Original ArticleBraz J Oral Sci. April/June 2009 - Volume 8, Number 2 Dental caries experience in preschool children of Bauru, SP, Brazil Fábio Silva de Carvalho1, Cristiane Alves Paz de Carvalho1, Roosevelt da Silva Bastos1, Angela Xavier2, Sabrina Pulzatto Merlini3, José Roberto de Magalhães Bastos4 1 DDS, MS, Graduate student, Department of Pediatric Dentistry, Orthodontic and Public Health, Faculdade de Odontologia de Bauru, Universidade de São Paulo (USP), Bauru (SP), Brazil 2 DDS, Undergraduate student, Department of Pediatric Dentistry, Orthodontic and Public Health, Faculdade de Odontologia de Bauru, USP, Bauru (SP), Brazil 3 DDS, Department of Pediatric Dentistry, Orthodontic and Public Health, Faculdade de Odontologia de Bauru, USP, Bauru (SP), Brazil 4 DDS, MS, PHD, Professor, Department of Pediatric Dentistry, Orthodontic and Public Health, Faculdade de Odontologia de Bauru, USP, Bauru (SP), Brazil Received for publication: April 29, 2009 Accepted: July 24, 2009 Correspondence to: Fábio Silva de Carvalho Universidade de São Paulo Department of Pediatric Dentistry, Orthodontic and Public Health Alameda Octávio Pinheiro Brisolla, 9-15 CEP 17012-901 – Bauru (SP), Brasil E-mail: fasicar@usp.br Abstract Aim: The main purpose of this study was to evaluate dental caries experience and prevalence in three to six-year- old preschool children from three public kindergartens of the city of Bauru, SP, Brazil. Methods: The sample com- prised 283 children (142 boys; 141 girls) aged 3 to 6 years old. For data analysis, the dmft (decayed, missing and filled teeth), Significant Caries Index (SiC Index), percentage of caries-free children, Gini Coefficient and Care Index were determined. Mann-Whitney and Kruskal-Wallis tests were used with 5% significance. Results: The mean (SD) dmft index was 1.40 (2.63). Among the examined children, 63.25% were caries-free. The decayed component comprised 77.28% of the dmft. The Care Index was 19.70%, indicating limited utilization of dental treatment by children. The SiC index was 4.11 and the Gini Coefficient was 0.78 in the survey. The results showed that there were no statistically significant differences in the prevalence of the disease between the ages and between males and females. Conclusions: Dental caries experience and prevalence in preschool children were considered low in this study and the occurrence of polarization of the disease was identified. Keywords: dental caries, child, preschool, oral health. Introduction The fluoridation of the public water supply since the 1970s and the massive use of fluoridated dentifrices from the 1980s are scientifically recognized as the main responsible factors for dental caries decline in the last decades1,2. In spite of this, a heterogeneous distribution of dental caries has been observed, in which high disease levels have been identified in a minor- ity of individuals3. Studies directed to primary dentition did report the same decline in the prevalence of caries and, additionally, reported an increase in the mean dmft, with high proportions of untreated caries4-8. In Brazil, few studies on caries prevalence in primary teeth have been developed over the last years. Age is an important factor to be regarded in order to better understand children’s oral health in the primary dentition since past caries experience is considered as the most powerful predictor of the disease9-11. Epidemiological dental studies have shown changes in the distribution of dental caries and this trend has been investigated4,6-8,11. Epidemiological 98 Carvalho FS, Carvalho CAP, Bastos RS, Xavier A, Merlini SP, Bastos JRM Braz J Oral Sci. 8(2): 97-100 data would allow oral health administrators to plan specific mea- sures according to oral health needs. Due to the abovementioned considerations, the main purpose of this study was to evaluate dental caries experience and prevalence in three to six-year-old preschool children in three public kindergar- tens in the city of Bauru, SP, Brazil. Material and methods This epidemiological study was carried out in the city of Bauru, lo- cated in the State of São Paulo, Brazil, which had an estimated popu- lation of 355,675 in 200812. Fluoride has been added to water supply since 1975 in Bauru (0.07 ppm). The research protocol was approved by the Institutional Review Board (IRB) of Bauru Dental School, University of São Paulo, Brazil, (process no 71/2008), and the autho- rization for conduction of study was obtained from the municipal secretary education and directors of kindergartens. Also, written in- formed consent was obtained from the parents/legal representatives prior to enrolment of the children. Sample This study provided epidemiological data for the development of educational and preventive program in