Salivary mutans streptococci and dental caries patterns in pre-school children

Abstract Recent studies have suggested that the identification of caries as discrete patterns may be valuable in describing and predicting caries experience on an individual basis. The purpose of this study was to assess the association between levels of salivary mutans streptococci and the prevalence, incidence and distribution of caries patterns in the primary dentition. A cohort of pre-school children (n=146, mean age 3.8 yr) were examined for dental caries and sampled for salivary mutans streptococci (SMS) at baseline and once annually for 2 yr. Children's tooth surfaces were categorized into four patterns: pit/fissure, maxillary anterior, posterior proximal, and buccal/lingual smooth surface. Salivary mutans streptococci were enumerated using a tongue blade technique, and were categorized as low (0 CPU), moderate (1–50 CPU) and high (>50 CPU). At year 2, children with high baseline SMS had the 1) highest prevalence of caries (87%) and the highest dmfs (9.15); 2) highest prevalence of each pattern, and 3) greatest number of patterns. Among children with the pit/fissure pattern, those with high baseline SMS had the greatest pit/fissure dmfs after 2 yr. Results show that baseline SMS levels were associated with both cross-sectional and longitudinal caries experience, numbers of caries patterns, and the prevalence and severity of those patterns.     

Temporal Changes in Dental Caries Levels and Patterns in a Native American Preschool Population

Objectives : The purposes of this study were to assess current dental caries experience and levels of mutans streptococci in Apache children in 1993 and to determine how caries levels and patterns were different from 15 years before. Methods : Four-year-old Head Start children ( n =127) were examined for dental caries and sampled for salivary mutans streptococci in 1993. Dental caries information on 113 4-year-old children from the same location was obtained from a chart audit of the 1978–79 Head Start dental examinations. Results : Neither the caries prevalence (95%) nor the prevalence of caries patterns differed between the 1978–79 and 1993 cohorts. However, the level of treatment received in 1993 was greater than that in 1978–79. Children with nursing caries (64%) had a greater severity of fissure caries and a greater prevalence of posterior proximal caries compared with caries-positive children without nursing caries. The mean dmfs and dmft of the children categorized in the high mutans streptococci range were greater than those of children categorized in the moderate range. Conclusion : The caries prevalence found in these preschool Native Americans is among the highest reported for this age group and does not differ from that found at this location 15 years before. It appears that children with nursing caries in this population are at greater risk for posterior caries patterns.     

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.     

Relationships between socioeconomic backgrounds, caries associated microflora and caries experience in 12-year-olds in Bosnia and Herzegovina in 2004

AIM: To present the prevalence of dental caries in Bosnia and Herzegovina (BH), to estimate the levels of salivary mutans streptococci and lactobacilli and compare them with caries prevalence in 12-years-old children from different socioeconomic backgrounds. STUDY DESIGN AND METHODS: A survey was carried out in 8 cantons of the Federation of BH (FBH) and in Republic Srpska (RS) in 2004. The final sample included 560 12-year-olds. The clinical examinations focused on dental status, expressed as DMFT index, and they were carried out by one examiner, following WHO standard methodologies. Additionally, the study involved 109 12-years old children from Sarajevo, divided in three groups, based on their socioeconomic background. For measuring lactobacillus and mutans streptococci (MS) count in saliva Dentocult LB and Dentocult SM-Strip Mutans were used. Levels of MS and lactobacilli were expressed as a score between 0 and 3, indicating very low to very high levels of SM and lactobacilli. RESULTS: The average DMFT of the 12-year-olds was 4.16+/-2.92. On average, 91% of the 12-year-olds were affected with dental caries. The SiC Index was 7.41+/-3.31. Investigating the relationship between caries associated microflora and caries experience in children of different socioeconomic status showed the following: significant difference in caries prevalence was found in children with different living conditions, where children with high socioeconomic status had better oral health compared to the other two groups. For mutans streptococci, 25.7% of the children had mutans class 0, 24.8% class 1, 34.9% class 2 and 14.6% class 3. The mean DMFT for mutans class 0 was 3.50, for class 1 was 4.30, for class 2 was 5.62 and for class 3 was 6.0. For lactobacilli, 38.5% of the children had lactobacilli class 0, 25.7% class 1, 23.9% class 2 and 11.9% class 3. The mean DMFT for lactobacilli class 0 was 4.3, for class 1 was 4.9, for class 2 was 4.8 and for class 3 was 6.0. No significant differences in the level of mutans streptococci and lactobacilli were found between the groups. CONCLUSION: There is moderate caries prevalence among BH 12-year-olds (DMFT 4.16+/-2.92). Caries experience varies between children with different living condition but no relation between levels of salivary mutans streptococci and lactobacilli and socioeconomic status of children could be found.     

