xylitol and laelose) before exposure to 20 μg/ml lysozyme. Sucrose and galactose grown yeasts exhibited increased resistance to iysozyne conipared with (in decreasing order) those grown in glucose, maltose, xylnol or laelose. Further, the C albicans isolates tested demonstrated strain variations in their susceptibility to lysozyme. These results suggesl that dietary carbohydrate may play a role in modulating the yeast cell populations in the oral —– by altering the fungal susceptibility to salivary lysozyme.
Oral Microbiology and Immunology 12/2007; 8(3):177 - 181. · 2.81 Impact Factor
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ABSTRACT: Denture stomatitis (DS) is the commonest form of oral Candida infection. Although it has been suggested that the acidic conditions prevailing beneath maxillary dentures may potentiate palatal inflammation associated with DS, little is known about the pH and carboxylic acids of denture plaque in subjects with and without the disease. Therefore, qualitative and quantitative analyses of short-chain carboxylic acids and pH of maxillary denture plaque of ten patients and nine controls were performed. Gram-stained smears of plaque revealed numerous yeasts in the DS plaque while yeasts were absent in control plaque. Acetate, lactate, propionate, succinate, formate and pyruvate were present in descending order of concentration in all plaque samples. DS plaque was more acidic and contained significantly lower concentrations of lactate ions than control plaque. These results imply that the carboxylic acids produced by the microflora of denture plaque may be aetiologically involved in the pathogenesis of denture stomatitis.
Journal of Oral Pathology and Medicine 04/2006; 12(2):84 - 89. · 1.63 Impact Factor
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ABSTRACT: The aim of this cross-sectional study was to investigate the clinical application of chairside tests for gingival crevicular fluid (GCF) aspartale amino-transferase (AST) levels and plaque BANA hydrolysis activity with the presence of the periodontal pathogens Porphyromonas gingivalis and Actinohacillus action-mycetemcomitans. The study comprised 100 periodontitis sites (pocket depths≥4 mm. GI = 3) from 10 patients with chronic adult periodontitis and 100 control sites (pocket depths <4 mm. GI<3) from 10 periodontally healthy patients comprising 55 healthy sites (pocket depths <4 mm. GI=0) and 45 gingivitis sites (pocket depths <4 mm, GI=1 or 2). The values for both BANA hydrolysis and AST levels were significantly higher in samples from periodontitis compared with gingivitis and healthy sites (p<0.001), A. actinomycetemcomitans was identified in 45% and P. gingivalis in 17% of periodontitis sites but neither pathogen was recovered from control sites and there was no significant correlation with (he clinical parameters measured. There was no significant relationship between the presence of P. gingivalis and/or A. actinmycetemcomitans with BANA hydrolysis or AST levels. A significant correlation (p=0.0017) was observed between BANA hydrolysis and pocket depth and between AST hydrolysis and the GI (p=0.01). This study failed to demonstrate a positive association between chairside analysis of GCF metabolites for AST levels and/or BANA hydrolysis with P. gingivalis and A. actinomycetemcomitans. However, the GCF metabolites had a significant correlation with periodontally diseased sites in patients with chronic adult periodontitis and may help confirm clinical observations.
Journal Of Clinical Periodontology 12/2005; 25(4):334 - 339. · 3.00 Impact Factor
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ABSTRACT: To develop a simple and flexible novel in vitro model system to grow films of oral bacteria that could be used to study aspects of dental caries.
Standardized suspensions of bacteria were inoculated into Ultrafree-CL (Millipore) ultrafiltration units at various densities. These were incubated for varying time intervals with a range of carbon sources. The bacterial films reproducibly achieved between 107 and 108 cfu cm-2, irrespective of the number inoculated and with no significant changes for 14 d. However, Streptococcus mutans grew through membranes with pores of diameter greater than 0.1 microm after 6 d. Culture of films in sucrose or water for 6 d led to a decreased number of colony-forming units, but returning them to broth reversed this.
Reproducible films of oral bacteria can be cultured in Ultrafree-CL units.
