Community-based Interventions to Prevent Dental Caries among Kindergarten Children in Vietnam: A 12-month Study of Field Trial

INTRODUCTION

The 2017 Global Burden of Disease Study estimates that oral diseases affect nearly 3.5 billion people worldwide, without any significant improvement between 1990 and 2017, about 2.3 billion people have permanent dental caries, and more than 530 million children have molar decay.¹ In the context of the coronavirus disease-2019 (COVID-19) pandemic, oral health services are among the most impacted essential health services, with 77% of countries around the world experiencing partial or complete disruption.² Therefore, in September 2020, the 148th meeting of the WHO Executive Committee recommended the adoption of the resolution “Achieving better oral health as part of universal health and noncommunicable disease agendas toward 2030.”³

Dental caries is one of the most common and difficult-to-control chronic infections in children, characterized by its early onset of teething.⁴ Primary teeth hold a very important function of digesting food for children by cutting, chewing, and crushing food. Children with caries at an early age are at high risk of developing new caries in both primary and permanent teeth, affecting their quality of life later on.^5–8 Recent studies in Vietnam have recorded a very high rate of dental caries in children aged 3–6-year-old, 71.3%; in children aged 24–71 months, the rate of early childhood caries is up to 92.7%.^9,10

Today, thanks to researches that have identified the causes and pathogenesis of dental caries, along with the application of advanced equipment and methods; new diagnostic criteria have allowed for early detection of caries. It is these advances that have led to a change in the prevention and treatment of dental caries in order to reduce the costs and increase treatment effectiveness.^4,11

The role of fluoride in general and fluoride varnish in particular in the prevention and treatment of caries is increasingly understood and affirms the contributions of fluoride in reducing the rate and severity of dental caries globally.^12–14 In addition to fluoride, numerous studies have demonstrated that additional combinations of public health interventions can be scaled up to prevent and delay the development of caries and enhance resistance to caries damage. These interventions should be carried out for lifetime and should be individualized by age.¹⁵ A systematic review of Cochrane data published in 2016 with 38 studies from 1996 to 2014 on community interventions in 119.789 children concluded that the ability to integrate interventional strategies and specific activities (such as supervised oral hygiene practices, application of fluoride varnishes, and oral health education) can ameliorate primary dental caries in young children.¹⁶

In Vietnam in general and Hue City in particular, kindergarten dentistry has been implemented since 1980 with dental education. However, this program mainly focused on primary kindergarten age while kindergarten age has not been given much attention, especially in the prevention of early childhood caries. Recent studies show that the rate of dental caries in children is still high. A survey by Nguyen et al. in 2018 showed some factors related to dental caries in children aged 2–5 years, such as the mother’s educational level, the child’s habit of food pocketing and frequent sweet consumption, etc.^17,18 However, evidence of the effectiveness of the intervention in reducing dental caries in this population, especially the community-based intervention, was still lacking in Vietnam.

It is extremely important to assess the situation, propose preventive measures as well as treat dental caries at kindergarten age. Education to change behavior, create oral hygiene habits, and educate children and caregivers on dental knowledge, with the aim of reducing the rate of dental caries for kindergarten children. The health of primary teeth affects the development and shape of permanent teeth and therefore contributes to helping children have healthy teeth when they grow up. The objective of the study is to evaluate the status and effectiveness of dental caries prevention interventions in children from 3 to 5-year-old in Hue city, Vietnam.

