Department of Pediatric Dentistry, Dental School of Uberaba, University of Uberaba, Uberaba, Minas Gerais, Brazil.
Microsc Res Tech. 2010 May;73(5):572-7. doi: 10.1002/jemt.20796.
This study evaluated and compared in vitro the microstructure and mineral composition of permanent and deciduous teeth's dental enamel.
Sound third molars (n = 12) and second primary molars (n = 12) were selected and randomly assigned to the following groups, according to the analysis method performed (n = 4): Scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Energy dispersive X-ray spectrometer (EDS). Qualitative and quantitative comparisons of the dental enamel were done. The microscopic findings were analyzed statistically by a nonparametric test (Kruskal-Wallis). The measurements of the prisms number and thickness were done in SEM photomicrographs. The relative amounts of calcium (Ca) and phosphorus (P) were determined by EDS investigation. Chemical phases present in both types of teeth were observed by the XRD analysis.
The mean thickness measurements observed in the deciduous teeth enamel was 1.14 mm and in the permanent teeth enamel was 2.58 mm. The mean rod head diameter in deciduous teeth was statistically similar to that of permanent teeth enamel, and a slightly decrease from the outer enamel surface to the region next to the enamel-dentine junction was assessed. The numerical density of enamel rods was higher in the deciduous teeth, mainly near EDJ, that showed statistically significant difference. The percentage of Ca and P was higher in the permanent teeth enamel.
The primary enamel structure showed a lower level of Ca and P, thinner thickness and higher numerical density of rods.
本研究评估并比较了恒牙和乳牙牙釉质的微观结构和矿物质组成。
选择 12 颗第三磨牙（n=12）和 12 颗第二乳磨牙（n=12），并根据所进行的分析方法（n=4）随机分为以下组：扫描电子显微镜（SEM）、X 射线衍射（XRD）和能谱仪（EDS）。对牙釉质进行定性和定量比较。通过非参数检验（Kruskal-Wallis）对微观发现进行统计分析。SEM 照片中进行了棱柱体数量和厚度的测量。EDS 研究确定了钙（Ca）和磷（P）的相对含量。通过 XRD 分析观察了两种牙齿中存在的化学相。
乳牙牙釉质的平均厚度测量值为 1.14mm，恒牙牙釉质的平均厚度测量值为 2.58mm。乳牙牙釉质的杆头直径平均值在统计学上与恒牙牙釉质相似，并且从外釉面到釉牙骨质界附近的区域评估略有下降。乳牙的釉质杆数密度较高，特别是在釉牙骨质界附近，这具有统计学意义上的显著差异。恒牙牙釉质中的 Ca 和 P 百分比更高。
初级牙釉质结构的 Ca 和 P 含量较低，厚度较薄，杆数密度较高。
