The study on deciduous teeth enamel and dentin calcium content analyzed by Electron Probe X-ray Microanalysis

Objective To study the calcium content and distribution of deciduous teeth enamel and dentine and to discuss its relationship with caries.Methods Using Electron Probe X-ray Microanalysis(EPMA) microanalyzer to measure the calcium content at different depths on the vertical section of 40 mandibular deciduous central incisors and then grouping according to caries status of individual sample,each group is analyzed statistically respectively.Results The average value of total calcium content for the 40 mandibular deciduous central incisors is 37.13 ± 1.10(wt%),the calcium content of enamel is 38.31 ± 0.94(wt%),the calcium content of dentine is 36.66 ± 1.38(wt%);the calcium content of enamel subsurface 50μm and 100μm is higher than enamel subsurface 250μm;the calcium content of dentine under-enamelo-dentinal junction 50μm and 100μm is lower than respectively dentine under-enamelo-dentinal junction 450μm,500μm,550μm and 600μm.A statistics difference is not seen for the normal deciduous teeth's calcium content between caries-free group,low caries risk group and high caries risk group,and the normal deciduous teeth's calcium content has no correlation with decayed-filled tooth,decayed-filled surface and caries severity index.Conclusion The calcium distribution of normal deciduous teeth is non-homogeneous state.The calcium content of enamel showed a gradual decreasing trend from surface towards enamelo-dentinal junction;the calcium content of dentine showed a gradual increasing trend from enamelo-dentinal junction towards pulp cavity side.The calcium content of normal development deciduous teeth does not reflect the situation of individual caries as a single indicator.