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(1/1744) The identification of agreed criteria for referral following the dental inspection of children in the school setting.

AIM: To clarify the function of the school based dental inspection. OBJECTIVE: For representatives of the Community Dental Service, General Dental Service and Hospital Dental Service to identify an agreed set of criteria for the referral of children following school dental inspection. DESIGN: Qualitative research methodology used to establish a consensus for the inclusion of referral criteria following dental screening. SETTING: Ellesmere Port, Cheshire, England. MATERIALS: A Delphi technique was used to establish a consensus amongst the study participants on the inclusion of nine possible criteria for referral following dental screening. All participants scored each criterion in the range 1-9, with a score of 1 indicating that referral of individuals with the condition should definitely not take place, and a score of 9 indicating referral should definitely take place. Referral criteria were accepted only if they achieved a group median score of 7 or more, with an interquartile range of three scale points, with the lower value being no less than 7. RESULTS: Four of the nine possible criteria met the agreed group standard for inclusion: 'Sepsis', 'Caries in the secondary dentition', 'Overjet > 10 mm', and 'Registered & caries in the permanent dentition'. CONCLUSION: It is possible to agree clear criteria for the referral of children following the school dental inspection.  (+info)

(2/1744) Purification and properties of bacteriolytic enzymes from Bacillus licheniformis YS-1005 against Streptococcus mutans.

To find a novel lytic enzyme against cariogenic Streptococci, strains showing strong lytic activity have been screened from soil using Streptococcus mutans. A strain identified as Bacillus licheniformis secreted two kinds of lytic enzymes, which were purified by methanol precipitation, CM-cellulose chromatography, gel filtration, and hydroxyapatite chromatography. The molecular weights of these two enzymes, L27 and L45, were 27,000 and 45,000, respectively. Optimum pH and temperature of both enzymes for lytic activity were pH 8 and 37 degrees C. L27 and L45 digest the peptide linkage between L-Ala and D-Glu in peptidoglycan of Streptococcus mutans. The lytic activity was highly specific for Streptococcus mutans, suggesting their potential use as a dental care product.  (+info)

(3/1744) Regulated expression of the Streptococcus mutans dlt genes correlates with intracellular polysaccharide accumulation.

Intracellular polysaccharides (IPS) are glycogen-like storage polymers which contribute significantly to Streptococcus mutans-induced cariogenesis. We previously identified and cloned a locus from the S. mutans chromosome which is required for the accumulation of IPS. Sequencing of this locus revealed at least four contiguous open reading frames, all of which are preceded by a common promoter region and are transcribed in the same direction. Analysis of the amino acid sequence deduced from the first of these open reading frames (ORF1) revealed domains which are highly conserved among D-alanine-activating enzymes (DltA) in Lactobacillus rhamnosus (formerly Lactobacillus casei) and Bacillus subtilis. The deduced amino acid sequences derived from ORF2, -3, and -4 also exhibit extensive similarity to DltB, -C, and -D, respectively, in these microorganisms. However, Southern hybridization experiments indicate that this operon maps to a locus on the S. mutans chromosome which is separate from the glgP, glgA, and glgD genes, whose products are known mediators of bacterial IPS accumulation. We therefore assigned a new dlt designation to the locus which we had formerly called glg. We maintain that the dlt genes are involved in S. mutans IPS accumulation, however, since they complement a mutation in trans which otherwise renders S. mutans IPS deficient. In this study, we found that expression of the S. mutans dlt genes is growth phase dependent and is modulated by carbohydrates internalized via the phosphoenolpyruvate phosphotransferase system (PTS). We demonstrated that the S. mutans dlt genes are expressed constitutively when non-PTS sugars are provided as the sole source of carbohydrate. Consistent with a role for the PTS in dlt expression is a similar constitutive expression of the dlt genes in an S. mutans PTS mutant grown in a chemically defined medium supplemented with glucose. In summary, these findings support a novel role for the dlt gene products in S. mutans IPS accumulation and suggest that dlt expression in this oral pathogen is subject to complex mechanisms of control imposed by growth phase, dietary carbohydrate, and other factors present in the plaque environment.  (+info)

(4/1744) Interactions of Streptococcus mutans fimbria-associated surface proteins with salivary components.

Streptococcus mutans has been implicated as the major causative agent of human dental caries. S. mutans binds to saliva-coated tooth surfaces, and previous studies suggested that fimbriae may play a role in the initial bacterial adherence to salivary components. The objectives of this study were to establish the ability of an S. mutans fimbria preparation to bind to saliva-coated surfaces and determine the specific salivary components that facilitate binding with fimbriae. Enzyme-linked immunosorbent assay (ELISA) established that the S. mutans fimbria preparation bound to components of whole saliva. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot techniques were used to separate components of whole saliva and determine fimbria binding. SDS-PAGE separated 15 major protein bands from saliva samples, and Western blot analysis indicated significant binding of the S. mutans fimbria preparation to a 52-kDa salivary protein. The major fimbria-binding salivary protein was isolated by preparative electrophoresis. The ability of the S. mutans fimbria preparation to bind to the purified salivary protein was confirmed by Western blot analysis and ELISA. Incubation of the purified salivary protein with the S. mutans fimbria preparation significantly neutralized binding of the salivary protein-fimbria complex to saliva-coated surfaces. The salivary protein, whole saliva, and commercial amylase reacted similarly with antiamylase antibody in immunoblots. A purified 65-kDa fimbrial protein was demonstrated to bind to both saliva and amylase. These data indicated that the S. mutans fimbria preparation and a purified fimbrial protein bound to whole-saliva-coated surfaces and that amylase is the major salivary component involved in the binding.  (+info)

(5/1744) Intranasal immunization against dental caries with a Streptococcus mutans-enriched fimbrial preparation.

