Number Of Mutans Streptococci Research Articles

Caries-Preventive Effect of Dentifrices Containing Various Types and Concentrations of Fluorides and Sugar Alcohols

The caries-inhibiting effect of unsupervised daily use of four different toothpastes was compared in a 3-year clinical and microbiological study: (1) 0.8% sodium monofluorophosphate (MFP) with 3% xylitol and 6% sorbitol; (2) 0.03% sodium fluoride with 3% xylitol and 6% sorbitol; (3) 0.8% MFP with 9% sorbitol, and (4) 0.03% sodium fluoride with 9% sorbitol. In all 284 children, 12-13 years old at baseline, took part in the study. After 3 years, no statistically significant differences were found between the different toothpaste groups concerning either development of initial or gross caries lesions or number of mutans streptococci and lactobacilli in saliva. However, children with no detectable approximal caries at baseline, who used the MFP toothpaste with the xylitol-sorbitol mixture, showed a lower (p less than 0.05) caries increment as compared with children who used the MFP toothpaste with sorbitol alone.

Mutans streptococci in saliva and dental caries in children living in a high and a low fluoride area

The aim of this study was to obtain information about the quantitative distribution of salivary mutans streptococci and the relation to dental caries in children with contrasting levels of natural water fluoride. A total of 698 schoolchildren aged 12 yr were selected from areas with high (1.2 ppm) or low (0.1 ppm) fluoride concentration in the drinking water. They were all examined for the presence and number of mutans streptococci in saliva by a specially prepared plastic strip, the "Strip mutans" method, cultivated in a selective broth. Data on the caries experience were obtained from the dental records and from bite-wing radiographs. Mutans streptococci were identified in 82% of all children with no difference between the two areas. The number of mutans streptococci was however significantly (p less than 0.05) lower among the children from the high fluoride area than those from the low fluoride area. Children with no detectable or low levels (0-10 CFU) of mutans streptococci had less caries experience than children with moderate or high levels (11- greater than 500 CFU) in both areas investigated.

Salivary conditions and cariogenic microorganisms in 55, 65, and 75‐year‐old Swedish individuals

Secretion rate, buffer capacity, and cariogenic microorganisms of resting and stimulated whole saliva were examined in 208 55-, 65-, and 75-yr-old Swedes. The secretion rate for both resting and stimulated saliva decreased with age. When the use of drugs was taken into account the difference in terms of age group was significant for resting saliva alone (P less than 0.01). In 22% the resting saliva was less than 0.1 ml/min, and in 5% the stimulated saliva was less than 0.7 ml/min. Persons with subjective dryness in the mouth had a lower salivary flow. Men had higher secretion rates than women irrespective of medication (P less than 0.05). The buffer capacity was strongly correlated to the secretion rate of both resting and stimulated saliva (r = 0.39 and r = 0.44, respectively). The number of mutans streptococci and lactobacilli increased with age, although significant in terms of age group for lactobacilli alone (P less than 0.05). The number of these microorganisms was lower in resting saliva than in stimulated saliva (P less than 0.0001). Individuals harboring both Streptococcus mutans and Streptococcus sobrinus had higher values of mutans streptococci in resting and stimulated saliva than those harboring only S. mutans (P less than 0.001). Actinomyces viscosus and Actinomyces naeslundii comprised greater than or equal to 1% of the total CFU in 89% of the plaque samples. The corresponding figures for lactobacilli and mutans streptococci were 6% and 38%, respectively.

Longitudinal study of caries and cariogenic bacteria in an elderly disabled population

A 2-yr longitudinal study was conducted among elderly disabled residents of a longterm care facility. Each of the 50 subjects examined at the beginning of the study had a mean of 14 teeth, with a mean of 6 carious and 6 restored teeth, per person. Most of the subjects had very poor oral hygiene, and 26 of them had dental plaque that produced cultures of mutans streptococci and lactobacilli in excess of 10(5) CFU/ml. At the end of the first year, 40 subjects were examined again and, apart from a decrease in the mean number of carious root lesions per person, there was very little change in their dental or microbial status. Although only 18 subjects were available at the end of the second year, they presented with fewer carious lesions after 2 yr. The reduction in caries appeared to result from the remineralization of tooth structure, but new lesions did appear in 33% of the 1-yr group, and in 78% of the 2-yr group. This dynamic environment around the teeth produced a mean net incidence of one lesion in the first year, and three lesions over 2 yr. There was a significant (P less than 0.05) association between large (greater than 10(5) CFU/ml) numbers of mutans streptococci and the development of new lesions, but there was no association between the dental status of the subjects and the dental treatment they received. Overall, the results indicate that caries is not rampant in this population.

