测量健康人釉质的羟基磷灰石密度和努氏硬度，并对其进行相关性分析。

Measurement of hydroxyapatite density and Knoop hardness in sound human enamel and a correlational analysis between them.

机构信息

State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.

出版信息

Arch Oral Biol. 2010 Feb;55(2):134-41. doi: 10.1016/j.archoralbio.2009.12.005. Epub 2010 Jan 12.

DOI:10.1016/j.archoralbio.2009.12.005

PMID:20064635

Abstract

OBJECTIVE

The aim of this study was to measure the hydroxyapatite (HAP) density and Knoop hardness (KHN) of enamel slabs and to analyse the relationship between them.

DESIGN

Twenty enamel slabs (10 lingual sides and 10 buccal sides) were prepared and scanned with micro-CT. Tomographic images of each slab from dental cusp to dentinoenamel junction (DEJ) were reconstructed. On these three-dimensional (3D) images, regions of interest (ROIs) were defined at an interval of 50 microm, and the HAP density for each ROI was calculated. Then the polished surfaces were indented from cusp to DEJ at intervals of 50 microm with a Knoop indenter. Finally, the data were analysed with one-way ANOVA, Student's t-test, and linear regression analysis.

RESULTS

The HAP density and KHN decreased from the dental cusp to DEJ. Both HAP density and KHN in the outer-layer enamel were significantly higher than those in the middle- or inner-layer enamel (P<0.05). The HAP density showed no significant difference between the buccal and lingual sides for enamel in the outer, middle and inner layers, respectively (P>0.05). The KHN in the outer-layer enamel of the lingual sides was significantly lower than that of the buccal sides (P<0.05); there was no significant difference between the lingual and buccal sides in the middle or inner layer. Linear regression analysis revealed a linear relationship between the mean KHN and the mean HAP density (r=0.87).

CONCLUSION

Both HAP density and KHN decrease simultaneously from dental cusp to DEJ, and the two properties are highly correlated.

摘要

目的

本研究旨在测量釉质块的羟基磷灰石（HAP）密度和努氏硬度（KHN），并分析两者之间的关系。

设计

制备 20 个釉质块（10 个舌侧和 10 个颊侧），并用微 CT 扫描。重建每个釉质块从牙尖到牙本质釉质界（DEJ）的断层图像。在这些三维（3D）图像上，每隔 50μm 定义感兴趣区域（ROI），并计算每个 ROI 的 HAP 密度。然后，用努氏压头从牙尖到 DEJ 以 50μm 的间隔在抛光表面进行压痕。最后，用单因素方差分析、学生 t 检验和线性回归分析对数据进行分析。

结果

HAP 密度和 KHN 从牙尖向 DEJ 逐渐降低。外层釉质的 HAP 密度和 KHN 均明显高于中层或内层釉质（P<0.05）。外层釉质的颊侧和舌侧之间的 HAP 密度在各层均无显著差异（P>0.05）。舌侧外层釉质的 KHN 明显低于颊侧（P<0.05）；中层和内层的舌侧和颊侧之间无显著差异。线性回归分析显示，平均 KHN 与平均 HAP 密度呈线性关系（r=0.87）。