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.     

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.     

The microflora of the erupting first permanent molar

The relationship between microflora, eruption status and caries status in the first permanent molar of young children was investigated in 177 children aged 6-7 years. A significantly greater proportion of fully erupted teeth were classified as sound and plaque-free compared to partially erupted teeth. Fully erupted teeth yielded greater numbers and proportions of mutans streptococci compared with significantly greater numbers and proportions of Actinomyces israelii in partially erupted teeth. Logistical regression analysis showed significant associations between white spot lesions in partially erupted teeth and increased numbers of Streptococcus oralis, mutans streptococci and Streptococcus salivarius whereas the presence of Actinomyces naeslundii was associated with health. Significantly greater numbers and proportions of S. oralis and S. salivarius were isolated from partially erupted teeth with white spot lesions whereas Streptococcus mutans was isolated in significantly greater numbers and proportions from fully erupted molars with white spots. This study suggests that organisms other than mutans streptococci are associated with caries development in erupting permanent molar teeth.     

A comparative study of Streptococcus mutans and lactobacilli in mothers and children with severe early childhood caries (SECC) versus a caries free group of children and their corresponding mothers

Early childhood caries (ECC) is recognized as an infectious disease. The first step in its development is primary infection by the bacterium S. mutans which has been identified as the primary etiologic factors in dental caries. Lactobacilli were also found to play a role in the progression of the disease. However, the underlying mechanism of immune response to caries is still unclear. The purpose of this study was to assess the level of cariogenic bacteria namely S. mutans and lactobacilli in caries free children, and children with SECC and their corresponding mothers. he study also aims at correlating the children's levels to their mothers. Sixty children and their mothers attending the dental clinic in King Abdulaziz University participated in our study. Their age ranged from 3 - 5 years. The study groups consisted of 30 children with SECC and a control group comprising of 30 caries free children. Children together with their mothers were examined and their caries level was recorded. Stimulated saliva was collected from each participant for bacterial, immunological assessment, and Lactobacilli counts in each sample were determined Children with SECC had higher levels of S. mutans and Lactobacilli than caries free children. The mothers of children with SECC had a statistically higher count of Lactobacilli than caries free children's mothers. However, the difference was not statistically significant with respect to their S. mutans counts. A significant relationship exists among the mother-child pair in the SECC group with respect to S. mutans level in saliva.     

Prediction of caries development for molar fissures with semiquantitative mutans streptococci tests

Risk-specific caries prevention requires validated and simple parameters for a caries risk assessment. The aim of the study was to evaluate the validity of a site-specific chair-side mutans streptococci (MS) test for the prediction of caries incidence in fissures. In 230 6- to 7-yr-old children, occlusal plaque samples of teeth 16 and 36 were cultured with Dentocult SM tests at 37 degrees C for 24 hr. Caries (DMFS), initial caries, sealants, and a plaque index (QHI) were recorded and oral hygiene habits were assessed. Not erupted, carious, filled and sealed teeth were excluded from the analysis (n = 154). After 2 yr, the status of the fissures was re-examined, and a fluoride history was recorded with a questionnaire filled out by the children's parents. Sealed teeth were excluded again (n = 54). With a classification of MS score 0 or 1 as low and MS score 2 or 3 as high caries risk, 92% agreement was reached by two independently working examiners. The MS scores and caries incidence correlated significantly. Seventy-eight % of the caries progression in fissures was prognosed correctly. Sensitivity was 50%, specificity 82%, positive predictive value 29%, and negative predictive value 92%. Children with caries progression tended to have lower fluoride scores. Low MS scores were most likely to be associated with low caries incidence, while high mutans streptococci scores seem to be partially compensated by other parameters.     