Current understanding of the epidemiology mechanisms,and prevention of dental caries in preschool children

The seriousness and societal costs of dental caries in preschool children are enormous. National data shows that caries is highly prevalent in poor and near poor US preschool children, yet this disease is infrequently treated. The etiology includes elevated colonization levels of mutans streptococci, high frequency sugar consumption, and developmental defects on primary teeth. A necessary first step in preventing dental caries in preschool children is evaluating the child's caries risk factors that include socioeconomic status, previous carious experience, presence of white spot lesions, presence of visible plaque, perceived risk by dental professionals, and microbiologic testing for the presence or quantity of mutans streptococci. Based on this knowledge, different preventive strategies, as well as different intensities of preventive therapies, can be employed. Caries preventive strategies in preschool children include diet modifications to reduce high frequency sugar consumption, supervised tooth brushing with fluoridated dentifrice, systemic fluoride supplements to children living in a nonfluoridated area that are at risk for caries, professional topical fluoride with fluoride varnish, and sealants for primary molars.     

Caries prevalence and salivary mutans streptococci in 0–2-year-old children of Japan

The prevalence of caries and the number and species distribution of salivary mutans streptococci in 356 children (aged 0-2 yr old) in Japan were examined twice at an interval of 1 yr. No mutans streptococci were isolated from the predentate children. The detection rate of mutans streptococci and the prevalence of caries increased with age. Mutans streptococci were isolated from 39.9% of the subjects. The majority of isolates were identified as Streptococcus mutans. The concentration of mutans streptococci correlated with the number of erupted teeth (r = 0.339). In addition, the concentration of mutans streptococci was more closely correlated to the caries prevalence of the next year (r = 0.465) than that of the year when the salivary concentration of mutans streptococci was first evaluated (r = 0.368). The children who had no caries but harbored mutans streptococci in the first year showed significantly higher caries prevalence in the next year than did the children with neither caries nor mutans streptococci. These results indicate that the establishment of mutans streptococci is associated with caries initiation in early childhood.     

Dental caries and caries-associated microorganisms in Uruguayan preschool children

The prevalence of dental caries was studied in 3-5-year-old Uruguayan children (n = 76) living in 2 areas with different socioeconomic and cultural conditions. More children from the low socioeconomic area of Las Acacias had caries (68%) than children from the middle- to high-class neighborhood of Pocitos (19%). They also had poorer oral hygiene and a significantly higher caries prevalence (P < 0.05) than those from Pocitos. The occurrence of mutans streptococci and lactobacilli was determined in whole unstimulated saliva and compared with that in debris collected with a loop from the dorsum of the tongue. Mutans streptococci were detected in 42% of the children with significant correlations between the salivary levels of the microorganism and caries experience. Lactobacilli were recovered less frequently (18%). The detection of mutans streptococci in the tongue-loop samples was significantly correlated with that in whole saliva.     

Dental caries and caries-associated microorganisms in Uruguayan preschool children

The prevalence of dental caries was studied in 3-5-year-old Uruguayan children (n = 76) living in 2 areas with different socioeconomic and cultural conditions. More children from the low socioeconomic area of Las Acacias had caries (68%) than children from the middle- to high-class neighborhood of Pocitos (19%). They also had poorer oral hygiene and a significantly higher caries prevalence (P &lt; 0.05) than those from Pocitos. The occurrence of mutans streptococci and lactobacilli was determined in whole unstimulated saliva and compared with that in debris collected with a loop from the dorsum of the tongue. Mutans streptococci were detected in 42% of the children with significant correlations between the salivary levels of the microorganism and caries experience. Lactobacilli were recovered less frequently (18%). The detection of mutans streptococci in the tongue-loop samples was significantly correlated with that in whole saliva.     