Streptococcus mutans has been identified as the major etiological agent of human dental caries. The first step in the initiation of infection by this pathogenic bacterium is its attachment (i.e., through bacterial surface proteins such as glucosyltransferases, P1, glucan-binding proteins, and fimbriae) to a suitable receptor. It is hypothesized that a mucosal vaccine against a combination of S. mutans surface proteins would protect against dental caries by inducing specific salivary immunoglobulin A (IgA) antibodies which may reduce bacterial pathogenesis and adhesion to the tooth surface by affecting several adhesins simultaneously. Conventional Sprague-Dawley rats, infected with S. mutans at 18 to 20 days of age, were intranasally immunized with a mixture of S. mutans surface proteins, enriched for fimbriae and conjugated with cholera toxin B subunit (CTB) plus free cholera toxin (CT) at 13, 15, 22, 29, and 36 days of age (group A). Control rats were either not immunized (group B) or immunized with adjuvant alone (CTB and CT [group C]). At the termination of the study (when rats were 46 days of age), immunized animals (group A) had significantly (P < 0.05) higher salivary IgA and serum IgG antibody responses to the mixture of surface proteins and to whole bacterial cells than did the other two groups (B and C). No significant differences were found in the average numbers of recovered S. mutans cells among groups. However, statistically fewer smooth-surface enamel lesions (buccal and lingual) were detected in the immunized group than in the two other groups. Therefore, a mixture of S. mutans surface proteins, enriched with fimbria components, appears to be a promising immunogen candidate for a mucosal vaccine against dental caries.  (+info)

(6/1744) Inhibitory effect of a self-derived peptide on glucosyltransferase of Streptococcus mutans. Possible novel anticaries measures.

Glucosyltransferase (GTF) plays an important role in the development of dental caries. We examined the possible presence of self-inhibitory segments within the enzyme molecule for the purpose of developing anticaries measures through GTF inhibition. Twenty-two synthetic peptides derived from various regions presumably responsible for insoluble-glucan synthesis were studied with respect to their effects on catalytic activity. One of them, which is identical in amino acid sequence to residues 1176-1194, significantly and specifically inhibited both sucrose hydrolysis and glucosyl transfer to glucan by GTF-I. Double-reciprocal analysis revealed that the inhibition is noncompetitive. Scramble peptides, composed of the identical amino acids in randomized sequence, had no effect on GTF-I activity. Furthermore, the peptide is tightly bound to the enzyme once complexed, even in the presence of sodium dodecyl sulfate (SDS). Kinetic analysis using an optical evanescent resonant mirror cuvette system demonstrated that the enzyme-peptide interaction was biphasic. These results indicate that the peptide directly interacts with the enzyme with high affinity and inhibits its activity in a sequence-specific manner. This peptide itself could possibly be an effective agent for prevention of dental caries, although its effectiveness may be improved by further modification.  (+info)

(7/1744) The effect of water fluoridation and social inequalities on dental caries in 5-year-old children.

BACKGROUND: Many studies have shown that water fluoridation dramatically reduces dental caries, but the effect that water fluoridation has upon reducing dental health inequalities is less clear. The aim of this study is to describe the effect that water fluoridation has upon the association between material deprivation and dental caries experience in 5-year-old children. METHODS: It is an ecological descriptive study of dental caries experience using previously obtained data from the British Association for the Study of Community Dentistry's biennial surveys of 5-year-old children. This study examined the following data from seven fluoridated districts and seven comparable non-fluoridated districts in England: 1) dental caries experience using the dmft (decayed, missing, filled teeth) index; 2) the Townsend Deprivation Index of the electoral ward in which the child lived; 3) whether fluoride was present at an optimal concentration in the drinking water or not. RESULTS: A statistically significant interaction was observed between material deprivation (measured by the Townsend Deprivation Index) and water fluoridation (P < 0.001). This means that the social class gradient between material deprivation and dental caries experience is much flatter in fluoridated areas. CONCLUSION: Water fluoridation reduces dental caries experience more in materially deprived wards than in affluent wards and the introduction of water fluoridation would substantially reduce inequalities in dental health.  (+info)

(8/1744) Polymicrobial etiology of dental caries.

The present study was carried out to establish the normal bacterial oral flora and the aerobic and anaerobic bacterial flora from deep seated dental caries, and to determine the antimicrobial sensitivity of the clinical isolates so obtained Streptococcus mutans (48%) and Streptococcus sanguis (20%) were the main aerobic isolates whereas Lactobacillus spp. (52%), Veillonella spp. (24%) and Actinomyces spp. (12%) were the major anaerobic isolates. Hundred percent of the samples from dental caries yielded polymicrobial isolates while in two samples from healthy individuals S. mutans was the sole isolate. As the flora changed from healthy tooth to dental caries it changed from one predominated by anaerobic gram-positive cocci to anaerobic gram-positive bacilli. All the anaerobes isolated were sensitive to metronidazole and cefotaxime, whereas all the isolated streptococci were sensitive to penicillin, erythromycin and clindamycin. Incorporation of the antibiotics in baseline restoration, if technically feasible, has been advocated.  (+info)