Objective: To study stress distribution of edentulous alveolar bone supported with magnet retained mandibu-lar implant -supported overdentures. Method: Photoelastic models of epoxy were fabricated according to the standard mandibular edentulous model with two implants in the canine areas. The bio-functional complete dentures was made and connected with magnet attachments. Force was applied in conditions of centric , lateral and protrusive occlusion. After stress frozen, photoelastic model slices of different areas were made and stress fringes were observed. Result: In conditions of centric , lateral and protrusive occlusion, the maximum stress was observed on the alveolar bone around implants, more stress was observed on the molar areas. Less tress was observed on the incisive areas. In centric or protrusive occlusion. Stress was focused on the buccal alveolar bone of molar areas and the lingual alveolar bone of incisive areas. In lateral occlusion , stress was focused on the buccal alveolar ridge of work side and the lingual alveolar ridge of balance side. Conclusion: Stress of magnet retained mandibular implant-supported overdentures was distributed not only on the alveolar bone around the implants but also on the residual alveolar ridges, which can decrease the stress of alveolar bone around implant and increase the health of implant.%目的：研究磁性附着体下颌种植覆盖义齿在各种咬合状态时下颌牙槽骨的应力分布。方法：选取标准无牙颌模型，在双侧尖牙区植入种植体，连接磁性附着体，翻制下颌环氧树脂模型，制作生物功能性全口义齿，分别在正中、前伸、侧向咬合时加载应力，冻结切片，观测各牙位应力条纹。结果：磁性附着体下颌种植覆盖义齿在正中、侧向、前伸咬合应力加载时种植体周围牙槽骨应力值最大，余留牙槽嵴后牙区所受应力大于前牙区。正中(牙合)、前伸(牙合)磨牙区最大应力值出现于颊侧，切牙区最大应力值出现于舌侧。侧向(牙合)工作侧最大应力值出现于唇颊侧，平衡侧最大应力值出现于舌侧。结论：磁性附着体种植覆盖义齿各向咬合时，应力既分布到种植体，也分布到剩余牙槽嵴，可以明显降低种植体周围骨组织的受力，有利于种植体的健康。
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