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.

Loss of sealant retention and subsequent caries development.

OBJECTIVES: To assess the transition process of sealant retention and to determine the effect of sealant loss on subsequent caries. RISK DESIGN: A follow-up study from the day sealants was applied by dental nurses, every six months over a period of 30 months. SETTING: Mobile dental clinics at primary schools in Songkhla, Thailand. PARTICIPANTS: 206 first grade primary school children, with 383 first permanent molars. OUTCOME MEASURES: Intermediate outcomes were: three categories of sealant retention: full retention, partial retention and missing sealant. The final outcome was whether occlusal caries was present or not. RESULTS: The percentages of occlusal surfaces of first permanent molars which were at risk (caries free) at time points 6, 12, 18, 24 and 30 months which became carious during the subsequent six months were 2.4, 8.00, 7.4, 5.4 and 6.1 respectively. Caries incidence was highest in the first year after sealing. Odds ratio of conversion from non-caries to caries between partial retention and missing sealant was 3.07 and between full retention and missing sealant, 0.27. CONCLUSION: Under high caries risk and low retention rate settings, partial retention posed a high risk of caries, suggesting an urgent need to improve sealant performance.