Longitudinal study of the presence of mutans streptococci and lactobacilli in relation to dental caries development in 3-24 month old Thai children

OBJECTIVE: To study the acquisition of mutans streptococci (MS) and lactobacilli in relation to dental caries development in 3-24 month old Thai children. METHODS: Salivary samples were collected from 169 children using sterile wooden tongue depressors at the ages of 3, 9, 12, 18 and 24 months. The blades were pressed onto selective media for MS or lactobacilli. After incubation, the colony forming units of MS/lactobacilli were counted. Dental status was recorded from 9 months old using modified WHO criteria. RESULTS: The number of children with caries and number and severity of decayed teeth significantly increased with age. The presence of MS/lactobacilli was detectable at an early age and the cumulative prevalence of MS/lactobacilli increased with age. Children who were colonised early by MS or lactobacilli showed a higher number of decayed teeth than of those who were colonised later. The children with no MS/lactobacilli had significantly fewer decayed teeth and there was a significant correlation between MS/lactobacilli level and tooth decay. CONCLUSIONS: This longitudinal study shows early colonisation of the mouths of Thai children by MS/lactobacilli and where there are persistently high levels of the bacterias increased risk of development of dental caries.     

Genotyping shows different strains of mutans streptococci between father and child and within parental pairs in Swedish families

The purpose of this study was to investigate whether there was an intrafamilial similarity of mutans streptococcal strains in some Swedish families using chromosomal DNA fingerprinting. Plaque samples were obtained from buccal and occlusal surfaces of 25 three-year-old children, their mothers and 18 fathers. The colonization levels of mutans streptococci were estimated with the "Strip mutans" test, and caries experience was scored by decayed, missing and filled teeth or decayed, extracted and filled teeth. Interviews about medical history, diet regimes, breastfeeding and care of the child were performed. In 11 families isolates of mutans streptococci were detected in all three individuals. These isolates were serotyped by immunofluorescent technique and genotyped using the restriction endonuclease Hae III. The results showed that 5 children harbored mutans streptococci genotypes different from their parents. Six children showed genotypes identical to their mothers. None of the children harbored genotypes similar to their fathers, even though two thirds of the fathers had high or very high mutans streptococci levels. No matching of genotypes was observed within the 11 parental pairs. Mothers as primary caregivers with high "Strip mutans" scores were more often observed in the group with identical genotypes within the mother-child pairs, the "matching group", than in the "no-matching group". These data indicate that the fathers and the children had not acquired each others' strains of mutans streptococci nor had the spouses. The results suggest that the children acquired mutans streptococci both from outside and inside the family.     

Detection of Streptococcus mutans and Streptococcus sobrinus in dental plaque samples from Brazilian preschool children by polymerase chain reaction

The purposes of this study were to detect S. mutans and S. sobrinus by polymerase chain reaction (PCR) amplification, and to relate their presence to the incidence of dental caries in 42 Brazilian preschool children. Dental plaque samples were collected from the cervical margin of all erupted teeth of 5-6 years old children with primary dentition, using a sterile explorer. Examination of the dmft (decayed, missing, filled teeth) index, performed following the World Health Organization (WHO) caries diagnostic criteria, showed a 2.71 score. Prevalence of S. mutans and S. sobrinus was respectively, of 85.7% and 14.3%; no dental plaque sample was either positive or negative for both bacterial species. Children harboring either S. mutans or S. sobrinus presented the same caries prevalence. PCR showed good discriminative ability for differentiation between these species, and suggested that it is a technique suitable for epidemiological studies on mutans streptococci.     

Presence of mutans streptococci and Candida spp. in dental plaque/dentine of carious teeth and early childhood caries

This study determined the presence of mutans streptococci and Candida spp. in supragingival dental plaque and infected dentine of caries-free children, with early childhood caries and caries. Pooled samples of dental plaque and infected dentine were collected from 56 children aged 1-5 years, which were divided into 3 groups: early childhood caries (ECC); caries and caries-free. Infected dentine was collected in ECC and caries groups to compare the frequency of these microorganisms in the collected sites. The samples were inoculated in SB20 and SA medium, for mutans streptococci and Candida spp., respectively, and incubated at 37 degrees C for 48 h. Colony growth was verified and the identification was performed by biochemical tests and CHROMagar Candida. Fisher's test or chi-square (chi(2)) were applied (p=0.05). The more prevalent species were S. mutans and Candida albicans in ECC (85.4% and 60.4%, respectively), independently of the sample site. S. mutans only was significantly associated with carious teeth, whether in early childhood caries or not. However, the frequency of C. albicans in ECC was higher when compared to caries and caries-free groups. There is a significant association between the presence of C. albicans and early childhood caries.     