oral health in three public kindergartens. Information about total number of students in each unit by age was obtained from the directors of the kindergartens. There was a return rate of 77.43% (319 out of 412) of signed consent forms from parents/legal representatives. However, the final sample was reduced, since 36 children were absent on the examination day or refused to be examined despite the parents’ consents. The study was conducted with 283 preschool children, 142 boys and 141 girls, aged 3 to 6 years old, corresponding to 68.69% of the total number of children in the three kindergartens. Examination methodology The exams were done with the children seated on chairs under natu- ral light. Materials used were dental mirror and CPI (Community Periodontal Index) probe13. The clinical examinations used for obser- vation of the mean number of decayed, missing or filled teeth (dmft index) were performed according to the criteria established by the World Health Organization (WHO)13. Only one examiner was trained and calibrated for this study. During data collection, duplicate ex- aminations of approximately 10% of the sample were performed to assess intra-examiner variability. Intra-examiner agreement for dental caries diagnosis was evaluated by means of the kappa coef- ficient, showing values of 0.92, whose agreement was considered to be excellent. Data analysis Percentages of caries-free children and dmft were used to describe dental caries distribution among children. Significant Caries Index14 (SiC Index), Gini Coefficient15 and Care Index16 were adopted to as- sess the unequal distribution of dental caries and oral health care. SiC index was calculated by taking the mean dmft of the one- third of the individuals having the highest of dmft values in a given population14, and was used to measure the polarization of the dental caries occurrence among children. The Care Index16 was calculated using the means dmft without caries-free. The component “f ” (filled teeth) was divided by the dmft and multiplied by 100. The Gini Co- efficient was used to assess inequality of caries distribution in this study15. Mann-Whitney and Kruskal-Wallis non-parametric tests were used to check the statistical association between the studied vari- ables. A significance level of 5% was adopted. Results Table 1 shows the caries experience according to age and gender. From the group of examined children, 179 (63.25%) were caries-free. Homogenous distribution, according to gender, was observed in this sample. The mean dmft was 1.40 to total sample. The boys had dmft greater than girls. The mean dmft was 1.13 at 3 years of age and 1.68 at 6 years of age. No statistically significant differences (p > 0.05) were found in this study with regard to the prevalence of disease among gender and age. The decayed component comprised 77.28% of the dmft and the filling component 19.70%. One third of the sample concentrated 97.47% of the dmft distribution in the respective study. The SiC in- dex was 4.11, the Care Index was 19.70% and the Gini Coefficient was 0.78. Discussion Data from the last Brazilian Oral Health Survey (SBBrasil 2003)17 showed dmft at 5 years of age of 2.80, which is similar to the results observed in other Brazilian cities, such as in Bilac18 (2.84), Piracica- Variables Sample Caries-free Mean dmft (sd) Age n % n % 3 32 11.30 21 65.62 1.13 (1.90) 4 97 34.28 63 64.95 1.42 (3.11) 5 104 36.75 64 61.54 1.33 (2.28) 6 50 17.67 31 62.00 1.68 (2.75) Total 283 100.00 179 - 1.40 (2.63) Gender Boys 142 50.18 87 61.27 1.65 (3.11) Girls 141 49.82 92 65.25 1.15 (2.03) Total 283 100.00 179 - 1.40 (2.63) DMFT: decayed, missing and filled teeth. Table 1. Caries experience according to age and gender, Bauru, Brazil, 2008 99Dental caries experience in preschool children of Bauru, SP, Brazil Braz J Oral Sci. 8(2): 97-100 ba19 (2.68), Rio Claro20 (2.50), Juiz de Fora21 (2.40) and Teresina22 (2.13). Mean dmft was lower in the cities of Paulínia23 (1.90), Campinas24 (1.68), Indaiatuba25 (1.62) and higher in the city of Cambira26 (3.51). In the present study, mean dmft was 1.33. Breaking the dmft index into decayed (“d”) and filled (“f ”) com- ponents revealed greater inequality in the distribution these compo- nents. At 5 years old, the decayed and filled represented respectively 78.99% and 18.12% of the dmft index. Higher values for the decayed (“d”) component were found in the cities of Indaiatuba25 (84.80%), Juiz de Fora21 (87.60%) and Cambira26 (92.30%), while lower values were found in the city of Campinas24 (75.60%). The access to health services is not satisfactory to the children that participated of this study yet, as demonstrated by the small number of filled teeth in relation to the number of decayed teeth, as reported