Farah R A, Drummond B K, Swain M V, Williams S
Department of Oral Sciences, Faculty of Dentistry, University of Otago, New Zealand.
J Dent. 2008 Nov;36(11):915-21. doi: 10.1016/j.jdent.2008.07.012. Epub 2008 Sep 10.
To study the relation between the mechanical properties of hypomineralised enamel, and its laser fluorescence (LF).
Five extracted teeth with molar-incisor hypomineralisation (MIH) were sectioned longitudinally through the defects and polished to prepare the hypomineralised enamel for testing. Hardness (H) and elastic modulus (E) of enamel were measured using nanoindentation. Measurement recording started from the cervicoenamel junction and proceeded occlusally in increments of 200 microm. Laser fluorescence readings were taken along the same line and at the same sites using a DIAGNOdent pen.
H, E, and LF readings from cervical enamel were within the expected range for normal sound enamel. After log transformation of the H and E measurements to allow for linear correlation analysis, there was a significant and moderately strong inverse correlation between LF and H or E samples (r (between specimens)=0.59, r (between specimens)=0.39, respectively; p<0.001).
This study shows that, in the absence of dental caries, increased DIAGNOdent readings can indicate enamel hypomineralisation. While the increased LF readings in carious enamel are thought to be related to the presence of caries bacterial metabolites, the increased readings in hypomineralised enamel may be related to proteins in the hypomineralised enamel and/or light scattering by the inhomogeneous enamel.
研究矿化不足釉质的力学性能与其激光荧光（LF）之间的关系。
选取五颗患有磨牙-切牙矿化不足（MIH）的离体牙，沿缺损处纵向切开并打磨，制备矿化不足的釉质用于测试。使用纳米压痕法测量釉质的硬度（H）和弹性模量（E）。测量记录从釉牙骨质界开始，向咬合面以200微米的增量进行。使用DIAGNOdent笔在同一条线上的相同部位读取激光荧光读数。
颈部釉质的H、E和LF读数在正常健康釉质的预期范围内。对H和E测量值进行对数转换以进行线性相关分析后，LF与H或E样本之间存在显著且中等强度的负相关（样本间r分别为0.59和0.39；p<0.001）。
本研究表明，在无龋齿的情况下，DIAGNOdent读数增加可表明釉质矿化不足。虽然龋坏釉质中LF读数增加被认为与龋菌代谢产物的存在有关，但矿化不足釉质中读数增加可能与矿化不足釉质中的蛋白质和/或不均匀釉质的光散射有关。
