舌向集中全口义齿应力分布的光弹性研究(下颌种植覆盖义齿加载)

Photoelastic analysis of stress distribution in complete dentures with lingualized occlusion(mandibular implant-retained overdenture)

目的研究舌向集中与解剖下颌种植覆盖义齿在正中、侧向及前伸应力加载时其支持组织的应力分布情况。方法应用三维光弹实验的方法,在CawoodⅤ类无牙颌模型双侧侧切牙至尖牙区域内各植入1枚种植体后制作环氧树脂光弹模型,分别进行正中、侧向及前伸垂直应力(1 kg)加载;应力冻结后,分析和比较舌向集中与解剖种植覆盖义齿周围支持组织的应力分布情况。结果侧向加载时,舌向集中种植覆盖义齿工作侧与平衡侧的应力差小于解剖种植覆盖义齿;侧向及前伸加载时,舌向集中种植覆盖义齿工作侧和平衡侧支持组织承受应力均小于解剖种植覆盖义齿。结论在使用2个种植体的球帽种植覆盖义齿时,舌向集中对种植体周围骨质有一定保护作用,且在侧向运动时更稳定,可作为种植全口覆盖义齿的首选人工牙。

Objective To investigate the stress distribution of supporting tissues in mandible implant-retained overdentures with lingualized occlusion and anatomic occlusion under the loads of centric,lateral and protrusive occlusion.MethodsPhotoelastic models of epoxy were fabricated according to the Cawood Ⅴ edentulous model with two implants in the area between lateral incisor and canine with three dimension photoelastic experiment method.One kilogram force was vertically applied in the centric,lateral and protrusive occlusion.After stress frozen,the stress distribution of supporting tissues in mandible implant-retained overdentures with lingualized occlusion and anatomic occlusion was evaluated.Results When using implant-retained overdentures,the force between working and balancing side of lingualized occlusion was smaller than that of anatomic occlusion,and the implant stress of lingualized occlusion was less than that of anatomic occlusion in both lateral and protrusive load.Conclusion When using two-implant-retained overdentures,lingualized occlusion could protect the bone around the implant,and was more stable in lateral movement,which might be considered first for complete implant-retained overdenture.