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Biomedical subjects

B Krasse

Publications and source records attributed to B Krasse.

At least 37 records · Page 2Linked to original sources

Dental caries and salivary and microbial conditions in 50-60-year-old persons.

In a group of 124 persons, 50-60 yr old, the prevalence at baseline of mutans streptococci (MS) and lactobacilli and the salivary secretion rate and buffer capacity were examined. The mean secretion rate was 1.58 mL/min with a flow rate below 1 mL/min found in 20% of the persons. A buffer capacity below end pH 5.5 was observed in 64% of the subjects. MS was not detected in 5% of the persons whereas 17% had 10(6) or more MS per ml saliva. Lactobacilli were not found in 10% of the persons while 21% had counts in excess of 10(5) CFU mL. A new examination 5 yr later in 1986 revealed no significant changes in secretion rate and buffer capacity or in the population of lactobacilli, whereas markedly elevated levels of salivary MS were found. S. sobrinus was detected in 35-37% of the persons at the two examinations. Persons with both S. mutans and S. sobrinus had more MS than persons with only S. mutans.

Buffers↗

Human strains of mutans streptococci show different cariogenic potential in the hamster model.

The cariogenic potential of fresh humans strains of Streptococcus mutans and Streptococcus sobrinus was examined in hamsters maintained on a high sucrose diet. The strains 1B 16 (S. mutans) and B13 (S. sobrinus) isolated 20-25 yrs ago served as positive controls. Three series of experiments were run. Some strains were tested once and some strains were tested in all 3 experiments. The animals infected with S. sobrinus strains generally showed lower caries scores than those infected with S. mutans strains. Among the groups infected with the different strains of S. mutans the caries scores varied. In one of the experiments the caries score of the animals infected with one of the Icelandic S. mutans strains was significantly higher than that of the positive control group and the group infected with one of the fresh Swedish isolates. Thus, different strains of mutans streptococci where shown to induce varying caries activity in the hamster model.

Adolescent↗

Mutans streptococci in interproximal plaque from amalgam and glass ionomer restorations.

Interproximal plaque samples were collected from newly made class II conventional conservative amalgam (Dispersalloy) and glass ionomer (Ketac Silver) tunnel restorations in 20 adolescents. The percentage viable count of mutans streptococci in samples from glass ionomer restorations (mean 3.1%, median 0.7%) was significantly lower (p less than 0.05) than in samples from amalgam restorations (mean 5.7%, median 3.1%). This suggests that plaque formed on such restorations might have a lower potential to induce recurrent caries than plaque formed on amalgam restorations.

Adolescent↗

Effect of different carriers preventive measures in children highly infected with mutans streptococci.

The caries preventive effect of topical application of fluoride varnish (Duraphat), ferric-aluminum-fluoride solution (FeAlF) and chlorhexidine gel was compared in 2-yr clinical study. Children with more than 10(6) mutans steptococci per ml saliva were selected and a total of 189 13-yr-old children participated in the study. The children in the fluoride groups were treated every third month with either Duraphat or FeAlF-solution. In the chlorhexidine group children with more than 2.5 x 10(5) mutans streptococci per ml of saliva were treated every third month. The mean number of new decayed and filled tooth surfaces was 3.06 in the chlorhexidine group, 5.88 in the Duraphat group, 5.33 in the FeAlF group, and 6.34 in the control group. Thus supervised antimicrobial treatment can significantly reduce the incidence of dental (caries) in children with high numbers of mutans streptococci.

Adolescent↗

Specific microorganisms and dental caries in children.

During the last decades it has been convincingly demonstrated that mutants streptococci and lactobacilli are of etiologic importance in dental caries. The knowledge has been applied in several clinical studies and the results show that microbiological examinations can be valuable adjuncts in the diagnosis, treatment and prevention of dental caries. Although dental caries has declined considerably, some children still develop high caries activity. It is important that such children are identified and given preventive treatment before they develop rampant decay. In this context pediatricians play an important role and the new microbiological knowledge can be a valuable tool.

Adolescent↗

Effect of preventive measures in 50-60-year-olds with a high risk of dental caries.

Salivary and microbial conditions were examined in 124 50-60-yr-old patients attending a dental clinic of the Public Dental Health Service. They were then randomly divided into a control and a test group. Patients with low salivary secretion rate and buffer capacity and high numbers of mutans streptococci and lactobacilli in the test group received special caries preventive measures during 1 yr. In the control group all patients were given prevention according to routine procedures. The incidence of dental caries between the groups was compared. The risk patients in the control group developed 1.67 new carious lesions as compared to 0.19 in the test group. The difference was statistically significant (P less than 0.05). Also the numbers of mutans streptococci and lactobacilli were significantly lower in the risk patients in the test group after 1 yr compared with baseline values. After the experimental year all patients were treated according to routine procedures. Five years after the start of the study a new examination showed increased caries activity in the risk patients in the test group and the gain which had been made during the experimental year was almost lost.