Factors Influencing Early Childhood Caries of Cleft Lip and/or Palate Children Aged 18 to 36 Months in Southern Thailand

Objective: To clarify whether oral health care behavior or oral cleft status influences early childhood caries in southern Thailand cleft children. Design: A comparative cross-sectional study. Patients, Participants: A total of 138 southern Thai children aged 18 to 36 months comprised two groups of 69 participants, one with cleft lip and/or palate and controls with no cleft. Methods: All children were examined for early childhood caries by using the severity (DMFT/tooth) index. A structured interview was conducted among caregivers, and then multiple regression analysis was applied. Results: Children with oral clefts had a larger number of early childhood caries (ECC) and poorer feeding habits than those without. From a structured questionnaire, the caregivers of children with clefts exercised poorer oral health behavior than those of the controls, but the cleft status was not an important factor for caries prevalence when oral health behaviors were controlled. Multivariate analysis showed that sweetened bottled milk consumption, night-time feeding habit, and frequent sugary food consumption were the variables significantly associated with dental caries. Conclusions: Children with oral clefts in southern Thailand had greater caries experience when compared with noncleft subjects. However, cleft status was not significant for ECC, and night-time feeding habit was the most important factor for higher ECC in children with clefts.     

High prevalence of mutans streptococci in a population with extremely low prevalence of dental caries

The quantitative distribution of the mutans streptococci was investigated in populations with very low caries prevalence. Three hundred and seven school children from rural Sudan with an estimated age of 12 years were examined for dental status and salivary mutans streptococci. Forty-two isolates from the salivary cultures were determined to species level by studying the serogroup and biotype. Denial caries in permanent teeth was diagnosed in 12% of the children and the mean DMFT was 0.17 (range 0-6 DMFT). Caries was confined to fissures. Mutans streptococci were found in 96% of the children and high counts were obtained in 45%. Of 42 isolated strains, 37 belonged to Streptococcus mutans , 5 to Streptococcus sobrinus and none to Streptococcus rattus. The observations show that the mutans streptococci can be widespread in human populations with extremely low prevalence of dental caries and consequently that these bacteria may be readily propagated in human populations without association to a caries-promoting life style.     

Rampant early childhood dental decay: an example from Italy

OBJECTIVES: This study sought to estimate the prevalence and related prediction factors for dental caries in 3- to 5-year-old children in Rome, Italy. METHODS: From a sample of 2,025 children, 1,494 (73.8%) were included in the analysis. Children with at least two primary maxillary incisors showing evidence of caries experience were considered affected by rampant early childhood dental decay (RECDD). Behavioral and socioeconomic variables, mutans streptococci counts, diet, and nutritional status were investigated for their association with RECDD using regression analysis. RESULTS: The prevalence of any caries was 27.3 percent, and was 7.6 percent for RECDD. Among all children, mean dft and dt scores per person were 1.1 (SD = 2.4) and 0.9 (SD = 2.3), respectively; among those classified as having RECDD, scores were 6.9 (SD = 4.2) and 6.7 (SD = 4.3), respectively. Children with RECDD had 56 percent of all the decayed teeth in the sample. Low and medium social classes, use of a baby bottle filled with sweetened beverages, high salivary mutans streptococcal levels, and malnutrition were directly associated with RECDD; milk and yogurt consumption and low Plaque Index scores were inversely associated with the condition. CONCLUSIONS: The high prevalence of RECDD suggests that the implementation of preventive programs should be a priority for dental public health. Because of its high prevalence among children as young as 3 years of age, preventive measures targeted toward pregnant women and toddlers should be developed and tested, while kindergarten students could be used for monitoring RECDD prevalence and for detection of communities at risk.     

WHO pathfinder caries survey in Beijing extended with data for prevalence of mutans streptococci.