MATERIALS AND METHODS

RESULTS

DISCUSSION

Our study used two criteria to evaluate dental caries, namely the percentage of kindergarten children with decayed, missing, filled teeth and decayed, missing, and filled teeth (DMFT) index. In 1997, the World Health Organization recognized this indicator and released a global guideline for practice.²¹ The research results showed that the rate of children with dental caries was very high, at 77.2%. There was no relationship between dental caries and children’s characteristics except age (Table 1). This result was similar to the study of domestic authors.^8,16,22 However, our rate of dental caries was higher than that of some studies by authors around the world in 3–5-years-old, such as Ghandahari-Motlagh in Tehran-Iran at 51.7%, Vejdani in Rasht, Iran at 43.5%.^23,24 Children of 3–5-years-old in China have a higher rate of dental caries; Zhang was 76.3% and Zhou was 70.4%.^25,26 The reason leading to high dental caries in children is often due to many objectives as well as subjective factors, such as improper bottle feeding, eating an excessive amount of foods containing sugar (milk, candies, soft drinks…), late start of toothbrushing, not receiving proper care, and lack of fluoride in water source.^27–30 Moreover, until now, the kindergarten dental program in Vietnam has focused mainly on primary kindergarten students.³¹

The average DMFT in our study was 9.00 which was similar in different kindergartens in Hue City because of the similarity in socioeconomic conditions, customs and conditions, as well as the conditions of medical services. The study showed that the average index of decayed teeth in children in the study was very high (d: 8.25), while the average of filled teeth was very low (f: 0.48) (Table 2).This showed that parents have not paid enough attention to dental care for children at kindergarten age, the age at which many parents think that primary teeth are temporary and will change when the child gets older.^32,33 This result was similar to the study of Nguyen which was 9.32 (d: 9.21; m: 0.04; f: 0.11), Nhung (10.32), and Khodadadi conducted a study on 384 children from 21 to 84 months old in Babol, Iran, in 2016; the results showed the index of decayed, missing, and filled teeth was 6.5, 0.4, and 1.2, respectively, and the overall index was 8.2.^10,17,34 According to the results of Table 2, the dental caries rate was also very high, but the filled rate was very low. Therefore, it is important to have a fixed dental office with the function of treating and preventing dental caries at kindergarten. Furthermore, it is necessary to enhance the role of oral health education for parents of kindergarten-aged children.³⁵

Multivariable logistic regression analysis showed that factors reducing the risk of dental caries were brushing teeth two or three times a day, parent-assisted toothbrushing, and eating and drinking sweets rarely. However, age was likely to increase the risk of dental caries in the children (Table 3). The above results show common ground with the study of Thwin in Yangon, Myanmar; Jain in India, which showed that variables significantly associated with early caries in children were age (p <0.001), breastfeeding time/bottle (p <0.001), use of sweetened pacifiers (p <0.001), snacking frequency (p <0.05), toothbrushing frequency (p <0.001), the person responsible for taking care of the child’s oral health (p <0.05), and the educational level of the parents (p <0.05).^35,36 Children are generally less likely to have dental caries and have a lower severity if their parents’ teeth are self-rated as healthy. They will be more conscious of taking care of their teeth and building a cavity-fighting diet for their children.³⁷ The assessment of the above-related factors helped us focus on interventions with more appropriate measures.

We conducted an interventional model that includes both immediate and long-term measures to prevent dental caries in children. Specific interventions: Strengthening oral health education and communication, instruction on proper toothbrushing, advising teachers and parents to limit the use of sugar in the diet, and limiting snacks between meals, parents’ cooperation in forming children’s brushing habits, use of fluoride varnish to prevent dental caries, presentation of propaganda pictures about dental disease, and the harmful effects of dental caries and prevention methods in kindergarten yard and classrooms with insurance of esthetic and visual effect. The above measures were consistent with WHO 2019 guidelines for the prevention of childhood caries.³⁸

