Sønju Clasen A B, Ruyter I E
Department of Cariology, Faculty of Dentistry, University of Oslo, Norway.
Adv Dent Res. 1997 Nov;11(4):523-7. doi: 10.1177/08959374970110042101.
Caries progression has been shown to be faster in the deciduous than in the permanent dentition. Several factors influence caries progression. Among these are variations in the chemical composition of the two enamel types. The carbonate ion is known to occupy two different positions in the hydroxyapatite structure of the enamel, the hydroxide position (A) and the phosphate position (B). Carbonate may be of different chemical importance in the two lattice positions. In the present study, a quantitative determination of the carbonate in the two different positions (type A and type B) in deciduous and permanent enamel was performed by FTIR spectrometry. Calibration curves, made with synthesized hydroxyapatites with carbonates in either position, were used to determine the quantity of type A and type B carbonates in both enamel types. The deciduous enamel contained significantly more type A carbonate than permanent enamel. The total carbonate content (sum of type A and type B carbonates) was also significantly higher in deciduous than in permanent enamel. TG analysis of enamel samples confirmed the quantitative carbonate determinations by FTIR spectrometry. The difference in carbonate content between deciduous and permanent enamel may be one of several factors contributing to faster caries progression in deciduous teeth.
研究表明，乳牙龋病进展比恒牙更快。有几个因素会影响龋病进展。其中包括两种牙釉质化学成分的差异。已知碳酸根离子在牙釉质的羟基磷灰石结构中占据两个不同位置，即氢氧根位置（A）和磷酸根位置（B）。碳酸根在这两个晶格位置可能具有不同的化学重要性。在本研究中，通过傅里叶变换红外光谱法对乳牙和恒牙牙釉质中两个不同位置（A 型和 B 型）的碳酸根进行了定量测定。用在任一位置含有碳酸根的合成羟基磷灰石制作校准曲线，以确定两种牙釉质中 A 型和 B 型碳酸根的含量。乳牙牙釉质中 A 型碳酸根含量明显高于恒牙牙釉质。乳牙中碳酸根的总含量（A 型和 B 型碳酸根之和）也明显高于恒牙牙釉质。牙釉质样品的热重分析证实了傅里叶变换红外光谱法对碳酸根的定量测定结果。乳牙和恒牙牙釉质中碳酸根含量的差异可能是导致乳牙龋病进展更快的几个因素之一。
