Pre- and post-treatment levels of salivary mutans streptococci and lactobacilli in pre-school children

Summary. Objectives . To examine the effect of operative and restorative treatment of dental caries on the levels of caries associated microorganisms in saliva and to relate alterations to the type and extent of treatment.
Design . Longitudinal.
Setting . Paediatric Dentistry Department at a central hospital in Sweden.
Subjects and methods . One hundred and eight pre-school children with severe dental caries scheduled for treatment under general anaesthesia. Chair-side tests were used to estimate the levels of salivary mutans streptococci, lactobacilli and buffer capacity before the surgery and at recall appointments 1 and 6 months after treatment. Caries were assessed according to WHO guidelines and the number of extracted teeth and filled surfaces during surgery were recorded.
Results . The results demonstrate that the post-treatment levels of mutans streptococci and lactobacilli were significantly reduced ( P < 0·001) compared to pretreatment levels. Lactobacilli levels were more dramatically reduced than mutans streptococci. The reduction of mutans streptococci was positively correlated to the number of extracted teeth ( P < 0·01), but not to the number of restored or ground surfaces. Lactobacilli reduction was not significantly related to the type of treatment.
Conclusion . The findings suggest that extensive operative and restorative dental care effectively reduces the levels of caries associated with microorganisms during a period of at least 6 months.     

Mutans streptococci and caries prevalence in preschool children

Abstract – Numerous studies have reported a correlation between mutans streptococci levels and dental caries. The aim of this study was to assess the relationship between salivary mutans streptococci levels and caries in preschool children of low socioeconomic status. A total of 462 Head Start children, mean age 3.8 yr (range 2.0-5.3 yr), were examined by the modified method of R adike . Saliva samples from 458 of these children were collected with tongue blades and impressed onto mutans streptococci selective agar. Children's mutans streptococci levels were categorized as low (0 CPU), moderate (1–50 CPU) or high (>50 CPU), and the mean dmfs was 0.40, 1.92 and 4.88, respectively. All study groups (Black, Hispanic and White) had infection rates of approximately 83%; however, 39.1% of Black children had high mutans streptococci levels compared with 28.4% of White children. Pit/fissure caries was the most prevalent disease type in children with moderate or high mutans streptococci levels, although White children in the high group had significantly less of this pattern than Blacks and Hispanics. Sensitivity, specificity, and positive and negative predictive values for the high mutans streptococci group were 91.3%, 57.5%. 69.3% and 86.3%. Results from this study indicate that differences between Black, Hispanic and While preschool children may influence caries activity within populations that have similar mutans streptococci infection levels and socioeconomic backgrounds.     

Mutans Streptococci and dental caries prevalence in a group of Latvian preschool children

Paraffin-stimulated saliva samples were collected from 140 children 3- and 4-yr old attending nine nursery schools in Latvia. The salivary levels of mutans streptococci were rated from zero to 3 after being cultured on a commercially available strip selective for these microorganisms. Of the children, 29.3% were rated at zero (～10⁴ cfu per ml saliva). This group of children demonstrated the lowest mean caries prevalence dmfs_tot= 1.5 (SD 1.9). The highest dmfs_tot was found among children in class 2 (38.6%; %10⁵-10⁶ cfu/ml) and class 3 (12.1% >10⁶ cfu/ml) with a mean caries prevalence of 6.5 (SD 5.8) and 6.4 (SD 6.0), respectively. The study demonstrates the association between high caries prevalence and high salivary levels of mutans streptococci in the young child. It is suggested that early identification of mutans streptococcicolonized children might be of value in selecting at caries risk children for preventive measures.     