A pathfinder caries survey was carried out in Beijing, People's Republic of China, using WHO standard methodologies, in order to estimate the trend by comparing the results with the 1981 caries survey, performed in the same area. Simultaneously, the levels of mutans streptococci in the group were estimated in order to define the proportion of children with high and low mutans levels. Twelve-year-old children were randomly selected from schools in five districts within the city limits. Examinations for caries were performed according to 'WHO Oral Health Surveys' by two calibrated examiners. A total of 178 children were examined for caries and 156 of them were randomly selected for saliva sampling of mutans streptococci, using the 'Strip mutans' method. The number of colonies adhering to the strips were compared with a chart, supplied by the manufacturer, and given a score between 0 and 3, indicating low to very high saliva mutans counts, respectively. The results showed a mean DMFT of 1.87 (1.61-0.06-0.20, for decayed, missing and filled teeth respectively); 66.3 per cent of the children were affected. Fourteen per cent had mutans class 0, 28 per cent class 1, 35 per cent class 2 and 23 per cent class 3. The mean DFT, for each mutans class was 0.82, 1.48, 2.09 and 2.69, respectively. The differences were statistically significant (P = 0.0015). In the lowest mutans class, 50 per cent had caries and the mean number of teeth requiring conservative care was 0.68. For the high mutans group, the corresponding values were 72 per cent and 2.11 teeth.(ABSTRACT TRUNCATED AT 250 WORDS)     

奶瓶龋儿童口腔变链菌的研究

目的：研究儿童口腔内的变链菌基因型与奶瓶龋易感性的关系。方法：取20名奶瓶龋及20名无龋儿童牙菌斑及唾液接种于TYCSB培养基计数并筛选MS,采用AP－PCR法鉴定变链菌基因型。结果：奶瓶龋组儿童唾液及菌斑变链菌计数高于无龋组;并且有两种以上基因型变链菌的比例也高于对照组（14／20vs 5/20)。结论：患有奶瓶龋的儿童不仅变链菌计数高,而且多数被两个以上基因型的MS感染。     

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 and lactobacilli in breast-fed children with rampant caries.

This study aimed to investigate the prevalence of selected components of the oral microflora in breast-fed children who developed rampant caries (resembling nursing caries) under hitherto unexplained circumstances. Dental plaque and saliva samples were collected from breast-fed children, aged between 1 and 2.5 years, with and without rampant caries. Mutans streptococci and lactobacilli were isolated from dental plaque of all children with rampant caries and from most caries-free children. None of the colonies of mutans streptococci resembled those of Streptococcus sobrinus. The mean counts of the mutans streptococci and lactobacilli were 100-fold higher in plaque samples from children with rampant caries as compared with caries-free children. No difference could be found between the numbers of mutans streptococci in plaque overlaying cavities and that from adjacent sound enamel. In contrast, the counts of lactobacilli in plaque were approximately 100-fold higher from cavities than from sound surfaces. The levels of mutans streptococci in saliva were directly related to the presence of rampant caries. The results show that caries-free and caries-active breast-fed children, aged 1 to 2.5 years, harbour mutans streptococci and lactobacilli on their teeth. Rampant caries in these children can occur in the absence of nursing bottles or any other feeding abuse during weaning and in the presence of an aciduric plaque microflora, as has been reported for children with nursing bottle caries.     

Immunoglobulin A reaction to oral streptococci in saliva of subjects with different combinations of caries and levels of mutans streptococci

The aim of this study, performed in Bangkok, was to study whether a particular salivary immunoglobulin A (IgA) antibody profile against mutans streptococci could be related to the absence or presence of caries. A group of 12-year-old individuals representing various combinations of mutans streptococci levels and caries experience was selected. Whole saliva stimulated by paraffin-chewing was collected, and the children were investigated for decayed, missing and filled surfaces (DMFS) and teeth (DMFT), following WHO criteria and methods, at baseline and after 2 years. The total amount of salivary IgA was determined by an immunobead enzyme-linked immunosorbent assay, and SDS-PAGE and Western blot analysis was performed using sonicated antigens of Streptococcus mutans and Streptococcus sobrinus strains and, as a control, a Streptococcus parasanguis strain. The results showed that Thai children with low caries prevalence had more distinct immunoblot bands to antigens from mutans streptococci than did the high-caries children. A similar picture was not seen for S. parasanguis. On the whole, the Thai children also showed fewer bands than usual Swedish saliva samples from comparable age groups. The complexity of the relationship between dental caries and IgA in saliva is highlighted.     

