Department of Oral and Maxillofacial Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan.
Anal Bioanal Chem. 2014 Feb;406(5):1355-63. doi: 10.1007/s00216-013-7075-y. Epub 2013 Jun 2.
Periodontal disease is a serious dental problem because it does not heal naturally and leads to tooth loss. In periodontal disease, inflammation at periodontal tissue is thought as predominant, and its effect against tooth itself remains unclear. In this study, we applied matrix-assisted laser desorption/ionization imaging mass spectrometry (IMS) to teeth for the first time. By comparing anatomical structure of tooth affected with periodontal disease with normal ones, we analyzed traces of the disease on tooth. We found signals characteristic of enamel, dentin, and dental pulp, respectively, in mass spectra obtained from normal teeth. Ion images reconstructed using these signals showed anatomical structures of the tooth clearly. Next, we performed IMS upon teeth of periodontal disease. Overall characteristic of the mass spectrum appeared similar to normal ones. However, ion images reconstructed using signals from the tooth of periodontal disease revealed loss of periodontal ligament visualized together with dental pulp in normal teeth. Moreover, ion image clearly depicted an accumulation of signal at m/z 496.3 at root surface. Such an accumulation that cannot be examined only from mass spectrum was revealed by utilization of IMS. Recent studies about inflammation revealed that the signal at m/z 496.3 reflects lyso-phosphatidylcholine (LPC). Infiltration of the signal is statistically significant, and its intensity profile exhibited the influence has reached deeply into the tooth. This suggests that influence of periodontal disease is not only inflammation of periodontal tissue but also infiltration of LPC to root surface, and therefore, anti-inflammatory treatment is required besides conventional treatments.
牙周病是一种严重的口腔问题，因为它不会自然愈合，导致牙齿脱落。在牙周病中，牙周组织的炎症被认为是主要原因，但其对牙齿本身的影响尚不清楚。在这项研究中，我们首次将基质辅助激光解吸/电离成像质谱（IMS）应用于牙齿。通过比较受牙周病影响的牙齿和正常牙齿的解剖结构，我们分析了牙齿上疾病的痕迹。我们从正常牙齿中获得的质谱中分别发现了牙釉质、牙本质和牙髓的特征信号。使用这些信号重建的离子图像清晰地显示了牙齿的解剖结构。接下来，我们对牙周病的牙齿进行了 IMS 分析。获得的总质谱特征与正常牙齿相似。然而，使用牙周病牙齿的信号重建的离子图像显示出牙周韧带的缺失，而正常牙齿中可见牙髓。此外，离子图像清晰地描绘了在根表面处 m/z 496.3 处的信号积累。这种仅从质谱中无法检测到的积累，通过 IMS 的应用得以揭示。最近关于炎症的研究表明，m/z 496.3 处的信号反映了溶血磷脂酰胆碱（LPC）。该信号的渗透具有统计学意义，其强度分布表明影响已经深入到牙齿内部。这表明牙周病的影响不仅是牙周组织的炎症，还有 LPC 渗透到根表面，因此除了常规治疗外，还需要进行抗炎治疗。
