Effectiveness of fluoride varnish on caries in the first molars of primary schoolchildren: a 3-year longitudinal study in Guangxi Province, China

Cost-effectiveness and cost-benefit analyses of fluoride varnish for caries prevention in Guangxi, China

OBJECTIVES

The objectives of this study were to evaluate the cost-effectiveness and cost-benefit of fluoride varnish (FV) interventions for preventing caries in the first permanent molars (FPMs) among children in rural areas in Guangxi, China.

METHODS

This study constituted a secondary analysis of data from a randomised controlled trial, analysed from a social perspective. A total of 1,335 children aged 6-8 years in remote rural areas of Guangxi were enrolled in this three-year follow-up controlled study. Children in the experimental group (EG) and the control group (CG) received oral health education and were provided with a toothbrush and toothpaste once every six months. Additionally, FV was applied in the EG. A decision tree model was developed, and single-factor and probabilistic sensitivity analyses were conducted.

RESULTS

After three years of intervention, the prevalence of caries in the EG was 50.85%, with an average decayed, missing, and filled teeth (DMFT) index score of 1.12, and that in the CG was 59.04%, with a DMFT index score of 1.36. The total cost of caries intervention and postcaries treatment was 42,719.55 USD for the EG and 46,622.13 USD for the CG. The incremental cost-effectiveness ratio (ICER) of the EG was 25.36 USD per caries prevented, and the cost-benefit ratio (CBR) was 1.74 USD benefits per 1 USD cost. The results of the sensitivity analyses showed that the increase in the average DMFT index score was the largest variable affecting the ICER and CBR.

CONCLUSIONS

Compared to oral health education alone, a comprehensive intervention combining FV application with oral health education is more cost-effective and beneficial for preventing caries in the FPMs of children living in economically disadvantaged rural areas. These findings could provide a basis for policy-making and clinical choices to improve children's oral health.

Prevalence and contributing factors of malocclusion in Zhuang children aged 7-8 years in southern China

Introduction

Malocclusion, a common oral health problem in children, is associated with several contributing factors. This study aimed to investigate the prevalence of mixed dentition stage malocclusion and its contributing factors in Chinese Zhuang children aged 7-8 years.

Methods

Overall, 2,281 Zhuang children, about 7-8 years old, were randomly selected using a stratified whole-cluster sampling method from schools in counties in Northwestern Guangxi, China. The children were examined on-site for malocclusion and caries by trained dentists, and basic data on the children were collected using questionnaires, including age, sex, parental education, parental accompaniment, and children's knowledge of malocclusion and treatment needs. Data were analyzed using the chi-square test and logistic regression analysis.

Results

The total prevalence of malocclusion in Zhuang children aged 7-8 years was 58.5%, with the highest prevalence of anterior crossbite tendency, and the prevalence of anterior crossbite and anterior edge-to-edge occlusion was 15.1% and 7.7%, respectively. This was followed by an anterior increased overjet of 13.3% and an inter-incisor spacing of 10.3%. The lowest prevalence was 2.7% for anterior open bite. Sex, parental accompaniment, parental education, and decayed, missing, and filled teeth of the first primary molar were factors that contributed to malocclusion in Zhuang children.

Conclusion

Malocclusion is a common oral problem among Zhuang children. Therefore, more attention must be paid to the intervention and prevention of malocclusion. The impact factors should be controlled as early as possible.

[Influence of fluoride preparations for the prevention of dental caries on the enamel solubility]

OBJECTIVE

The aim of the study is to evaluate the effectiveness of a number of popular fluorine-containing caries prophylactic drugs by determining the level of solubility of tooth enamel in laboratory conditions.

MATERIAL AND METHODS

For testing fluorine-containing preparations, three observation groups were formed: Group I - using the preparation with the content of fluorides 4%; Group II - with a preparation for deep fluoridation of enamel, consisting of a liquid saturated with fluorine, copper and magnesium, as well as a suspension of calcium hydroxide; Group III - with a three-component gel based on carboxymethyl cellulose (CMC) the content of fluorides 1.5%. The study was carried out by using the method of «enamel windows» and modeling in the laboratory the processes of both natural and pathological solubility of tooth enamel and determining the level of its solubility by analyzing the decalcifying solution of the oral fluid for the content of calcium and phosphorus ions in it.

RESULTS

In the course of the study of fluorinated karyoprophylactic preparations on the enamel surface, according to the observation group, the most active karyoprophylactic fluorinated compositions were identified.

CONCLUSION

The data obtained from laboratory studies allow us to formulate clear recommendations for practical health care for the most effective use of the properties of the tested fluorine-containing drugs for prophylactic purposes or in relation to the therapy of focal demineralization of enamel: to obtain the most effective result of the prevention of dental caries in the conditions of practical dental treatment, we recommend applying gel fluoride preparations, and in the treatment of initial caries of the enamel of the teeth, give preference to systems for deep fluoridation of the enamel of the teeth.