Besides the treatment intervention for children with caries, we also conducted a 12-month educational intervention in the community with the participation of the kindergarten children and their parents. This intervention helped us strengthen the sustainability of dental caries prevention. After 12 months of intervention, the rate of caries in the intervention group was statistically significantly lower than in the control group (RR = 0.89; 95% CI: 0.82–0.96) (Table 4). Although there were also new caries and recurrent caries in the intervention group. It is evident that there were many objective factors affecting the outcome of the intervention, for example, family income, parents’ educational level, especially the mothers’ knowledge and attitude toward their children’s oral health.^39,40 The percentage of children with gingivitis and plaque in the intervention group was significantly lower than that in the control group, which was also the success of measures to prevent dental caries because gingivitis and plaque are favorable factors that cause dental caries (Table 5). This result was also observed in kindergarten-based interventions in kindergarten children.^41,42 We used fluoride varnish in the intervention group twice a year. The effectiveness of fluoride varnishes (5% NaF) was demonstrated in numerous studies.^43,44 Another 2016 review by Bonetti et al. from 200 trials with more than 80,000 participants confirmed the effectiveness of fluoride varnish, used as indicated 2–4 times/year, to prevent dental caries in both primitive and permanent teeth.⁴⁵ However, one study found that the use of fluoride varnish twice yearly, although safe and accepted, did not significantly reduce the incidence of dental caries.^46,47 Therefore, it is still necessary to incorporate measures to prevent dental caries in young children according to WHO guidelines.³⁸

In order to have a more multidimensional assessment of the effectiveness of the prevention of dental caries and dental problems of the interventions in the study, we analyzed the effectiveness and efficiency index of interventions on dental caries and dental problems of kindergarten children before and 12 months after the intervention. The results in Table 5 showed that the rate of dental caries in the intervention group increased from 78.9 to 80.3% (effectiveness index = −1.8%), while the caries rate in the control group increased from 75.4 to 90.7% (effectiveness index = −20.3%). Therefore, the intervention efficiency was 18.5%. Effective intervention was clear on the two problems such as gingivitis and dental plaque. The rate of gingivitis in the intervention group decreased from 49.1 to 41.7% (effectiveness index = 15.1%), the rate of gingivitis in the control group increased from 59.3 to 66.1% (effectiveness index = −11.5%), and intervention efficiency was 26.6%. The rate of plaque in the intervention group decreased from 56.6 to 44.3% (effectiveness index = 21.7%), and the rate of plaque in the control group increased from 53.8 to 64.0% (effectiveness index = −19.0%), from which the intervention efficiency was 40.7%. Reducing the rate of gingivitis and dental plaque is very important by practicing proper and regular brushing. Oral health education program is effective in establishing good oral health habits for kindergarten children and increasing their parents’ knowledge of oral health, combined with supervised daily brushing using fluoride-containing toothpaste, which may reduce the development of new caries.⁴⁸ Breastfeeding is the best natural nourishment for an infant and it is essential for the healthy development of the child. Infants who were exclusively breastfed had fewer cavities at 24 months of age than formula-fed infants, and breastfeeding up to 2 years of age did not increase the risk of early dental caries.^30,49 Furthermore, the most recent recommendations from the pediatric and dental associations recommend breastfeeding for children until 2-years-old accompanied by brushing and good nutrition by reducing the frequency and consumption of sugary foods.⁵⁰ This will reduce the rate of early childhood caries.

Dental caries is a disease with many causes and risk factors. Therefore, with regard to the prevention and treatment of dental caries, we cannot only focus on modifying several aspects but a collection of numerous preventive measures as well as interventions is necessary to acquire the highest efficiency. Many interventional programs were implemented with successful evidences.^48,51 Our study alone used a community participation interventional model, combined with immediate and long-term caries prevention measures. The results of the study showed that it was effective when compared with the control group. However, in order to have sustainable success, there needs to be a specific strategy from the national level beginning as early as kindergarten age, in addition to the recent decision of the Vietnamese Ministry of Health on universal dental care until 2030.³¹

This study also has some limitations. In phase 1 of the study, we investigated a limited sample size of 464 children. Therefore, some factors may not be detected and intervened in the next stage. Kindergarten children may be difficult to absorb information from communication activities. Therefore, we have tried to design the media contents which are visually appealing and suitable for this age. Finally, future studies are needed to clarify more factors related to dental caries and assess better the effectiveness of the community intervention among kindergarten children in Vietnam.

CONCLUSION

The rate of dental caries among Vietnamese children is still very high. The most effective way to prevent early childhood dental caries would be through a comprehensive oral health intervention. Although childhood dental caries is a multifactorial disease, it can be prevented with a community-based and well-organized prevention program. Our intervention program was consistent with WHO guidelines with modifications to fit local characteristics and adjusted for risk factors through multivariate analysis.