Salivary levels of Bifidobacteria in caries‐free and caries‐active children

International Journal of Paediatric Dentistry 2013; 23: 32–38 Background Salivary levels of Bifidobacteria have been shown to be significantly correlated with caries experience in adults but not as yet in children. Hypothesis. Salivary levels of Bifidobacteria are positively associated with caries experience in children. Aim. To compare the salivary concentrations of Bifidobacteria of caries‐free and caries‐active children. Design. Saliva was collected using the tongue‐loop method from 38 caries‐active children and from 22 clinically caries‐free children, and the numbers of Bifidobacteria, mutans streptococci, lactobacilli and yeasts were determined. Additionally, the age and gender of the children, a plaque index, sugar amount in diet, sugar frequency in diet, hygiene practice and fluoride toothpaste usage were recorded. Results. Bifidobacteria were isolated from 95% of the caries‐active children and from only 9% of the caries‐free children (P < 0.001). Salivary levels of Bifidobacteria were significantly correlated with amount of sugar in the diet, frequency of sugar consumption and oral hygiene practice. The significant variables that discriminated between the caries‐free and caries‐active subjects were salivary levels of Bifidobacteria, salivary levels of mutans streptococci and oral hygiene practice (χ² = 72.57, P < 0.001) and overall 90.0% of cases were correctly classified. Conclusions. Salivary levels of Bifidobacteria are significantly associated with caries experience in children. The salivary levels of this genus may be a useful marker of caries risk.     

Prevalence of caries and salivary levels of mutans streptococci in 5-year-old children in relation to duration of breast feeding

Abstract – 144 children with a known breast feeding history were studied for their caries prevalence and level of salivary mutans streptococci. 19% of the children were exclusively breastfed for more than 9 months and 38% of the children were weaned after the age of 12 months (max. 34 months). The results of the study showed an equal caries prevalence at the age of 5 among children with a longer or shorter period of exclusive breast-feeding (x²= 3.68, 9 df, NS). Exclusive breast-feeding also did not affect the levels of salivary mutans streptococci (x²= 4.87, 9 df, NS). Children who were weaned late did not differ from those who were weaned early with respect to caries experience (x²= 6.12, 9 df, NS), level of salivary mutans streptococci (x²= 5.49, 9 df, NS) or presence of mutans streptococci (x²= 1.53, 4 df, NS). On the basis of our sample we concluded that breast feeding alone cannot be connected with an increased or lowered caries prevalence.     

Association of salivary mutans streptococci with discoloured pits and fissures

Experimental studies have demonstrated that mutans streptococci play a major role in caries etiology. Several previous epidemiologic studies found a positive association of salivary mutans streptococci with caries prevalence. The present epidemiologic study aimed at detecting a possible association of salivary mutans streptococci with brown discoloured pits and fissures, supposing that discolouration indicates caries. In the Canton of Zurich 1035 schoolchildren, aged 6.5–12.5, were examined with regard to caries prevalence and presence of discolourations in pits and fissures. A commercially available, semi-quantitative test was used to estimate the salivary level of mutans streptococci in each child. The salivary level (low/high) of mutans streptococci was significantly associated with the presence of slightly brown discoloured (C1), clearly brown discoloured (C2) and cavitated (C3) pits and fissures. The odds ratios were 1.5 ( P < 0.01) for C1, 2.5 ( P < 0.001) for C2 and 5.0 ( P < 0.001) for C3 pits and fissures. Then fidings are consistent with the hypothesis that brown discolouration indicates caries. Further-more, then fidings suggest that this type of discolouration at elementary school age indicates increased caries activity.     

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%).     

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.     

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.     

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.     

Oral sugar clearance and root caries prevalence in rheumatic patients with dry mouth symptoms.

The relationship between root caries, oral sugar clearance, salivary flow rate, and salivary counts of mutans streptococci, lactobacilli and candida has been studied in a group of 22 rheumatic patients (age range 40-72 years). The study group comprised all subjects volunteering for a clinical trial on relief of dry mouth symptoms. The median salivary flow was 0.09 ml/min at rest and 0.9 ml/min during chewing stimulation. The median sugar clearance time was about 5 min in the sublingual area and 16 min in the lower buccal vestibule. For subjects with 0-2 root caries lesions the clearance time at both sites was shorter than for subjects with 3 or more lesions (p < 0.05). A long oral clearance time was significantly correlated with age, root caries (DS and DFS), low resting salivary flow, and high salivary counts of mutans streptococci. It is concluded that root caries in rheumatic patients with low salivary flow is significantly related to oral sugar clearance time.     

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.     

