A Study of Development and Lesion of Dental Hard Tissue: Quantitative Analysis of Trace Elements (Cd, Zn, Pb and Cu) in Different Geological Areas of Japan

Trace elements (Cd, Zn, Pb and Cu) levels were determined in lower deciduous incisors which were collected from four areas (Sapporo, Yokosuka, Nagano and Kitakyushu) in Japan. Samples were divided into enamel and dentin, and dissolved with nitric and dried at 80°C. Each element was separated chomatagraphically using an aceton-HCL gradient solution with a cation exchange resin and then analyzed by atomic absorption spectrophotometry. >The results were as follows: >1. Ca, P, Ca/P ratio levels showed no significant differences among four areas. >2. In the enamel, >(1) Cd levels of each area were 0.593μg/g (Yokosuka)>0.315μg/g(Sapporo)>0.261μg/g (Nagano)>0.222μg/g (Kitakyushu). >(2) Zn levels of each area were 174.912μg/g (Nagano)>157.473μg/g (Yokosuka)>150.971μg/g (Kitakyushu)>128.980μg/g (Sapporo). >(3) Pb levels of each area were 8.412μg/g (Kitakyushu)>7.925μg/g (Yokosuka)>5.426μg/g(Sapporo)>4.285μg/g(Nagano). >(4) Cu levels of each area were 9.276μg/g (Kitakyushu)>6.928μg/g (Nagano)>6.178μg/g (Yokosuka)>4.389μg/g (Sapporo). >3. In the dentin, >(1) Cd levels of each area were 0.214μg/g (Sapporo)>0.184μg/g (Kitakyushu)>0.145μg/g (Nagano)>0.119μg/g (Yokosuka). >(2) Zn levels of each area were 124.152μg/g (Yokosuka)>112.242μg/g (Nagano)>111.952μg/g (Sapporo)>111.456μg/g (Kitakyushu). >(3) Pb levels of each area were 3.584μg/g (Kitakyushu)>3.019μg/g(Yokosuka)>1.819μg/g (Sapporo)>1.523μg/g (Nagano). >(4) Cu levels of each area were 3.734μg/g (Kitakyushu)>2.221μg/g (Nagano)>2.098μg/g (Yokosuka)>1.664μg/g (Sapporo). Therefore, the results suggest that the trace elements levels in deciduous teeth depended on the environmental condition of each area and the deciduous teeth could be a useful material as an environmental contamination indicator.