Study on the Calcium Content of Enamel and Dentin in Deciduous Teeth.

Objective: To analyze the content of calcium in enamel and dentin of deciduous teeth and study their relationships with caries status. Methods: 37 children aged 5~7 years were enrolled in this study. 37 lower primary incisors were collected. They were divided into caries-free group (dft = 0, n =14) and caries group (dft0, n =23). Caries group were further divided into low-caries-risk group (0dft5, n =9) and high-caries-group (dft≥5, n =14). EPMA was used to analyze the Ca content in deciduous teeth. Ca content in enamel and dentin with different sides (mesial, distal, labial, lingual) and depths (outer layer, medium layer, inner layer) were investigated and compared. The relationship between Ca content and dft was also discussed. Results: 1) In enamel, Ca content is the lowest in lingual side ( P = 0.0001 ). Difference of Ca content in depths was only found in lingual side ( P =0.037), while the highest in outer layer and lowest in inner layer. 2) In dentin, there is no difference of Ca content among different positions ( P 0.05). Difference of Ca content in depths is found in labial, lingual and mesial sides except distal side. Totally in dentin, the Ca content is the highest in inner layer, then medium layer, and lowest in outer layer. 3) There is no difference of Ca content in enamel or dentin between caries-free group and caries-group. A relatively lower negative correlation is found between contents in Ca of mesial and labial enamel with dft ( r =-0.46, r =-0.40) and not in any other parts. Conclusions: Distribution of Ca content in enamel and dentin in deciduous teeth was investigated. There was no obvious relationship between Ca contents in enamel, dentin in deciduous teeth and caries status.