This study has shown that Ultrafree-CL units can be used as a simple model system to grow biofilms that could be used for dental caries research.
Journal of Applied Microbiology 08/2001; 91(1):139-46. · 2.34 Impact Factor
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ABSTRACT: Aims: To develop a simple and flexible novel in vitro model system to grow films of oral bacteria that could be used to study aspects of dental caries.Methods and Results: Standardized suspensions of bacteria were inoculated into Ultrafree-CL (Millipore) ultrafiltration units at various densities. These were incubated for varying time intervals with a range of carbon sources. The bacterial films reproducibly achieved between 107 and 108 cfu cm−2, irrespective of the number inoculated and with no significant changes for 14 d. However, Streptococcus mutans grew through membranes with pores of diameter greater than 0·1 μm after 6 d. Culture of films in sucrose or water for 6 d led to a decreased number of colony-forming units, but returning them to broth reversed this.Conclusions: Reproducible films of oral bacteria can be cultured in Ultrafree-CL units.Significance and Impact of the Study: This study has shown that Ultrafree-CL units can be used as a simple model system to grow biofilms that could be used for dental caries research.
Journal of Applied Microbiology 06/2001; 91(1):139 - 146. · 2.34 Impact Factor
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ABSTRACT: A national consortium for dental primary care in Scotland has been formed as a result of integrated planning by groups involved in managing and delivering postgraduate dental education in Scotland. In 1998 a partnership was formed with representatives from the Scottish Council for Postgraduate Medical and Dental Education (SCPMDE) and the three Scottish dental institutions at Dundee, Edinburgh and Glasgow Universities. The principal aim of the Consortium is to promote evidence-based dental care through postgraduate education and research. The activities of the Consortium will provide a broadly based adjunct to current postgraduate provision with partner institutions contributing in different ways. Since its inception the Consortium has focused on two main areas: 'Higher Training' for Primary Care. Scottish Dental Practice Based Research Network.
British dental journal 09/2000; 189(4):222-3. · 0.92 Impact Factor
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ABSTRACT: A national consortium for dental primary care in Scotland has been formed as a result of integrated planning by groups involved in managing and delivering postgraduate dental education in Scotland. In 1998 a partnership was formed with representatives from the Scottish Council for Postgraduate Medical and Dental Education (SCPMDE) and the three Scottish dental institutions at Dundee, Edinburgh and Glasgow Universities. The principal aim of the Consortium is to promote evidence-based dental care through postgraduate education and research. The activities of the Consortium will provide a broadly based adjunct to current postgraduate provision with partner institutions contributing in different ways. Since its inception the Consortium has focused on two main areas:
'Higher Training' for Primary Care.Scottish Dental Practice Based Research Network
British dental journal 08/2000; 189(4):222-223. · 0.92 Impact Factor
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ABSTRACT: The aim of this cross-sectional study was to investigate the clinical application of chairside tests for gingival crevicular fluid (GCF) aspartate aminotransferase (AST) levels and plaque BANA hydrolysis activity with the presence of the periodontal pathogens Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans. The study comprised 100 periodontitis sites (pocket depths > or =4 mm, GI=3) from 10 patients with chronic adult periodontitis and 100 control sites (pocket depths <4 mm, GI<3) from 10 periodontally healthy patients comprising 55 healthy sites (pocket depths <4 mm, GI=0) and 45 gingivitis sites (pocket depths <4 mm, GI=1 or 2). The values for both BANA hydrolysis and AST levels were significantly higher in samples from periodontitis compared with gingivitis and healthy sites (p<0.001). A. actinomycetemcomitans was identified in 45% and P. gingivalis in 17% of periodontitis sites but neither pathogen was recovered from control sites and there was no significant correlation with the clinical parameters measured. There was no significant relationship between the presence of P. gingivalis and/or A. actinomycetemcomitans with BANA hydrolysis or AST levels. A significant correlation (p=0.0017) was observed between BANA hydrolysis and pocket depth and between AST hydrolysis and the GI (p=0.01). This study failed to demonstrate a positive association between chairside analysis of GCF metabolites for AST levels and/or BANA hydrolysis with P. gingivalis and A. actinomycetemcomitans. However, the GCF metabolites had a significant correlation with periodontally diseased sites in patients with chronic adult periodontitis and may help confirm clinical observations.
