A Comparative Evaluation of Bifidobacteria Levels in Early Childhood Caries and Severe Early Childhood Caries

Association between Bifidobacterium and Scardovia Wiggsiae and caries-related factors in severe early childhood caries and caries-free Thai children: a quantitative real-time PCR analysis and a questionnaire cross-sectional study

AIMS

To quantitatively identify Bifidobacterium, S. wiggsiae and S. mutans in plaque samples obtained from children with severe-ECC and caries-free groups and to analyze their association with caries-related factors retrieved from the questionnaire in each group.

STUDY DESIGN

To establish the 2 study groups, clinical examination in 122 Thai children, aged 2-5 years, recorded decayed, missing and filled teeth scores (dmft), in addition to plaque and gingival indices. Sixty one children in the caries-free group and 61 in the S-ECC group were identified. A questionnaire was used to assess the parent's attitudes and behavior regarding the child's oral hygiene care and diet.

METHODS

Pooled overnight supra gingival plaque was collected from each child using a sterile toothpick, released in 1 ml of TE buffer, transported on ice to the Laboratory and stored at  - 20 °C. DNA was extracted from the plaque based on enzymatic lysis and quantitative real-time PCR using fluorescent dye (SYBR green) in addition to Agarose gel electrophoresis were performed. All laboratory and retrieved from the questionnaire data per child were recorded and statistically analysed.

RESULTS

S. wiggsiae (p < 0.005) and S. mutans (p < 0.001) were higher in the S-ECC group. Bifidobacterium, S. mutans, and S. wiggsiae were associated with the dmft score and gingival index (p < 0.001). The dmft scores of children who detected only S. mutans were significantly lower than the dmft scores of children who detected two bacteria; S. mutans + S. wiggsiae (p = 0.028), S. mutans + Bifidobacterium (p = 0.026), and three bacteria; S. mutans + Bifidobacterium + S. wiggsiae (p = 0.007). Children who found all three bacteria (Bi + Sm + Sw) had the highest dmft scores, followed by children who had two bacteria (Bi + Sw, or Bi + Sm, or Sw + Sm). The guardians' education levels, occupations, household income, prolonged bottle feeding, taking of water after bottle or breast feeding, eating sugar-coated crackers or bread with sweetened cream, and premature birth were the factors that related to S-ECC.

CONCLUSION

Levels of S. wiggsiae and S. mutans, guardian's education, family economics, prolonged bottle feeding, eating high sugar-containing snacks and premature birth were associated with S-ECC.

The Association of Caries Increment Dynamics in Preschool Children with Risk Factors: The 3-Year Prospective Study

This prospective study monitored the dental status, the presence of plaque, and cariogenic microorganism levels of identical children over three years. The aim was to determine the dynamics of caries increment as well as the relationship between risk factors and caries prevalence. A total number of 125 children (72 boys and 53 girls) was included in the study, with an average age of 3.95 ± 0.06 years at the baseline. During the clinical examination at the nursery schools, the presence of dental plaque was recorded, and saliva samples were collected from the tongue of children for the DentoCult SM test providing easy detection of mutans streptococci from saliva samples. At baseline, 65.6% of the children had no caries, 4% had restored teeth with fillings or crowns or missing teeth due to caries, and 30.4% had at least one untreated caries. The percentages of intact teeth, restored or missing teeth, and untreated caries were 52.8%, 8.8%, 38.4% in the second year and 49.1%, 13.8%, and 31.1% in the third year. The dmft index value was 1.41 ± 0.24 in the first year, 2.29 ± 0.30 in the second year, and 2.33 ± 0.31 in the third year. There was a significant correlation between plaque presence and dt and dmft values (p < 0.05; the statistical analyses were performed using the Kolmogorov-Smirnov test). This 3-year longitudinal study highlighted the importance of examining both the oral hygiene and the level of cariogenic microorganisms when undertaking the evaluation of caries risk evaluation in preschool children.

The Oral Bacterial Microbiome of Interdental Surfaces in Adolescents According to Carious Risk

Adolescence is closely associated with a high risk of caries. The identification of specific bacteria in an oral microniche, the interdental space of the molars, according to carious risk can facilitate the prediction of future caries and the anticipation of the progression or stabilization of caries in adolescents. A cross-sectional clinical study according to the bacteriological criteria of interdental healthy adolescents and carious risk factors-low and high-using a real-time polymerase chain reaction technique was conducted. The presence of 26 oral pathogens from the interdental microbiota of 50 adolescents aged 15 to 17 years were qualitatively and quantitatively analyzed. Bacteria known to be cariogenic (Bifidobacterium dentium, Lactobacillus spp., Rothia dentocariosa, Streptococcus cristatus, Streptococcus mutans, Streptococcus salivarius, Streptococcus sobrinus, and Streptococcus wiggsiae) did not present differences in abundance according to carious risk. Periodontal bacteria from the red complex are positively correlated with carious risk. However, only 3 bacteria-S. sobrinus, E corrodens and T. forsythia-presented a significant increase in the highest group. Estimating the risk of caries associated with bacterial factors in interdental sites of molars in adolescents contributes to the better definition of carious risk status, periodicity and intensity of diagnostic, prevention and restorative services.