Mutans streptococci oral colonization in 12-30-month-old Brazilian children over a one-year follow-up period

OBJECTIVES: The infection levels of mutans streptococci were investigated during a one-year follow-up in children aged 12 to 30 months attending school nurseries where a sucrose-rich diet was provided. METHODS: Oral levels of mutans streptococci obtained from 101 children at baseline and after a one-year follow-up were compared by age, number of teeth, feeding habits, and presence of visible plaque at baseline. Baseline predictors and changes in mutans streptococci levels during the study were compared to caries incidence after one year. RESULTS: Fluctuations in mutans streptococci levels during the follow-up period were not related to feeding habits or presence of visible plaque. Mutans streptococci levels increased after one year among children aged 12 to 24 months, while a significantly higher proportion of those aged 25-30 months showed a decrease in mutans streptococci levels during the study. Multiple logistic regression analysis suggested that high levels of mutans streptococci (> or = 100 cfu) at baseline were associated with a higher caries increment, while reduction in mutans streptococci was negatively associated with caries incidence. CONCLUSIONS: Our data suggest that despite early mutans streptococci infection and high exposure to sucrose, mutans streptococci may achieve relatively stable levels after 2 years of age. Heavy colonization by mutans streptococci in an early age was related to an extremely high caries incidence during childhood, while decreasing levels of mutans streptococci can be associated to the decrease in caries activity.     

The relationship between sweetness preference, levels of salivary mutans streptococci and caries experience in Brazilian pre-school children

Aim . To analyse the relationship between preference for sweetness, levels of salivary mutans streptococci and levels of caries in low socio-economic 4–5-year-old Brazilian children.
Design . A cross-sectional survey.
Subjects and methods . 298 children of both sexes, who, in 1998, were regularly attending public nurseries were randomly selected. Caries experience was assessed according to WHO guidelines. Saliva samples were analysed for mutans streptococci using the spatula method. Children's preference for sugar was measured using the 'Sweet Preference Inventory'. Personal interviews with the mothers were conducted.
Results . 255 children completed all aspects of the research, a response rate of 85·6%. 34·9% of them were caries-free. The mean dmf-s was 4·25 (SD 6·16), the decayed component being 3·56 (SD 5·82) and the filled surfaces, 0·69 (SD 1·85). For these pre-school children; male sex ( P < 0·01), single parent ( P < 0·01), habit of eating or drinking items that contained non-milk extrinsic sugar between meal times ( P < 0·05) and high levels of salivary mutans streptococci ( P < 0·001) were significantly associated with higher dmfs scores. There was no statistical relationship between sweetness preference and dental caries and with mutans streptococci levels.
Conclusion . Levels of salivary mutans streptococci but not sweetness preference were potential good predictors of caries experience among 4–5 years-old-children living in urban area of Brazil.     

Salivary microflora and caries experience in 5-year-old children from two ethnic groups

The purposes of the study were threefold: to compare salivary levels of mutans streptococci and Lactobacillus in 140 5-year-old children from two ethnic groups, to correlate caries experience of each group with bacterial counts, and to determine levels of infectivity which could indicate high caries activity in young children. Pakistani-Muslim and white Caucasian children were paired, matched for age, gender and caries experience. There were no significant differences in mutans streptococci or Lactobacillus levels between the two ethnic groups. However, strong correlations were found between caries experience and levels of both mutans streptococci and Lactobacillus in each ethnic group. Furthermore, mutans streptococci and Lactobacillus levels correlated strongly with one another. For detection of high caries activity, the optimum screening levels of bacteria were > 10(5) cfu/ml for mutans streptococci (sensitivity 78% and specificity 86%) and > 10(4) cfu/ml for Lactobacillus (sensitivity 82% and specificity 89%).     