Relationship of microbial and salivary parameters with dental caries in Brazilian pre-school children

Caries examination and collection of paraffin wax-stimulated saliva samples were performed in 37 children, 3-6 years old, in a child-care facility at the Vidigal slum, Rio de Janeiro, Brazil. The levels of mutans streptococci and lactobacilli in saliva were estimated by the Cariescreen and by the Dentocult tests and the saliva secretion rate was determined. Statistical analysis was performed on surface-based and patient-based caries prevalence rates (SBCPR and PBCPR), and related to bacterial and salivary parameters. The results show that 31 of the 37 children were caries active. The SBCPR for the primary dentition was 6.7% +/- 1.0%. Occlusal surfaces were the most affected by decay. Regression analysis revealed that mutans streptococci salivary levels were significantly associated with the SBCPR (P = 0.0001). Similarly, lactobacilli salivary levels were significantly associated with the SBCPR (P = 0.0001). No significant association could be found between the saliva secretion rate and the SBCPR. When regression analysis was used to model dependence of the SBCPR on both organisms, the mutans streptococci and lactobacilli salivary levels were significantly associated with the SBCPRs (P = 0.0021 and 0.0118, respectively), and salivary levels of these organisms accounted for 57% of the SBCPR variability. These findings indicate that the levels of mutans streptococci and lactobacilli in saliva are significantly related to the SBCPRs on the primary dentition of these children.     

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.     

Human leukocyte antigen class II alleles and dental caries in a child population

PURPOSE: The purpose of this study was to investigate a possible relationship between human leukocyte antigens (HLAs) DRB1 and DQB1, dental caries, and colonization by mutans streptococci (MS) in children. METHODS: Sixty children were clinically examined for caries in accordance with World Health Organization criteria and methods. Thereafter, subjects were assigned into 2 groups: (1) high-caries children (dft and DMFT > or = 5); and (2) caries-free children (dft and DMFT = 0). Fresh saliva samples were collected and testedfor mutans streptococci, after which the subjects were placed into 2 groups, having either high (> or =10(5) colony-forming units [CFU]/mL saliva) or low (< 10(5) CFU/mL saliva) numbers of micro-organisms in saliva. The polymerase chain reaction/sequence specific primer method was used to determine HLA DNA typing from fresh blood samples. RESULTS: There was no significant difference between the frequency of HLA alleles in high-caries and caries-free subjects. Although chi-square test suggested an association for HLA-DRB1*01 and HLA-DQB1*03 with the salivary numbers of MS (P = .026 and P = .009, respectively), these could not be confirmed by logistic regression analysis (P = .188 and P = .101, respectively). CONCLUSIONS: The results obtained fail to establish an association between human leukocyte antigen alleles DRB1 and DQB1 and salivary numbers of MS in the selected child population.     

Comparison of levels of mutans streptococci and lactobacilli in children with nursing bottle caries,rampant caries,healthy children with 3-5 dmft/DMFT and healthy caries free children

Ten children from each group of nursing caries, rampant caries, 3-5 dmft/DMFT and caries free children were selected and plaque samples from carious lesion, early carious lesion, sound tooth surface as well as salivary sample were collected. The levels of mutans streptococci and lactobacilli were estimated at all the sample sites. The result further supported the role of mutans streptococci in the initiation and of lactobacilli in the progression of the dental caries.     

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 and lactobacilli in saliva after the application of fissure sealants

Because dental fissures may serve as reservoirs for mutans streptococci, preventive measures should be taken to control microbial concentrations at these sites. This study estimated the influence that sealing permanent first molars would have on the levels of mutans streptococci and lactobacilli in saliva of healthy seven-year-old schoolchildren. Permanent first molars were sealed in 31 children without caries (NC group) and in 32 children with caries (C group). None of the children had caries in their permanent first molars. Conventional methods were used to count mutans streptococci and lactobacilli in saliva before applying the sealant and again at 4 and 12 weeks after application. Baseline counts of lactobacilli and mutans streptococci were significantly higher in the C group. A significant reduction in mutans streptococci was observed in the NC group at 4 and 12 weeks. It was concluded that fissure sealants in permanent first molars can help reduce salivary levels of mutans streptococci in children without caries.     

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.