Abstract: Pulp necrosis in immature teeth，internal and external root resorption in permanent teeth，and over-instrumentation during the treatment will lead to the teeth with an open apex. Performing a proper endodontic treatment on teeth with open apex without weakening the resistance of tooth and reducing the stimulation of the irrigation fluid on the periapical tissue has always been a challenge. Appropriate mechanical preparation and intensive chemical preparation are the basic principles for dealing with this kind of teeth. In this paper，the root canal preparation method of teeth with open apex will be introduced.

Key words: open apex, root canal preparation, assistant irrigation technique

摘要： 年轻恒牙的牙髓坏死、成熟恒牙的牙根内外吸收及医源性根管超预备都将导致根尖狭窄区的丧失。在不削弱牙体组织抗力和降低冲洗液对根尖周组织刺激的前提下，如何对根尖孔敞开患牙进行根管预备一直是临床治疗的难点。适当的机械预备和强化的化学预备是治疗缺少根尖止点患牙的基本原则。文章对根尖孔敞开患牙的根管预备方法做一介绍。

关键词: 根尖孔敞开, 根管预备, 辅助冲洗技术