Mutans streptococci, lactobacilli and caries prevalence in 11-and 12-year-old Icelandic children

Since the caries prevalence has not declined in Iceland as it has in other European countries, it was of interest to study the presence of cariogenic bacteria in Icelandic children. The prevalence of salivary mutans streptococci and lactobacilli was examined in 217 11- and 12-yr-old Icelandic children and was related to their caries prevalence. In 2% of the children mutans streptococci were not found whereas 31% and 35% of the 11-yr-olds and 12-yr-olds respectively carried more than 10(6) CFU per ml saliva. Lactobacilli were not detected in 8% of the children whereas 28% of the 11-yr-olds and 23% of the 12-yr-olds had more than 10(5) CFU per ml saliva. The mean caries prevalence (DFS), initial caries included, for 11-yr-olds was 21.6 and for 12-yr-olds 28.8. Both mutans streptococci and lactobacilli were significantly correlated to each other as well as to caries prevalence. An increased number of these microorganisms, especially the mutans streptococci, were associated with an increased DFS. Children with high salivary counts of mutans streptococci and lactobacilli showed four times higher DFS than children with low numbers. The magnitude of salivary cariogenic bacteria as well as caries prevalence was found to resemble the situation in Sweden 10 yr ago. S. mutans (serotype c/e/f) was carried by all mutans streptococci positive children. S. sobrinus (serotype d/g) was found in 60 children (30.2%). Children with both S. mutans and S. sobrinus had significantly higher salivary counts of mutans streptococci and lactobacilli as well as caries prevalence than children with only S. mutans.     

Dental caries in preschool Beijing and Connecticut children as described by a new caries analysis system

Abstract – A total of 625 children, 3-4 yr old, 426 from Connecticut Head Start programs and 199 from Beijing area nursery schools, were clinically examined for dental caries. Results were analyzed using the traditional dmfs index as well as a new "Caries Analysis System". This new system differentiated between caries patterns and examined the percentage of affected children (Prevalence), the degree to which these children were affected (Severity) and the proportion of total caries each disease pattern represented (Distribution). The Caries Analysis System revealed differences in caries experience and patterns among the racial/ethnic groups that the dmfs index did not. The Beijing children experienced the greatest Prevalence of all caries patterns; however, the Severity and Distribution of the caries patterns were similar to those of the Connecticut children. Within the group of Connecticut children, White children had the lowest Prevalence but the greatest Severity when compared with the Black and Hispanic children.     

Effect of mixed mutans streptococci colonization on caries development

OBJECTIVE: To evaluate the clinical importance of mixed mutans streptococci colonization in predicting caries in preschool children. METHODS: Caries prevalence was examined twice, with a 6-month interval, in 410 preschool children aged 3-4 years at baseline. A commercial strip method was used to evaluate the mutans streptococci score in plaque collected from eight selected interdental spaces and in saliva. Mutans streptococci typing polymerase chain reaction (PCR) assays (Streptococcus sobrinus and Streptococcus mutans, including serotypes c, e, and f) were performed using colonies on the strips as template. RESULTS: Twenty variables were examined in a univariate analysis to predict caries development: questionnaire variables, results of clinical examination, mutans streptococci scores, and PCR detection of S. sobrinus and S. mutans (including serotypes c, e, and f). Sixteen variables showed statistically significant associations (P < 0.04) in the univariate analysis. However, when entered into a logistic regression, only five variables remained significant (P < 0.05): caries experience at baseline; mixed colonization of S. sobrinus and S. mutans including S. mutans serotypes; high plaque mutans streptococci score; habitual use of sweet drinks; and nonuse of fluoride toothpaste. CONCLUSION: 'Mixed mutans streptococci colonization' is a novel measure correlated with caries development in their primary dentition.     

