Abstract: Cementum consists of acellular cementum and cellular cementum. Under normal circumstances，there is a continuous deposition of cellular cementum in the apical 1/3 to compensate for crown abrasion. Clinically，we often find teeth with periapical infection by periapical film，and the cementum formation beyond the physiologic limits cause excessive cementum thickening，known as hypercementosis. The etiology of hypercementosis is still unclear，and may be related to periapical inflammation，mechanical stimulation，Paget′s disease and other factors. Hypercementosis affect the dentino-cemental junction，which brings challenges to the determination of working length in clinic. This paper will make an introduction to the etiology，characteristics，and strategy of hypercementosis to provide new ideas for clinical treatment of difficult periapical disease. 

Key words: hypercementosis, inflammation, apical periodontitis, cementum

摘要： 牙骨质由无细胞牙骨质和细胞牙骨质构成。在正常情况下，根尖1/3不断有细胞性牙骨质的沉积，以代偿牙冠的磨耗。临床中，我们常通过拍摄根尖片发现根尖周有病损的患牙，其牙根周围牙骨质形成异常增加，导致牙骨质过度增厚即牙骨质增生。牙骨质增生病因目前尚不明确，可能与根尖周炎症、机械刺激和骨的Paget病等相关。根尖周增生的牙骨质影响了牙本质-牙骨质界，在临床中对根管工作长度的确定带来了挑战。文章将从牙骨质增生的病因、特征及应对策略做一介绍，以期为临床治疗疑难根尖周病提供新思路。

关键词: 牙骨质增生, 感染, 根尖周炎, 牙骨质