Sir John Walsh Research Institute, School of Dentistry, University of Otago, New Zealand.
Arch Oral Biol. 2011 May;56(5):512-9. doi: 10.1016/j.archoralbio.2010.11.009. Epub 2010 Dec 10.
The aim of this study was to investigate a possible role for demineralisation of the cervical region of human teeth in the development of non-carious cervical lesions (NCCLs).
Freshly extracted human premolars were demineralised and prepared for nanoindentation and scanning electron microscope (SEM) observation. After 1 day or 2 days demineralisation in a solution of pH 4.5, specimens were embedded, cut and polished to 1 μm diamond paste. Nanoindentation was done at the cementum-enamel junction (CEJ) region with an interval of 30 μm, to develop mechanical properties maps. After the indentation, SEM with back-scatter detector was employed to observe the degree of demineralisation at the CEJ.
After 1 day and 2 days demineralisation, the mechanical properties of enamel and dentine at the CEJ decreased by ∼50% and ∼90%, respectively. SEM images illustrate that artificial demineralisation generated typical demineralised zones in enamel near the CEJ. Moreover, 2 days demineralisation penetrated the sound enamel at the CEJ, and the dentine beneath was undermined.
One day and 2 days demineralisation reduced the mechanical properties of teeth at the CEJ significantly. Demineralised enamel and dentine with low mechanical properties are prone to wear and abrasion. The findings of the investigation indicate that acid typical of that produced by dental plaque may compromise the mechanical properties of enamel and dentine at the CEJ to the extent that they would be susceptible to tooth brush abrasion, producing NCCLs.
本研究旨在探讨人牙颈部脱矿是否在非龋性颈缘缺损（NCCLs）的发展中起作用。
将新鲜拔出的人前磨牙进行脱矿处理，并准备进行纳米压痕和扫描电子显微镜（SEM）观察。在 pH 值为 4.5 的溶液中脱矿 1 天或 2 天后，将标本包埋、切割并抛光至 1μm 金刚石膏。在牙骨质-釉质交界处（CEJ）进行纳米压痕，间隔 30μm，以绘制机械性能图谱。压痕后，采用背散射检测器的 SEM 观察 CEJ 处的脱矿程度。
脱矿 1 天和 2 天后，CEJ 处牙釉质和牙本质的机械性能分别下降了约 50%和 90%。SEM 图像表明，人工脱矿在 CEJ 附近的牙釉质中产生了典型的脱矿区。此外，2 天的脱矿穿透了 CEJ 处的健康牙釉质，下方的牙本质被侵蚀。
1 天和 2 天的脱矿显著降低了 CEJ 处牙齿的机械性能。机械性能较低的脱矿牙釉质和牙本质容易磨损。研究结果表明，类似于牙菌斑产生的酸可能会降低 CEJ 处牙釉质和牙本质的机械性能，使它们容易受到牙刷磨损，从而产生 NCCLs。
