Long-term Effectiveness of Integrated Caries Preventive Programs in Thailand Among Preschool Children Using a System Dynamics Model.

OBJECTIVE: To compare the effect of three caries preventive interventions provided by Thailand's Ministry of Public Health (MOPH): supervised toothbrushing (STB), fluoride varnish (FV), and combined STB+FV from 0 to 5 years old to the base case using the System Dynamics Model (SDM). METHODS: The SDM was developed to compare the intervention scenarios: STB, FV, and combined STB+FV with the base case scenario. Meta-analyses determined the effective rates of the interventions included in the model. RESULTS: The model indicated that the population with no caries in deciduous teeth increased by 7.5%, 5.7%, and 4.2% at three years of age, and 12.8%, 9.9%, and 5.9% at five years of age, under STB+FV, STB, and FV respectively when compared to the base case. At three years old, the population with untreated caries in deciduous teeth decreased by 12.9% in STB+FV, 9.8% in STB, and 7.3% in FV, and by 10.9% in STB+FV, 8.5% in STB, and 4.9% in FV, at five years old. The increase in the population without caries is considered clinically significant compared to baseline. CONCLUSION: The model determined that an effective combination of STB and FV should be administered between 0 and 5 years of age to reduce caries in the primary dentition. The SDM could be applied as a "what-if" analysis in order to determine the most beneficial intervention or policy by comparing them.

A randomized controlled trial of cluster audit and feedback on the quality of dental sealant for rural schoolchildren.

THE OBJECTIVE: To examine whether audit and feedback could improve the quality of the application of dental sealant in rural Thai school children. RESEARCH DESIGN: A single blind, cluster randomized controlled trial was conducted. CLINICAL SETTING: Hospital-based and school-based school sealant applied by dental nurses in Southern province of Thailand. PARTICIPANTS: Dental nurses and school children who received dental sealant were involved. INTERVENTION: The intervention consisted of confidential feedback of data and tailor-made problem-solving workshops. MAIN OUTCOME MEASURES: Sealant quality was measured by sealant retention and caries on sealed surfaces at six-month after sealing. The teeth examinations were done among different groups of children prior and after the intervention. RESULTS: After the intervention, the sealant retention rate increased dramatically in the intervention group, whereas in the control group the rate was similar to that found at baseline. The rate of caries after the intervention was stable in the intervention group and increased slightly in the control group. At the beginning of the study, the adjusted odds ratio of complete sealant retention between the intervention and control group was 0.47 which increased to 1.99 at the end of the study. However, no effect on caries on sealed surfaces was observed. CONCLUSIONS: The intensive focus on actual problems during the audit and feedback improved the dental nurses' performance and the quality of the dental service, although it had no statistical impact on the incidence of caries.

Lactobacillus species and genotypes associated with dental caries in Thai preschool children.

Lactobacilli have been associated with the presence and progression of dental caries. Nevertheless, the relation between certain species or genotypes of Lactobacillus and caries is unclear and there are no data available for the Thai population. This study aimed to examine the distribution of species and genotypes of oral Lactobacillus among children with rather high caries prevalence, and to investigate whether certain species or genotypes were more related to caries activity than others. One hundred and sixty-five children were examined for caries status. Saliva samples were collected and the numbers of lactobacilli were counted. A total of 357 Lactobacillus isolates from 59 children were identified to species level by 16S ribosomal RNA genes polymerase chain reaction (PCR) -restriction fragment length polymorphism and 16S ribosomal RNA gene sequencing. Furthermore, 304 isolates from 56 children were genotyped using arbitrarily primed PCR. Significant correlation was found between levels of lactobacilli and dental caries (P < 0.001). Among the 10 identified species of Lactobacillus, L. salivarius was more prevalent in children with moderate to high caries prevalence compared with children with low caries prevalence, while L. fermentum was the most predominant species in all study groups. Moreover, a genetic heterogeneity of Lactobacillus species was found among the children and those with high caries prevalence tended to be colonized with more than one clonal type. In summary, L. salivarius may be a putative caries pathogen among preschool Thai children.

Risks for early childhood caries analyzed by negative binomial models.

Because of the high incidence of early childhood caries (ECC), a longitudinal study to identify risk factors from the prenatal period to the child's first birthday among 9- to 18-month-old children was conducted with negative binomial modeling. Overall, 495 children had dental examinations at ages 9, 12, and 18 months. Mothers were interviewed during the 2nd trimester of pregnancy and when the children had dental examinations. The highest incidence of caries was found among children who were born to mothers with >or= 10 decayed teeth and who never received calcium supplements during pregnancy, and children who were not fed supplementary foods at age 3 months, had sweet-tasting foods at 5 months, started snacking at 5 months, had sugary snacks, had soft drinks, and did not have their teeth brushed daily at 9 months. Thus, prenatal care and child-rearing-practices during and after birth are important risk factors for the incidence and incremental rate of ECC.

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.