1 Introduction

1. Lead content in superficial deciduous enamel from children residing in areas with different probabilities of lead exposure and the correlation between caries experience and lead content Athayde PAA1, Almeida GRC2 *, Gerlach RF2 , Sousa FB1 1Depto. de Morfologia, CCS, Universidade Federal da Paraíba, João Pessoa (PB), Brasil; 2Depto. De Morfologia, Estomatologia Fisiologia, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto (SP), Brasil. UFPB c a b 1 Introduction Calcified tissue harbor lead.However, there are many practical problems that preclude the use of bone and dentine for wide screening for lead contamination. Enamel can be easily collected in mouth by an in vivo biopsy, and shows higher lead concentrations in teeth from subjects living in polluted environments in comparison to subjects living in non-polluted ones. The aim of this study was: to determine lead content in surface deciduous enamel from children studying in two Kindergartens, one located in a probably contaminated area (KG1) and another in a probably non-contaminated area with respect to environmental lead (KG2), and to test the effect of caries experience on lead content in surface deciduous enamel. 2 Methodology 24 and 22 children form KG1 and KG2, respectively, aged 4-8 yrs old, were undergone to enamel biopsies in upper incisors. Material from the enamel biopsies was used to measure lead by ICP-MS while phosphorus was measured colorimetrically to establish biopsy depth. Mann Whitney test was used to compare lead content between the two Kindergartens. Caries experience was determined using the decayed missing filled per tooth (dmft) index by one calibrated examiner (Kappa=0.81). 3 Results Children from KG1 presented higher mean dmft index compared to children from KG2 (p<0.01), but no correlation between dmft and lead content was found (p>0.05). Median lead levels were not statistically different between KG1 and KG2 considering either all biopsies depths (KG1=200.5 μg/g; KG2=163.4 μg/g; p=0.88) or only biopsies deeper than 3.17 µm (KG1=200.83; KG2=130.65; p=0.62). 4 Conclusion No correlation between dmft and lead content was found and the main difference between the two KGs was that the one located in a probably contaminated area presented the higher median lead content in surface enamel. 5 References 1) ALMEIDA, G. R. C.; SARAIVA, M.C.P.; BARBOSA, F.; KRUG, F.J.; CURY, J.A.; SOUSA, M.L.R.; BUZALAF, M.A.R.; GERLACH, R.F. Lead contents in the surface enamel of deciduous teeth sampled in vivo from children in uncontaminated and in lead-contaminated areas. Environ. Res., v.104, p.337-345, 2007. 2) ALMEIDA, G.R.C.; GUERRA, C.S.; TANUS-SANTOS, J.E.; BARBOSA Jr., F.; GERLACH, R.F. A plateau detected in lead accumulation in subsurface deciduous enamel from individuals exposed to lead may be useful to identify children and regions exposed to higher levels of lead. Environ. Res., v.107, p.264-270, 2008. 3) BRUDEVOLD, F.; AASENDEN, R.; SRINIVASIAN, B.N.; BAKHOS, Y. Lead in enamel and saliva, dental caries and the use of enamel biopsies for measuring past exposure to lead. J. Dent. Res., v.56, p.1165-1171, 1977.   4) BRUDEVOLD, F.; REDA, A.; AASENDEN, R.; BAKHOS, Y. Determination of trace elements in surface enamel of human teeth by a new biopsy procedure. Arch. Oral Biol., v.20, p.667, 1975. 5) GOMES, V.E.; SOUSA, M.L.R.; BARBOSA, F.; KRUG, F.J.; SARAIVA, M.C.P.; CURY, J.A.; GERLACH, R.F. In vivo studies on lead content of deciduous teeth superficial enamel of pre-school children. Sci. Total Environ., v.320, p.25, 2004. 6) GOMES, V.E.; WADA, R.S.; CURY, J.A.; SOUSA, M.L.R. Concentração de chumbo, defeitos de esmalte e cárie em dentes decíduos. Revista de Saúde Pública, São Paulo,v.38, n.5, out. 2004. Fig. 1 a, b, c. Enamel biopsy procedure Fig. 2. Plot of lead concentration versus biopsy depth Fig. 3. Plot of dmf-t versus lead concentration p= 0,88