| Co-Investigator(Kenkyū-buntansha) |
KUMASAKA Hisao SCHOOL OF DENTISTRY PEDIATRIC DENTISTRY LECTURE, 歯学部, 講師 (10161697)
SHINNJI Hisaaki SCHOOL OF DENTISTRY PEDIATRIC DENTISTRY ASSISTANT PROFESSOR, 歯学部, 助教授 (00147993)
HAMADA Sakumitsu SCHOOL OF DENTISTRY PEDIATRIC DENTISTRY ASSISTANT, 歯学部, 助手 (60218534)
NISHIMURA Yasusi SCHOOL OF DENTISTRY PEDIATRIC DENTISTRY LECTURE, 歯学部, 講師 (20139562)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1999: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1998: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Research Abstract |
As the most highly mineralized of biological tissues dental enamel shows certain characteristics not found elsewhere in the body. Dental enamel and dentin, unlike other biological tissues, once formed do not metabolize or have a turnover rate. The original formed appetite mineral remains basically unchanged throughout life apart from changes occurring at its surface, in contact with oral tissues, where diffusion processed operate. Enamel reflects the trace element environment present in tissue fluids at the time of tooth development. Since there was no data on trace elements of lead, zinc and copper present in deciduous teeth on the Japanese we have made a study about the relationship between the environment and Japanese deciduous teeth.
1) Lead content in enamel and dentin of deciduous teeth study. It is the very widespread use of an organic Pb compound, in the form of a tetraalkyl derivative, as a gasoline (petrol) additive that has resulted in Pb as a major environmental pollutant. A
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s a result, tetraethyl lead in gasoline was restricted as an additive in Japan in 1975. The aim of the present study is to clarify the influence of air pollution on Japanese children, by monitoring trace element compared of two groups of children those born before and those born after the restriction in 1975.
2) Zinc and Copper content in enamel and dentin of deciduous teeth study. Zinc(Zn) and copper(Cu) are trace metal involved in many metabolic processes and enzyme system. So until 1983, the Japanese Ministry of Health and Welfare did not permit the addition of trace metals to commercial formula milks, and therefore the Zn and Cu content of the available preparations were lower than those of officially recommended values by the FAO/WHO, the committee on Nutrition of the American Academy of Pediatrics and the European Society for Pediatric Gastroenterology and Nutrition(ESPGN). The aim of the present study was to clarify the influence of low Zn and Cu levels in formula milks on the physical condition of Japanese children, by monitoring trace element comparing two groups of children, those born before and those born after the restriction was lifted.
RESULTS
1. Zn and Cu content of breast and formula milks :
Zn content in the formula milk was lower than that of the breast milk. Cu content in the formula milk was much lower than that of breast milk.
2. Zinc concentration in enamel
Breast fed groups remained highest and unchanged in Zinc before and after the addition. Mix and formula fed groups before the addition were lower than after the addition.
3. Zinc concentration in dentin
Maxillary breast fed group was higher than mix and formula fed groups, but the mandiburer breast fed Zinc content was similar in mix and formula feed. Formula fed groups after the addition were significantly higher than before the addition. Maxillary mix fed groups before the addition were similar to those after the addition, but the mandiburer groups after the addition were higher than those before the addition.
4. Copper concentration in enamel
Breast fed groups were higher than mix and formula fed groups, before and ager the addition remained highest and relatively unchanged. Mix and formula fed groups after the addition were higher than before the addition.
5. Copper concentration in dentin
Maxillary and mandiburer breast fed groups before and after the addition remained higher and relatively unchanged. Formula fed groups after the addition were higher than before the addition. Maxillary mix fed groups remained relatively unchanged before and after the addition, but the mandiburer mix fed groups after the addition were higher than those before the addition.
CONCLUSION
1.Significant correlation was observed between lead in enamel and dentin of deciduous teeth. This indicates that lead absorption in the body marked a decline after the restriction.
2. The Zn and Cu content of formula fed groups increased in enamel and dentin concentrations after the addition, indicating the influence of Ze and Cu addition to formula milk. However none of the final content match levels of Zn and Cu in breast milk. Less
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