ACKNOWLEDGMENTS

This study was funded by the Department of Science, Technology and International Relations—Hue University. Authors would like to thank the parents and children for their enthusiastic participation in the study. Authors also would like to thank the support and companionship of the kindergartens throughout the research process.

ETHICAL CONSIDERATIONS

Ethical issues including plagiarism, informed consent, misconduct, data fabrication and/or falsification, double publication and/or submission, and redundancy have been completely observed by the authors.

REFERENCES

1. Bernabe E, Marcenes W, Hernandez CR, et al. Global, regional, and national levels and trends in burden of oral conditions from 1990 to 2017: a systematic analysis for the global burden of disease 2017 study. J Dent Res 2020;99:362–373. DOI: 10.1177/0022034520908533.

2. World Health Organization. Pulse survey on continuity of essential health services during the COVID-19 pandemic: interim report, 27 August 2020, Geneva, 2020.

3. World Health Organization. Oral health: achieving better oral health as part of the universal health coverage and noncommunicable disease agendas towards 2030, Geneva, 2020.

4. Douglass JM, Douglass AB, Silk HJ. A practical guide to infant oral health. Am Fam Physician 2004;70:2113–2120. PMID: 15606059.

5. André Kramer AC, Skeie MS, Skaare AB, et al. Caries increment in primary teeth from 3 to 6 years of age: a longitudinal study in Swedish children. Eur Arch Paediatr Dent 2014;15:167–173. DOI: 10.1007/s40368-013-0079-7.

6. Ghazal T, Levy SM, Childers NK, et al. Prevalence and incidence of early childhood caries among African-American children in Alabama. J Public Health Dent 2015;75(1):42–48. DOI: 10.1111/jphd.12069.

7. Filstrup SL, Briskie D, da Fonseca M, et al. Early childhood caries and quality of life: child and parent perspectives. Pediatr Dent 2003;25:431–440. PMID: 14649606.

8. Singh N, Dubey N, Rathore M, et al. Impact of early childhood caries on quality of life: child and parent perspectives. J Oral Biol Craniofac Res 2020;10:83–86. DOI: 10.1016/j.jobcr.2020.02.006.

9. Van Tam V, Huu Nhan N, Quy Tinh H. Dental caries situation of preschool children aged from 3 to 6 in Van Xuan commune, Vinh Tuong district, Vinh Phuc province, Vietnam. VNU J Sci Nat Sci Technol 2017;33. DOI: 10.25073/2588-1140/vnunst.4538.

10. Nhung NT, Kien NT, Đinh TK. The early childhood caries in preschool children with age 24–71 months in urban Can Tho, Viet Nam. Can Tho J Med Pharm 2019;19:1–7.

11. Lee Y. Diagnosis and prevention strategies for dental caries. J Lifestyle Med 2013;3(2):107–109. PMID: 26064846.

12. Jagan P, Fareed N, Battur H, et al. Effectiveness of sodium fluoride mouthrinses on the prevention of dental caries: a systematic review. J Indian Assoc Public Health Dent 2015;13:110–115. DOI: 10.4103/2319-5932.159042.

13. Tuong LV. Dental caries status and evaluation of the effectiveness of the treatment of early childhood caries in 3-year-old children with fluoride varnish in Hanoi city, Vietnam [MD thesis]. Hanoi Medical University; 2020.

14. Marinho VC, Worthington HV, Walsh T, et al. Fluoride varnishes for preventing dental caries in children and adolescents. Cochrane Database Syst Rev 2013;(7):CD002279. DOI: 10.1002/14651858.CD002279.pub2.

15. Horst JA, Tanzer JM, Milgrom PM. Fluorides and other preventive strategies for tooth decay. Dent Clin N Am 2018;62:207–234. DOI: 10.1016/j.cden.2017.11.003.