Chlorhexidine↗

Biological factors as indicators of future caries.

During the last ten years the principal biological factors which have been used as indicators of future caries activity are counts of mutans streptococci and lactobacilli. The evidence that these micro-organisms play a key role in the development of dental caries has now become very strong. Methods for the identification and enumeration of mutans streptococci and lactobacilli in saliva and plaque material have been developed which are both feasible and reliable. In a few studies counts of these micro-organisms together with other factors have been related to caries incidence. The validity of the various tests show a large variation but in some studies the predictive value has been high. The best prediction of future caries activity is obtained by the combination of factors which are important contributors to the pathogenesis of dental caries.

Dental Caries↗

The relationship between IgA antibodies to Streptococcus mutans antigens in human saliva and breast milk and the numbers of indigenous oral Streptococcus mutans.

The influence of indigenous Streptococcus mutans on naturally-occurring levels of IgA antibodies was studied in 42 lactating females. Breast milk, parotid and whole-saliva samples were collected and analysed by the ELISA method for IgA antibodies, reacting with antigens from Strep. mutans. All salivas and breast milk showed IgA antibody activity to five antigenic preparations from Strep. mutans and to a pool of Escherichia coli antigens. No correlation was observed between the IgA antibody level in breast milk and that in saliva. The total IgA in breast milk was, however, considerably higher than in the salivas. In subjects with active caries and subjects with high DMFS scores, there was a tendency toward lower levels of IgA antibodies in whole saliva than in subjects with low caries experience. The levels of specific IgA antibodies in saliva did not reflect the amount of indigenous Strep. mutans present in the mouth at the time of sampling.

Adult↗

Microbial conditions and caries increment 2 years after discontinuation of controlled antimicrobial measures in Swedish teenagers.

The purpose of the present study was to examine the long-term effect of a special caries preventive program in teenagers. Over a 3-yr period directed and controlled antimicrobial treatment using Streptococcus mutans as an indicator organism resulted in a remarkable caries reduction especially in children with greater than 10(6) S. mutans per ml of saliva at the start of the study. Two years after discontinuation of the special preventive program 83 out of 101 subjects, 18-19 yr old, were reexamined. All the children had followed the same basic preventive program in the Dental Health Service. The number of S. mutans and lactobacilli per ml of saliva within and between control and test groups was with few exceptions practically the same as 5 yr earlier. During the posttreatment period the caries activity was similar in the control and test groups and lower than during the experimental years especially in the control group. Subjects with initial S. mutans level of greater than 10(6) CFU per ml of saliva continued to show incremental caries scores higher than those subjects with lower S. mutans levels.

Adolescent↗

Caries status and microbial conditions in children in 1973 and 1984.

In 1973 all 9-12-yr-old children in a county in Sweden were examined with regard to caries prevalence, salivary Streptococcus mutans and lactobacilli. Eleven years later the same parameters were analyzed in 250 randomly selected children of the same age and from the same county. Both the number of cariogenic microorganisms and the caries prevalence were significantly lower in 1984 than in 1973 (P less than 0.001). The lower number of S. mutans and lactobacilli could be due to several factors and is probably one of the reasons for the low caries prevalence in the children in the present study.

Child↗

Proportions of Streptococcus mutans, lactobacilli and Actinomyces spp in root surface plaque.

The incidence of Streptococcus mutans, lactobacilli and Actinomyces was examined in root surface dental plaque from 24 subjects with root surface caries and in 24 subjects with exposed root surfaces as a consequence of periodontitis but without root surface caries. Plaque was collected from the most posterior teeth in each quadrant: in the caries group from carious lesions and in the periodontitis group from buccal root surfaces. There were significantly higher proportions of S. mutans and lactobacilli in dental plaque samples taken from subjects suffering from root surface caries than in samples from subjects without root surface caries. The level of the group A. viscosus/naeslundii in the periodontitis group was higher than that found in the root surface caries group, but the difference was not statistically significant.

Actinomyces↗

Prolonged oral reduction of Streptococcus mutans in humans after chlorhexidine disinfection followed by fluoride treatment.

The effect of oral chlorhexidine gel treatment supplemented with fluoride applications was studied in subjects with high salivary levels of S. mutans. In two experiments short-term treatment with a 1% chlorhexidine gel was followed by applications of either a 1% NaF gel daily for 2 weeks or a 1% NaF gel daily for 6 weeks supplemented twice with topical application of an 8% SnF2 solution. The salivary numbers of S. mutans were lower in the test group than in the placebo group after 6 and 12 weeks in experiments 1 and 2, respectively, and considerably lower than the pretreatment values. The findings show that fluoride applications can be a valuable adjunct to chlorhexidine treatment for combatting S. mutans.

Adolescent↗