Correlations between Numbers of Microf lora in Plaque and Saliva

An epidemiologic investigation to reliably identify caries-susceptible subjects by microbiological and chemical assessment of plaque and saliva is currently in progress. As part of that study, the numerical relationships of mutans streptococci, lactobacilli and total viable microflora in plaque and saliva among 12- to 15-year-old children in a fluoridated community were determined. Paraffin-stimulated whole saliva and pooled dental plaque were collected. Each sample was suspended in reduced transport fluid, chilled on ice, and assayed. The bivariate normal distribution was found to be a suitable model for the distribution of the pairs [numbers of bacteria in plaque (log10), numbers of bacteria in saliva (log10)]. Statistically significant positive correlations were found between numbers of mutans streptococci in plaque and saliva, and between lactobacilli in plaque and saliva.

Effect of Chlorhexidine Gel Treatment Supplemented with Chlorhexidine Varnish and Resin on Mutans Streptococci and Actinomyces on Root Surfaces

The supplementary effect of chlorhexidine varnish and resin on the reappearance of mutans streptococci and Actinomyces spp. on root surfaces after chlorhexidine gel treatment was studied. In 8 subjects with many restored tooth and exposed root surfaces, highly colonized with mutans streptococci, chlorhexidine varnish and resin were applied to the teeth on one side of the mouth and resin alone to the other side. This treatment significantly prolonged the time period of reduced salivary levels of mutans streptococci when added to a preceding period of chlorhexidine gel treatment. In 3 of the 8 subjects, mutans streptococci were undetected for more than 4 weeks after treatment. There was a significant difference between the chlorhexidine varnish/resin side and the resin side for 5 weeks with regard to the mean numbers of mutans streptococci in root surface plaque, whereas for the Actinomyces spp. no significant differences were found. In 2 subjects harboring both Streptococcus mutans and S. sobrinus, the population of S. sobrinus reappeared more readily in saliva and plaque than S. mutans. The chlorhexidine treatment was less effective in suppressing the population of Actinomyces viscosus/naeslundii than the mutans streptococci.

Prevalence of mutans streptococci and lactobacilli in elderly Swedish individuals.

The number of Streptococcus mutans, Streptococcus sobrinus, and lactobacilli in stimulated whole saliva was examined in 149 elderly persons. More than 10(6) CFU/ml of mutans streptococci were found in 57% of the subjects and 85% had more than 10(5) lactobacilli per ml of saliva. There was no difference in the prevalence of mutans streptococci between edentulous and dentate subjects whereas significantly more lactobacilli were detected in denture wearers. S. mutans was most frequent and was found in 72% of the subjects. S. sobrinus, which was carried by 44% of the persons, was found proportionally in more subjects with dentures than in dentate individuals. In most persons with S. sobrinus, S. mutans was also present but in 8% of the subjects only S. sobrinus was detected. The subjects with both S. mutans and S. sobrinus had higher salivary levels of mutans streptococci than individuals with only S. mutans or S. sobrinus.

Effects of partial sugar restriction for 6 weeks on numbers of Streptococcus mutans in saliva and interdental plaque in man.

Twenty 17-year-old schoolchildren were selected for the study because of high salivary counts of <i>Streptococcus mutans</i> ( > 10⁶ CFU/ml) and a frequent intake of sugars between meals. After a baseline determination of the numbers of <i>S. mutans</i> and lactobacilli in saliva, and of <i>S. mutans</i> in interdental plaque, the subjects were asked to avoid sugar-containing between-meal products, e. g. sweets, chewing gum, soft drinks and confectionery, and to eat a maximum of 4–5 meals/day. After 6 weeks of sugar restriction, the participants were allowed to return to their former food habits and were then followed for a further 6-week period. Seven subjects, also with high salivary counts of <i>S. mutans</i> and a frequent sugar consumption, served as control group. The results showed a statistically significant decrease of mean salivary <i>S. mutans</i> counts from 1.5 × 10⁶ to 0.3 × 10⁶ CFU/ml (p < 0.001) during the sugar restriction period. The mean number of lactobacilli in saliva decreased from 2.3 × 10⁴ to 0.2 × 10⁴ CFU/ml (p < 0.001). Regarding the interdental plaque samples, the number of tooth surfaces with detectable <i>S. mutans</i> were reduced from 52 to 32% (p < 0.001). When the subjects returned to their former food habits, the <i>S. mutans</i> and lactobacillus values almost reached the baseline level again. No obvious changes were found in the control group for any of the studied variables. To conclude, the 6-week period with sugar restriction reduced the number of <i>S. mutans</i> both in saliva and in interproximal spaces. Also the lactobacillus counts in saliva decreased.