Journal Of Clinical Periodontology 04/1998; 25(4):334-9. · 3.00 Impact Factor
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ABSTRACT: Buccal epithelial cells (BEC) from 12 patients with diabetes mellitus and 12 age- and sex-matched non-diabetic subjects were tested in vitro for adhesion of Candida albicans following exposure to nystatin both in vitro and in vivo. Adhesion was significantly reduced (P < 0.002) to cells from both the diabetic and non-diabetic subjects after in vitro exposure to nystatin, but the reduction in adhesion was variable (5.0-50.7% in control subjects and 0.5-48.4% in diabetic subjects) and equivalent between the two groups. In vivo exposure to nystatin produced no overall significant reduction in candidal adhesion to cells from either diabetic or control subjects.
Journal of Oral Pathology and Medicine 05/1997; 26(5):233-6. · 1.63 Impact Factor
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ABSTRACT: In this study, the major periodontal pathogens Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were detected in subgingival plaque samples from patients with periodontal disease by polymerase chain reaction (PCR) and conventional culture methods. 170 plaque samples from 43 patients were analysed; A. actinomycetemcomitans and P. gingivalis were each detected in 40 (24%) of samples by PCR, whereas conventional culture methods detected A. actinomycetemcomitans and P. gingivalis in 25 (15%) and 18 (11%) of samples, respectively. The proportion of patients carrying A. actinomycetemcomitans in at least 1 sampled periodontal site was 17/43 (40%) by PCR and 13/43 (30%) by culture; for P. gingivalis this was 12/43 (28%) by PCR and 9/43 (21%) by culture. Only 5 samples, from 3 patients, harboured both A. actinomycetemcomitans and P. gingivalis. It is concluded that PCR is more accurate than conventional culture methods for identification of these periodontal pathogens in subgingival plaque samples and has a higher frequency of detection.
Journal of Periodontal Research 11/1996; 31(7):496-501. · 1.69 Impact Factor
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ABSTRACT: The various components of saliva, namely mixed saliva, parotid saliva, submandibular saliva, crevicular fluid and minor (labial) gland secretions, were collected from 63 known HIV antibody seropositive patients. A commercial test system, Wellcozyme HIV 1+2, and an antibody capture ELISA (GACELISA), were compared for sensitivity against all components. Sensitivity of the GACELISA system was 100% in 123 mixed saliva, 121 parotid saliva and 127 labial fluid samples, and 98% in 99 submandibular samples and 127 crevicular fluid samples. Respective figures for Wellcozyme 1+2 were 92%, 55%, 73%, 66% and 63%. Mixed saliva was most easily, conveniently and effectively collected using a plain Salivette. In 241 Salivette samples examined from the 63 patients, GACELISA proved 100% sensitive, and Wellcozyme 95% sensitive. Another form of Salivette impregnated with citric acid was unsuitable for GACELISA and gave a false negative value of 45%. In 197 samples from the gingival margin taken by a dry swab, GACELISA showed a sensitivity of 98% and Wellcozyme 81%. The most sensitive method for demonstrating anti-HIV antibody in saliva is to collect mixed saliva with the plain Salivette system and assay anti-HIV antibody levels by GACELISA.
Journal of Oral Pathology and Medicine 04/1996; 25(3):104-7. · 1.63 Impact Factor
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ABSTRACT: Bacterial colonisation of oral surfaces by microorganisms may be dependent on their interaction with specific host receptor molecules. Primary oral colonisers are known to remove specific proteins from parotid saliva. The aim of this study was to determine whether these interactions facilitate microbial attachment to a surface and hence identify specific salivary components as putative host receptor molecules. Parotid saliva was resolved by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and then electroblotted onto nitrocellulose membranes. Suspensions of fluorescently labelled microorganisms were incubated with the blots and salivary components with adherent bacteria identified as fluorescent bands under ultraviolet (UV) transillumination. Species of streptococci known to be early colonisers of the clean tooth surface were found to adhere specifically to certain salivary proteins, especially to basic proline-rich proteins (PRPs). Polymorphic variations in these patterns could form the basis of differences in oral microflora, susceptibility to oral infections and consequent disease.