16. de Silva AM, Hegde S, Akudo Nwagbara B, et al. Community-based population-level interventions for promoting child oral health. Cochrane Database Syst Rev 2016;9:Cd009837. DOI: 10.1002/14651858.CD009837.pub2.

17. Nguyen YHT, Ueno M, Zaitsu T, et al. Early childhood caries and risk factors in Vietnam. J Clin Pediatr Dent 2018;42. DOI: 173-181.10.17796/1053-4628-42.3.2.

18. Minh NTH, Hai TD. Primitive caries in Vietnamese children in 2019. Vietnam J Prevent Med 2020;30:123–129. https://doi.org/10.51403/0868-2836/2020/306.

19. Hoat LN, Thang VV. Research methods for community health. Hue University Publishing House; 2011.

20. World Health Organization. Oral health surveys: basic methods. 5th ed. Geneva: World Health Organization; 2013.

21. World Health Organization. Oral health surveys : basic methods. Geneva: World Health Organization; 1997.

22. Huong DM, Hang LTT. Early dental caries among 19.5 kindergarten children in Thai Nguyen city, Vietnam according to ICDAS II, Mountainous Med Pharm Bull 2016;2:61–68.

23. Ghandahari-Motlagh M, Zeraati H. Dental health status in 3-5 year old kindergarten children in Tehran-Iran in 2003. J Dent Tehran Univ Med Sci 2005;2(1):18.

24. Vejdani J, Janeshin A, Heidarzadeh A, et al. The association between body mass index and gross dental caries in a population of 3- to 5-year-old children attending kindergartens in Rasht, Iran. Caspian J Dent Res 2022;11:15–20. DOI: 10.22088/cjdr.11.1.15.

25. Zhang K, Li J, Lu Z. The prevalence of dental caries in primary dentition in 3- to 5-year-old preschool children in northern China. BioMed Res Int 2020;2020:5315236. DOI: 10.1155/2020/5315236.

26. Zhou N, Zhu H, Chen Y, et al. Dental caries and associated factors in 3 to 5-year-old children in Zhejiang Province, China: an epidemiological survey. BMC Oral Health 2019;19:9–9. DOI: 10.1186/s12903-018-0698-9.

27. Senesombath S, Nakornchai S, Banditsing P, et al. Early childhood caries and related factors in Vientiane, Lao PDR. Southeast Asian J Trop Med Public Health 2010;41(3):717–725. PMID: 20578562.

28. Slabsinskiene E, Milciuviene S, Narbutaite J, et al. Severe early childhood caries and behavioral risk factors among 3-year-old children in Lithuania. Medicina (Kaunas, Lithuania) 2010;46(2):135–141. PMID: 20440088.

29. Tenelanda-López D, Valdivia-Moral P, Castro-Sánchez M. Eating habits and their relationship to oral health. Nutrients 2020;12:2619. DOI: 10.3390/nu12092619.

30. Moynihan P, Tanner LM, Holmes RD, et al. Systematic review of evidence pertaining to factors that modify risk of early childhood caries. JDR Clin Transl Res 2019;4:202–216. DOI: 10.1177/2380084418824262.

31. Vietnam Ministry of Health Decision on approving the project on capacity building for odonto-stomatology and prevention of community oral diseases in the 2021-2030. No. 5628/QD-BYT December 9,2021. Hanoi, 2021.

32. Vittoba Setty J, Srinivasan I. Knowledge and awareness of primary teeth and their importance among parents in Bengaluru City, India. Int J Clin Pediatr Dent 2016;9:56–61. DOI: 10.5005/jp-journals-10005-1334.

33. Ramakrishnan M, Banu S, Ningthoujam S, et al. Evaluation of knowledge and attitude of parents about the importance of maintaining primary dentition–a cross-sectional study. J Fam Med Prim Care 2019;8(2):414–418. DOI: 10.4103/jfmpc.jfmpc_371_18.

34. Khodadadi E, Niknahad A, Sistani MM, et al. Parents’ oral health literacy and its impact on their children’s dental health status. Electron Phys 2016;8:3421–3425. DOI: 10.19082/3421.

