The researchers demineralized the 180-million-year-old fossil of an ichthyosaur...and left behind soft, flexible tissues.

研究人员1.8前的鱼龙化石进行了去矿物处理，留下柔软且有韧性的组织。

That environment favors bacteria like mutans streptococci and Lactobacillus, which demineralize enamel and the dentin beneath it, and if untreated, it can eventually result in a cavitated caries lesion.

酸性境下的优势菌例如变形链球菌和乳酸杆菌，可以食牙釉及其下层的牙矿，如果不加以治疗，最终会形成空洞型龋齿。

So typically, dental plaque can form on the surface of teeth, b ut if the pH of the local environment around the tooth surface remains above about 5.5, enamel will not demineralize.

一般情况下，牙菌斑形成于牙齿表面，但当牙表面局部境的pH值持续高于5.5时，牙釉将不能矿化。