Effects of highly concentrated stannous fluoride and chlorhexidine regimes on human dental plaque flora.

The aim of this study was to determine the effect of an intensive antimicrobial treatment on the number of Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus/Actinomyces naeslundii, and the total Colony-forming Units (CFU) in plaque. The dentition of human volunteers was treated in a dental office with either chlorhexidine (5%) or stannous fluoride (8%). Following the office treatment with chlorhexidine, selected volunteers rinsed daily at home for seven or 49 days with chlorhexidine solution (0.2%), while another group flossed daily at home for seven days with dental floss impregnated with chlorhexidine. On days one, seven, 21, 35, and 49 after the local applications, we took saliva samples and plaque samples from fissures, smooth surfaces, and approximal areas. Chlorhexidine and stannous fluoride suppressed S. mutans and the Actinomyces species on all surfaces and in saliva. S. mutans on tooth surfaces was suppressed for approximately seven days and returned to the baseline level at day 21. A. viscosus/naeslundii was suppressed for more than seven days on the teeth. S. sanguis and the total CFU returned to the baseline level within seven days on all surfaces and in saliva. Rinsing or flossing with chlorhexidine suppressed S. mutans during the period of time that these supplements were used. Brushing for seven days with chlorhexidine gel (1%) without a preceding intensive chlorhexidine treatment had virtually no effect on S. mutans in approximal areas and in saliva, but suppressed S. mutans in fissures and on smooth surfaces.

Oral condition of patients with leukemia and severe aplastic anemia: Follow-up 1 year after bone marrow transplantation

Twenty patients with leukemia and seven patients with severe aplastic anemia who had been treated with bone marrow transplantation were investigated 1 year after transplantation to assess their oral condition. Ten patients had mild clinical chronic graft-versus-host disease (GVHD), and three patients had moderate or severe GVHD. Histopathologic changes in the oral mucosa or the minor salivary glands were observed in nineteen patients. Clinical changes in the oral mucosa were observed in sixteen of those patients. Colonization with Candida albicans was more frequent in patients with advanced histopathologic changes in oral mucosa. The numbers of Streptococcus mutans and lactobacilli and the whole salivary flow rate were not correlated to high or low caries incidence. Whole salivary flow rate were not correlated to GVHD but rather, to conditioning with total body irradiation (p <0.05).

Effects of Dietary Carbohydrates on the Numbers of Streptococcus mutans and Actinomyces viscosus in Dental Plaque of Mono-infected Gnotobiotic Rats

Dietary sucrose and glucose are known to promote the accumulation of, respectively, Streptococcus mutans and Actinomyces viscosus in complex dental plaque microflora. In this study, we have investigated the effects of these carbohydrates on the numbers of S. mutans and A. viscosus colonizing the teeth of mono-infected gnotobiotic rats. Sucrose at a dietary concentration of between 0.25 and 0.5 percent (corresponding with 7-15 mM in the drinking water) caused an increase in the numbers of S. mutans. This result strongly suggested that the increase was due to extracellular polysaccharide (EPS) synthesis by glucosyltransferase, whose Km value (1.0-7.0 mM) is in the same concentration range. The numbers of A. viscosus increased three-fold when 10% glucose was added to the basal diet. It seems plausible that this was due to extracellular heteropolysaccharide produced by A. viscosus in the presence of excess glucose. Although in most microbial ecosystems provision of additional substrates leads to an increase in biomass, glucose had only a small effect on the numbers of S. mutans. Mechanical dislodging forces could be limiting the accumulation of dental plaque. EPS synthesis from dietary carbohydrates seems to enable the population to withstand mechanical dislodging at least partially by providing a matrix wherein cells are entrapped or to which the cells are firmly attached.