35. Thwin K, Zaitsu T, Ueno M, et al. Early childhood caries and related risk factors among Myanmar preschool children. Int J Clin Prevent Dent 2016;12:229–236. DOI: 10.15236/ijcpd.2016.12.4.229.

36. Jain M, Namdev R, Bodh M, et al. Social and behavioral determinants for early childhood caries among preschool children in India. J Dent Res Dent Clin Dent Prospects 2015;9:115–120. DOI: 10.15171/joddd.2014.023.

37. Olczak-Kowalczyk D, Gozdowski D, Turska-Szybka A. Protective factors for early childhood caries in 3-year-old children in Poland. Front Pediatr 2021;9:583660. DOI: 10.3389/fped.2021.583660.

38. World Health Organization. Ending childhood dental caries: WHO implementation manual. Geneva: World Health Organization; 2019.

39. Finlayson TL, Cabudol M, Liu JX, et al. A qualitative study of the multi-level influences on oral hygiene practices for young children in an Early Head Start program. BMC Oral Health 2019;19:166. DOI: 10.1186/s12903-019-0857-7.

40. Rai NK, Tiwari T. Parental factors influencing the development of early childhood caries in developing nations: a systematic review. Front Public Health 2018;6:64. DOI: 10.3389/fpubh.2018.00064.

41. Hochstetter AS, Lombardo MJ, D’Eramo L, et al. Effectiveness of a preventive educational programme on the oral health of preschool children. Promot Educ 2007;14(3):155–158. PMID: 18154225.

42. Ramseier CA, Leiggener I, Lang NP, et al. Short-term effects of hygiene education for preschool (kindergarten) children: a clinical study. Oral Health Prev Dent 2007;5:19–24. PMID: 17366757.

43. Marinho VC, Higgins JP, Sheiham A, et al. One topical fluoride (toothpastes, or mouthrinses, or gels, or varnishes) versus another for preventing dental caries in children and adolescents. Cochrane Database Syst Rev 2004;2004:Cd002780. DOI: 10.1002/14651858.CD002780.pub2.

44. Weintraub JA, Ramos-Gomez F, Jue B, et al. Fluoride varnish efficacy in preventing early childhood caries. J Dent Res 2006;85:172–176. DOI: 10.1177/154405910608500211.

45. Bonetti D, Clarkson JE. Fluoride varnish for caries prevention: efficacy and implementation. Caries Res 2016;50 Suppl 1:45–49. DOI: 10.1159/000444268.

46. Oliveira BH, Salazar M, Carvalho DM, et al. Biannual fluoride varnish applications and caries incidence in preschoolers: a 24-month follow-up randomized placebo-controlled clinical trial. Caries Res 2014;48:228–236. DOI: 10.1159/000356863.

47. de Sousa FSO, Dos Santos APP, Nadanovsky P, et al. Fluoride varnish and dental caries in preschoolers: a systematic review and meta-analysis. Caries Res 2019;53:502–513. DOI: 10.1159/000499639.

48. Rong WS, Bian JY, Wang WJ, et al. Effectiveness of an oral health education and caries prevention program in kindergartens in China, Commun Dent Oral Epidemiol 2003;31:412–416. DOI: 10.1046/j.1600-0528.2003.00040.x.

49. Deghatipour M, Ghorbani Z, Mokhlesi AH, et al. Community-based interventions to reduce dental caries among 24-month old children: a pilot study of a field trial. BMC Oral Health 2021;21:637. DOI: 10.1186/s12903-021-01999-x.

50. Branger B, Camelot F, Droz D, et al. Breastfeeding and early childhood caries. Review of the literature, recommendations, and prevention. Arch Pediatr 2019;26(8):497–503. DOI: 10.1016/j.arcped.2019.10.004.

51. Shirzad M, Taghdisi MH, Dehdari T, et al. Oral health education program among pre-school children: an application of health-promoting schools approach. Health Promot Perspect 2016;6:164–170. DOI: 10.15171/hpp.2016.26.