拔牙过程中常发生断根现象,此时往往需要使用根尖挺。此种根尖挺(如图左),具有挺刃尖锐、扁窄、容易插入断根与牙槽骨壁之间进行挺动的优点。由于一般断根常较牢固,挺动时往往需要施以较大的旋转力。而此种根尖挺的手柄外径较小(5毫米左右),故在挺动断根时手往往只是在柄 Tooth extraction often occurs during the root phenomenon, this time often need to use root tips. Such apex (such as the left), with a sharp blade, flat, easy to insert between the root of the alveolar bone and the advantages of stiffening. As the root is usually more solid stubble, Tingti often need to exert a greater rotational force. And such a sharp tip of the handle diameter is small (5 mm or so), so very often when the handle is severed