elsewhere23. Considering the total sample, the Care index values reached 19.70%, indicating a low coverage of the oral health service for the studied preschool children, as observed in the cities of Indaiatuba25 (12.30%). Nevertheless, greater values were observed in Piracicaba19 (23.10%), Rio Claro20 (64.00%) and Paulínia23 (65.40%). The results of another investigation carried out in Bauru showed an improvement in the oral health service coverage among 12-year-old children in 2006, since Care index reached 56.30%27. In this study, at 5 years old, 61.54% of the preschool children were caries-free. Lower values were observed in the cities of Cambira26 (31.14%), Juiz de Fora (44.00%), Piracicaba19 (44.30%), Bilac18 (45.30%), Rio Claro20 (51.00%), Paulínia23 (54.20%), Teresina22 (55.70%) and Campinas24 (56.17%). As observed in Bilac18, Juiz de Fora21, Teresina22 and Cambira26, the number of children affected by caries disease increased with age, with a percentage of children with dmft > zero at six years old greater than that at three years old. The results also showed that 97.47% of the dmft distribution was concentrated in one third of the sample, which clearly demonstrated the phenomenon of caries polarization. This fact was not observed in the city of Teresina22, where approximately 49% of the children pre- sented caries. SiC index was developed in 2000 to bring attention to those chil- dren with the highest caries scores in each population28,29. In the pres- ent study, SiC index was used to identify the group with highest caries rate and the value of 4.11 was found, lower than that recorded in other cities such as Bilac18 (5.90), Itaí30 (5.08) and Água Doce31 (9.97). Inequalities in caries distribution were measured by the Gini co- efficient. This index indicate perfect inequality with a coefficient of 1 and perfect equality with a coefficient of 0. It has been used in a way to measure the association between exposure to a risk factor and disease prevalence15. A higher Gini coefficient means that the risk of disease is more variable amongst the population. In this study, the Gini Coefficient was of 0.78, which is similar to that obtained in a previous study carried out in Bauru27 involving 12-year-old children (0.76), indicating an unequal distribution of caries in this municipal- ity. This unequal distribution occurs due to different socioeconomic levels of the population according to Cypriano et al.32, and some fac- tors, such as local service organization, access to fluoridated water, preventive procedures and investment in public health, may change this trend. Acquaintance with inequalities in the distribution of child caries must inevitably invite the question as causes of this phenomenon. There are several risk factors for caries experience, for example, transmissibility of oral bacteria and amount and timing of exposure to cariogenic foodstuffs and drinks, and difficulty of access to dental services. It is important to mention that this study had some limitations. The sample was drawn from a population of three to six-year-old pre- school children attending three public kindergartens. Therefore, the conclusions are valid only for this population. The educational and preventive program in oral health may change the epidemiological profile of caries in preschool children from these kindergartens. In addition to the dmft index, other approaches for caries evaluation should be considered. The SiC index and Gini coefficient supply the oral health service epidemiological data that allows the promotion of adequate oral health based on the community needs. The interaction of health professionals, educators and parents, and the planning of strategies may reduce the inequality distribution of dental caries in children to advance the oral health patterns. In conclusion, dental caries experience and prevalence in pre- school children were considered low in this study, and the occur- rence of the polarization of the disease was identified. References 1. Truman BI, Gooch BF, Sulemana I, Gift HC, Horowitz AM, Evans CA, et al. Reviews of evidence on interventions to prevent dental caries, oral and pharyngeal cancers, and sports-related craniofacial injuries. Am J Prev Med. 2002;23(1 Suppl):21-54. 2. Bratthall D, Hänsel-Petersson G, Sundberg H. Reasons for the caries decline: what do the experts believe. Eur J Oral Sci. 1996;104:416-22. 3. Marthaler T, Menghini G, Steiner M. Use of the Significant Caries Index in quantifying changes in caries in Switzerland from 1964 to 2000. Community Dent Oral Epidemiol. 2005;33:159-66. 4. Lucas SD, Portela MC, Mendonça LL. Variations in tooth decay rates among children 5 and 12 years old in Minas Gerais, Brazil. Cad Saude Publica. 2005;21:55-63. 