Electrophoresis 02/1996; 17(1):266-70. · 3.30 Impact Factor
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ABSTRACT: The aim of this study was to determine whether the Nd:YAG laser energies of 50 and 80 mJ at 10 pulses per second (pps) were capable of improving the clinical parameters associated with periodontal disease. These energy settings were chosen as previous work indicated that higher values would damage root surfaces and that 80 mJ had an in-vitro bactericidal effect. Eighty periodontally affected sites in teeth scheduled for extraction from 11 patients with adult periodontitis were randomly placed in one of the following four treatment groups: 1. laser treatment at 50 mJ, 10 pps for 3 minutes; 2. laser treatment at 80 mJ, 10 pps for 3 minutes; 3. scaling and 4. untreated control. Probing depth, bleeding on probing (BOP), plaque index, gingival index and gingival crevicular fluid (GCF) volume were measured at baseline and week 6. Baseline subgingival microbiological samples were collected, then repeated immediately after treatment and at week 6 to assess the total anaerobic colony forming units (CFU). Only the scaling group showed a significant reduction in pocket depth and BOP (P < 0.001). The microbial samples taken immediately after scaling and laser at 80 mJ and 10 pps treatments showed a significant reduction in total CFU compared with the baseline (P < 0.01), which was sustained only in the scaling group until week 6. Electron microscopy did not reveal any heat damage on the root surfaces. This study demonstrated that application of Nd:YAG laser pulses of 50 mJ and 80 mJ failed to improve the clinical and microbiological parameters of periodontal disease.
British dental journal 01/1996; 180(2):57-62. · 0.92 Impact Factor
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ABSTRACT: To obtain baseline information on the prevalence of oral problems and disease in institutionalized elderly in a Scottish hospital.
A cross-sectional clinical investigation with complementary microbiological studies as appropriate.
A cohort of 147 elderly in five long-term care wards; collection of demographic data; clinical examination to determine: i) the dental and denture status and associated lesions such as Candida-associated denture stomatitis and angular cheilitis, ii) oral mucosal disease; swabs as appropriate for microbiology.
Dental status, root caries prevalence; denture status and hygiene, and associated disease; oral mucosal health.
Median period of institutionalization of 147 patients was 15 months and 65% were aged 80 years or more; the majority were significantly mentally impaired; 52% wore complete dentures, 9% were partially dentate, 19% possessed partial or incomplete dentures; 20% were neither dentate nor had dentures. Of 80 patients who verbalised their complaints, 35% complained of dry mouth and 45% had denture-related problems, principally discomfort. The commonest oral finding was a coated tongue (56%); angular cheilitis was present in 25%, and Candida-associated denture stomatitis in 19%; none had oral ulcers.
There was considerable unmet dental need with significant oral disease and poor levels of oral and denture hygiene in this target group; both dental and medical professionals should act in concert to deliver curative as well as preventative dental care for the elderly living in institutions to improve their quality of life.
Oral Diseases 10/1995; 1(3):147-51. · 2.49 Impact Factor
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ABSTRACT: The limited usefulness of caries activity tests based solely on counts of mutans streptococci has been recognised increasingly. Such tests do not account for potential differences in cariogenicity of Streptococcus mutans strains harboured by individual patients. Hence, this study describes the evaluation of a simple and inexpensive method involving the dissolution of powdered hydroxyapatite as a means of determining the cariogenic potential of 64 freshly isolated strains of S. mutans from 24 children. Whilst it is apparent that differences between strains isolated from individuals could be demonstrated using this test, the variability observed was such that it was not possible to relate in vitro cariogenicity to actual clinical caries experience.
Caries Research 02/1995; 29(6):455-60. · 2.33 Impact Factor