Correlation among mutans streptococci counts, dental caries, and IgA to Streptococcus mutans in saliva

Two-hundred and forty individuals were studied, divided into five groups as follows: caries-free children, children with caries, children with rampant caries, young adults with and without caries. Whole stimulated saliva was collected and all individuals were investigated for DMFT/dmft according to the WHO criteria and the simplified oral hygiene index (OHI-S). Quantitative analysis of the total aerobic flora and mutans streptococci in saliva was performed. Also, the level of salivary anti-S. mutans IgA was determined by ELISA. Children with rampant caries showed the highest OHI-S value. The highest total counts of microorganisms were found in the group of children with caries. No statistically significant differences were observed for salivary flow, OHI-S and microorganism counts between the groups of young adults. No correlation between mutans streptococci counts and anti-Streptococcus mutans IgA levels was observed in the studied groups. A correlation between increased anti-Streptococcus mutans IgA levels and caries-free status was observed among young adults but not among children.     

Physicochemical salivary properties, Lactobacillus, mutans streptococci counts and early childhood caries in preschool children of Colombia

Dental caries is a multifactorial disease, in which saliva has an important role. Saliva properties affect the growth of cariogenic microorganisms, so variations below threshold levels are considered risk factors for the development of dental caries. Salivary tests and microbiological counts of cariogenic bacteria are often used for clinical purposes in order to reveal problems that could explain caries development and have been evaluated in multiple studies, but these studies have mainly been carried out on adults. Thus, the aim of this study was to identify physicochemical salivary properties, mutans streptococci and Lactobacillus counts among preschool children, and their relationship with ECC in a cross-sectional study in Medellín, Colombia. Caries was determined using ICDAS criteria for a sample of 201 preschool children. Stimulated saliva samples were processed for bacterial detection, mean flow rate, pH and buffer capacity calculation. Risk variables for ECC were assessed individually and adjusted using a binary logistic regression model. The results showed that 71.14% of study subjects had ECC. Flow rate, final pH and Buffer capacity increased with age, but none of them were related to the presence of ECC. Although OR analysis detected correlations between ECC, gender age, dental eruption stage and Lactobacillus presence, binary logistic regression analysis only showed gender and Lactobacillus as strongly associated with ECC. It can be concluded that gender and Lactobacillus presence are key variables for the presence of ECC in these children; whilst age and dental eruption stage play a minor role. Further studies are required to clarify the role of mutans streptococci counts in this population and to establish normal salivary parameters as well as threshold levels for hyprosalivation in preschool children, as results showed differences with normal parameters used for adults.     

Mutans streptococci and other caries-associated acidogenic bacteria in five-year-old children in South Africa

Correlations between mutans streptococci and caries are inconsistent; some studies show that early caries may occur with other bacterial species possessing the ability to survive, interact and compete with mutans streptococci. This study looked at the relationship between mutans streptococci, Lactobacillus, Actinomyces and Veillonella in saliva and plaque collected from four tooth sites in two ethnic groups, with and without caries. All samples were collected and cultured onto selective media. Colonies were enumerated and identified using biochemical tests. Pearson correlations showed low yet statistically significant correlations between plaque mutans streptococci counts and the number of decayed surfaces (ds) and decayed, missing and filled surfaces (dmfs) of primary teeth in blacks and in coloreds (historical race classification). Salivary mutans streptococci counts correlated with ds and dmfs in coloreds. No relationship was found between ds, dmfs and Lactobacillus, Actinomyces or Veillonella numbers. Significant associations were evident between plaque mutans streptococci and Veillonella and Lactobacillus in black children with caries and between plaque mutans streptococci and Actinomyces and Lactobacillus and Veillonella in colored children. Hence, oral microbes are in constant flux but have interrelationships in children with caries.