5. Downer M. Caries prevalence in the United Kingdom. Int Dent J. 1994;44(4 Suppl 1):365-70. 6. Pitts NB, Boyles J, Nugent ZJ, Thomas N, Pine CM. The dental caries experience of 5-years-old children in England and Wales (2003/4) and Scotland (2002/3). Community Dent Health. 2005;22:46-56. 7. Cypriano S, Pecharki GD, Sousa MLR, Wada RS. Oral health of schoolchildren residing in areas with or without water fluoridation in Sorocaba, São Paulo State, Brazil. Cad Saude Publica. 2003;19:1063-71. 8. Hashim R, Thomson WM, Ayres KM, Lewsey JD, Awad M. Dental caries experience and use of dental services among preschool children in Ajman, UAE. Int J Paediatr Dent. 2006;16:257-62. 9. Creedon MI, O’Mullane DM. Factors affecting caries levels amongst 5-year-old children in Country Kerry, Ireland. Community Dent Health. 2001;18:72-8. 10. Li Y, Wang W. Predicting caries in permanent teeth from caries in primary teeth: an eight-year cohort study. J Dent Res. 2002;81:561-6. 11. Skeie MS, Raadal M, Strand GV, Espelid I. The relationship between caries in the primary dentition at 5 years of age and permanent dentition at 10 years of age – a longitudinal study. Int J Paediatr Dent. 2006;16:152-60. 100 Carvalho FS, Carvalho CAP, Bastos RS, Xavier A, Merlini SP, Bastos JRM Braz J Oral Sci. 8(2): 97-100 12. IBGE. Institute Brazilian of Geography and Statistics. Estimate of the population residing in Brazilians municipalities on July 1, 2008. [Internet]. [cited 2009 ago 25]. Available from: 13. Word Health Organization. Oral health surveys, basics methods. 4th ed. Geneve: WHO; 1997. 14. Nishi M, Stjernswärd J, Carlsson P, Bratthall D. Caries experience of some countries and areas expressed by the Significance Caries Index. Community Dent Oral Epidemiol. 2002;30:296-301. 15. Armfield JM, Spencer AJ, Slade GD. Changing inequalities in the distribution of caries associated with improving child oral health in Australia. J Public Health Dent. 2009;69(2):125-34. 16. Smith GE. Tooth decay in the developing world. N Z Med J. 1987;100:669-70. 17. Brazil. Health Ministry of Brazil. SB Brazil 2003 Project – Oral health conditions of the Brazilian population 2002-2003. Brasília, DF; 2004. 18. Martins RJ, Garbin CAS, Garbin AJI, Moimaz SAS, Saliba O. Declining caries rate in a municipality in northwestern São Paulo State, Brazil, 1998-2004. Cad Saude Publica. 2006;22:1035-41. 19. Cypriano S, Sousa MLR, Rihs LB, Wada RS. Oral health among preschool children in Brazil, 1999. Rev Saude Publica. 2003;37:247-53. 20. Hoffmann RHS, Cypriano S, Sousa MLR, Wada RS. Dental caries experience in children at public and private schools from a city with fluoridated water. Cad Saude Publica. 2004;20:522-8. 21. Leite ICG, Ribeiro RA. Dental caries in the primary dentition in public nursery school children in Juiz de Fora, Minas Gerais, Brazil. Cad Saude Publica. 2000;16:717-22. 22. Moura LFAD, Moura MS, Toledo OA. Dental caries in children that participated in a dental program providing mother and child care. J Appl Oral Sci. 2006;14:53-60. 23. Gomes PR, Costa SC, Cypriano S, Sousa MLR. Dental caries in Paulínia, São Paulo State, Brazil, and WHO goals for 2000 e 2010. Cad Saude Publica. 2004;20:866- 70. 24. Cardoso SV, Pereira SM, Tagliaferro EPS, Pereira AC, Meneghin MC. Oral health conditions in Campinas: a critical evaluation. Arquivos em Odontologia. 2004;40:341-52. 25. Ueda EMO, Dezan CC, Frossard WTG, Salomão F, Morita MC. Prevalence of dental caries in 3 and 5-year-old children living in a small brazilian city. J Appl Oral Sci. 2004;12:34-8. 26. Peres MA et al. Social and biological early life influences on severity of dental caries children aged 6 years. Community Dent Oral Epidemiol. 2005; 33:53-63. 27. Rihs LB, Sousa MLR, Cypriano S, Abdalla NM, Guidini DDN, Amgarten C. Dental caries activity in primary dentition, São Paulo, Brazil, 2004. Cad Saude Publica. 2007;23:593-600. 28. Tagliaferro EPS, Meneghim MC, Ambrosano GMB, Pereira AC, Sales-Peres SHC, Sales-Peres A, et al. Distribution and prevalence of dental caries in Bauru, Brazil, 1976-2006. Int Dent J. 2008;58:75-80. 29. Bratthall D. Introducing the Significant Caries Index together with a proposal for a new global oral health goal for 12-year-olds. Int Dent J. 2000;50: 378-84. 30. Sales-Peres SHC, Carvalho FS, Carvalho CAP, Bastos JRM, Lauris JRP. Polarization of dental caries in teen-agers in the Southwest of the state of São Paulo, Brazil. Cien Saude Colet. 2008;13(Suppl 2):2155-62. 31. Biazevic MGH, Rissoto RR, Michel-Crosato E, Mendes LA, Mendes MOA. Relationship between oral health and its impact on quality of life among adolescents. Braz Oral Res. 2008;22:36-42. 32. Cypriano S, Hoffmann RHS, Sousa MLR, Wada RS. Dental caries experience in 12- year-old schoolchildren in southeastern Brazil. J Appl Oral Sci. 2008;16:286-92.