Streptococcus mutans in plaque and saliva after mouthrinsing with SnF2

Mouthrinses with SnF2 in 11 subjects significantly reduced (P less than 0.01) the total colony forming units (CFU) count and the numbers of Streptococcus mutans and Streptococcus sanguis in plaque. The numbers of S. mutans and S. sanguis were significantly more reduced than was the total CFU count. After rinsing with SnF2S. sanguis was present in 97% and S. mutans in only 42% of plaque samples from tooth surfaces where they were detected after rinsing with water. SnF2 also significantly reduced (P less than 0.01) the number of S. mutans in saliva. Mouthrinses with NaF did not markedly affect the number of S. mutans either in plaque or in saliva.

Protein components in saliva and plaque fluid from irradiated primates

Irradiation of the major salivary glands of monkeys (Macaca mulatta) fed cariogenic diets leads to caries clinically indistinguishable from radiation caries in man. This study compares the organic composition of individual samples of plaque fluid and saliva from irradiated and control monkeys receiving the same cariogenic diet. Plaque and saliva were collected from fasting, tranquillised animals. Four irradiated animals were sampled repeatedly as were non-irradiated controls. Total protein, albumin, immunoglobulins A, G, and M, and the third component of complement (C'3) were quantitated in plaque fluid and whole saliva. Salivary amylase and peroxidase activities were also determined. Plaque fluid and saliva samples were also subjected to polyacrylamide gel electrophoresis. The total viable anaerobic count and numbers of Streptococcus mutans were determined in samples of plaque. The results suggest that the major effect of irradiation leading to increased numbers of S. mutans and caries susceptibility is in the amount, and not the composition, of the saliva produced by the residual gland tissue. The scanty flow of saliva may reduce the effectiveness of cleansing, buffering and lubrication mechanisms as well as resulting in a marked reduction in the total amount of specific and non-specific immune factors entering the mouth.

Effect of sucrose rinses on bacterial colonization on amalgam and composite.

The effect of sucrose rinses on the bacteriology of early plaque on enamel, amalgam and composite was investigated. Three test persons rinsed with a 15% sucrose solution every hour for 12 h prior to the insertion of the test materials. Round disks of amalgam and composite were carried on the buccal surfaces of the upper molars for 2 1/2 h. Sucrose rinses were found to have an effect both on plaque composition and on the amount of plaque on composite, but not no enamel or on amalgam. A small increase in the number of Streptococcus mutans as well as a general increase in the number of bacteria were found.

Coupling Sugar&lt;sup&gt;&amp;reg;&lt;/sup&gt;の歯垢沈着に及ぼす影響について

The purpose of this investigation was to evaluate plaque accumulation on tooth surfaces in monkeys comparing sucrose with coupling sugar clinically and microbiologically. This coupling sugar was developed in substitution for sucrose in Japan.At first, clinical observation was performed. Ten monkeys were used and fed coupling sugar and sucrose. Dental deposits was stained by 0.5% basic fuchsin at 2, 4, 7 and 10 days. The standardized photographs of the tooth surfaces were taken by planimetric method. The plaque accumulation rate was analyzed by projecting the color slide on section paper. In the coupling sugar group, the accumulation rate of heavily stained plaque was less than that of the sucrose group. Though, no difference was found in total plaque accumulation rate between both groups.The second, two monkeys were employed for analyzing plaque microbiologically. The samples of the microbial plaque were taken at 4, 7 and 9 days on the labio-buccal tooth surfaces. Plaque samples were handled carefully and immediately dispersed in Manganiello's media and sonicated. Then, the suspension was dropped onto blood agar plates, MS-agar plates, MS-B agar plates, Actinomyces selective agar plates and Neisseria selective agar plates. The Neisseria selective agar plates were cultured aerobically. The other agar plates were cultured in Gas Pak jar anaerobically. The number of the colonies grown on the agar plates were counted. The number of Streptococcus mutans in coupling sugar group was less than in the sucrose group. There was, however, no difference between the two groups concerning total microorganisms, Streptococcus numbers, Actinomyces numbers and Neisseria numbers. Those results may be due to the action of such components of coupling sugar as maltose, glycosyl sucrose and maltosyl sucrose.