Caries risk assessment in Bosnian children using Cariogram computer model

AIM: To examine caries risk using the Cariogram model, interactive PC program for caries risk evaluation in 12-year-old children and to correlate caries risk in children of different socioeconomic backgrounds. MATERIAL AND METHODS: 109, Sarajevo 12-year-olds in three groups based on socioeconomic background. Baseline data on general health condition, diet frequency and use of fluoride were obtained. DMFT and plaque scores were calculated. Saliva analyses included lactobacillus and mutans streptococci levels in saliva, saliva secretion and buffer capacity. Scores were entered into the Cariogram model and risk was calculated for each child. RESULTS: Most 12-year-old children have a medium risk of caries, with a 59.4% chance of avoiding future caries. In an average caries risk profile of children from Sarajevo the dominant sector is diet, with 12.5% risk; bacteria sector (plaque and mutans streptococci level) 10.8% risk; susceptibility (fluoride, saliva secretion and buffering capacity) 9.7% risk; circumstances (caries experience and medical history) 7.4% risk. Caries risk profiles showed that there are differences in the socioeconomic status of children with significantly greater risk in children with poor living conditions who also have the most unfavourable caries risk profiles. CONCLUSIONS: The Cariogram model can successfully determine caries risk profiles for 12-year-old children of different socioeconomic status and can be used in developing preventive strategies for reducing caries risk in children.     

Effects of a chlorhexidine-fluoride-strontium rinsing program on caries, gingivitis and some salivary bacteria among Finnish school children

Abstract – In order to find out if it is possible to prevent caries and gingivitis by periodical use of chlorhexidine-fluoride mouthrinses with or without strontium, and to find out what effects they have on salivary mutans streptococci and lactobacilli counts, a total of 243 schoolchildren aged 11 yr with high DMFS scores were randomly divided into four groups. One group (C) served as a basic control. Subjects in the second group (GXF) rinsed their mouths twice a day every third week with a rinsing solution containing 0.05% chlorhexidine gluconate and 0.04% NaF. In the third group (CXFS) the rinsing solution contained 500 ppm Sr during the first and second year and 15 ppm during the last 6 months, in addition to chlorhexidine and fluoride. In the fourth group (CX) the solution contained only 0.05% chlorhexidine gluconate. All the rinsing solutions had pH 5.8 buffered with succinic acid-NaOH buffer. After 2 yr and 9 months, the mean DMFS (SD) increments in the C, GXF, GXFS, and GX groups were 3.8 (5.7), 2.5 (3.2), 3.5 (4.8), and 3.4 (5.5), respectively. The percentage of subjects with bleeding gingival units had decreased from initial to final values as follows: C, 81–38; GXF, 88–42; GXFS, 89–56; GX, 89–37. The number of lactobacilli and mutans streptococci in saliva remained virtually unchanged throughout the study. For caries increment and gingival bleeding, the differences between groups were not statistically significant. The chlorhexidine-fluoride combination tended to prevent caries, but the effect on gingival bleeding and salivary counts of mutans streptococci and lactobacilli was negligible.     

Longitudinal study of caries,cariogenic bacteria and diet in children just before and after starting school

Fifty 5-yr-old preschool children living in Akranes, a small community in West Iceland known to have a high caries prevalence, were investigated with respect to caries, salivary counts of mutans streptococci and lactobacilli and consumption of cariogenic foods. Fifteen months later, after being in school for half a year, 43 of the 50 children were reexamined and investigated as before. Mean dmfs scores rose from 7.1 to 9.0. but the scores including initial caries rose from 9.7 to 15.3. Mutans streptococci were carried by 84% of children on both occasions with a mean count 2.1 and 3.6 × 10⁵ cfu/ml. Lactobacillus carriage increased from 29 to 38% and the mean count from 5.1 to 13 × 10³ cfu/ml at 6 yr. The frequency of consumption of sugar-containing foods increased from 4.2 to 5.2 intakes per day and between-meal snacks rose from 3.0 to 3.7 per day. Children classified as “misusing” sugar were 59% at 5 yr and 83% at 6 yr. The mean caries score at 6 yr for children “misusing” sugar was 10.7 but only 2.0 for those not misusing sugar. Thus the deterioration in dental health appears, in these children, to be associated with the increased consumption of sweets and other cariogenic between-meal snacks after starting school.     

Mutans streptococci, lactobacilli and caries experience in 12-year-old Icelandic urban children, 1984 and 1991

Abstract In order to evaluate changes in salivary counts of cariogenic bacteria and relate these to trends in caries experience, stimulated saliva was collected from a 20% random sample of 12-yr-old residents of Reykjavik. Iceland (252 children) in 1991 under conditions consistent with those of a survey conducted in 1984. The mean and median counts of salivary mutans streptococci and lactobacilli remained similar in the two studies. However, the frequency distribution at lower levels of mutans streptococci differed significantly between 1991 and 1984, e.g. in the present study 25.8% of the children had < 10⁵ compared with 13.8% in the study 1984. The mean caries prevalence in the permanent dentition (DFS_tot) was 11.0, which is significantly lower than in 1984 (mean DFS_tot 28.8). A significant difference in caries prevalence was found at various levels of salivary mutans streptococci. Strep. mutans (serotype c/e/f) was carried by all mutans streptococci-positive children, save one child, who carried only Strep. sobrinus. The proportion of 12-yr-olds who carried Strep, sobrinus had decreased significantly to 15.7% from 34.0% in 1984. Significantly more children with Strep. sobrinus showed high levels of total mutans streptococci than children with only Strep. mutans. As the case was in 1984 significantly more Strep. sobrinus carriers had a high level of salivary lactobacilli as well as higher caries prevalence than the children who did not carry this species.     

Decreasing caries prevalence in Japanese preschool children is accompanied with a reduction in mutans streptococci infection

OBJECTIVE: To evaluate the association between decreasing caries prevalence in Japanese preschool children and mutans streptococci (MS) infection. METHODS: The prevalence of caries and salivary MS was examined in 1- to 3-year-old preschool children in 1995 (n = 135) and 2000 (n = 118). RESULTS: The caries prevalence for 3-year-old subjects significantly declined from 65.1% to 37.5% (p < 0.01), reflecting the data seen in Japanese national oral health surveys in 1993 and 1999. Salivary MS detection for 3-year-old subjects significantly declined from 68.3% to 37.5% (p < 0.05). On the other hand, the decrease in the prevalence of caries and salivary MS was not significant in 1- and 2-year-olds. The correlation between caries experience (dft) and the salivary MS score for 3-year-old subjects with low caries prevalence in the later examination (r(s) = 0.479, p < 0.001) was comparable with that in 1995 (r(s) = 0.462, p = 0.001). CONCLUSIONS: The recent decrease in decay in Japan is accompanied with a reduction in MS infection in the deciduous dentition. MS levels are closely related to caries prevalence in preschool children regardless of the extent of caries.     

Prediction of caries in pre-school children in relation to fluoride exposure

The levels of salivary mutans streptococci and caries experience were used as predictors for caries incidence in 3 groups of pre-school children from areas with different levels of natural and topical fluoride exposure. Altogether 1022 children, 4-5 years of age at baseline, were examined according to the WHO-criteria and followed for 2 years. The low fluoride group ( n =374) had a low fluoride level in the piped water and no topical fluoride applications: the F-varnish group ( n =442) had low water fluoride but semiannual topical applications of a fluoride varnish; the optimal fluoride group ( n =206) had an optimal level of fluoride in the drinking water and semiannual F-varnish applications. The number of salivary mutans streptococci was estimated and scored at baseline with the Strip mutans chair-side method. The sampling procedure was repeated in 337 children of the low fluoride group 3 weeks after baseline. In comparison with the low fluoride group, caries incidence was 30% and 60% lower in the F-varnish and the optimal fluoride group respectively. The caries predictive ability decreased with increasing fluoride exposure. The sum of sensitivity and specificity decreased from 151% (65%+86%) in the low fluoride group to 131% (40%+91%) in the optimal fluoride group. The positive predictive value was highest (62%) in the low fluoride group. Repeated salivary samplings at baseline did not improve the caries predictive power. The results suggest that the overall fluoride exposure should be taken into account when caries risk assessment strategies for preschool children are developed and implemented.