种植体与天然牙联合支持固定桥的生物力学分析被引量：1

Biomechanics study on implant-natural tooth supported fixed partial dentures

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摘要背景:天然牙和种植体应力分布模式不尽相同,种植体-天然牙联合支持式固定桥的应力分布模式有待探讨。目的:对种植体、天然牙单冠以及种植体-天然牙联合支持固定桥进行垂直载荷,分析种植体骨界面与天然牙牙周的应力、应变分布情况。方法:选用2只成年雄性Beagle犬,全麻下拔除2只犬右侧下颌第一磨牙,3个月后拔牙区植入1颗Straumann 3.3 mm×10 mm常规颈种植体。3个月后麻醉处死,去处软组织后取完整下颌骨,一只犬行右侧下颌第四双根牙单冠和种植体单冠修复,另一只犬行联冠修复。下颌骨采用自凝塑料包埋后固定在加载装置上,在种植体和天然牙颈部相对应的颊舌侧皮质骨上贴应变片,并贴相应的电阻补偿片。在种植体、天然牙单冠以及种植体-天然牙固定桥基牙咬合面上分别采用40,60,80,120及160 N的力进行垂直加载。结果与结论:(1)种植体天-然牙联合修复后,当加载在种植体上时,其应变值要小于加载在种植体单冠上的应变值,部分负荷为天然牙承担;当加载在天然牙上时,其应变值要小于加载在天然牙单冠的应变值,部分负荷为种植体承担;(2)种植体-天然牙联合固定桥时,加载在天然牙基牙上时,应力由种植体和天然牙共同承担;而加载在种植体上基牙时,应力基本由种植体承担;(3)提示临床上种植体-天然牙联合固定桥修复是可行的。 BACKGROUND： The stress distribution is different between implants and natural teeth, and the biomechanicalcharacters of implant-natural tooth supported fixed partial dentures need to be explored.OBJECTIVE： To analyze the distributions of stress and strain on the implant interface and natural tooth ligaments byloading a vertical force to a single implant crown, natural tooth crown and a implant-natural tooth supported fixed partialdenture.METHODS： Two male healthy Beagle dogs were selected, and their right mandibular first molars were exacted undergeneral anesthesia. Three months later, a 3.3 mm×10 mm RN ITI implant was implanted into the defect region of eachdog. The dogs were killed under anesthesia after another 3 months to remove the mandible. One dog was restored by asingle implant and natural tooth crown, and the other was restored by the implant-natural tooth supported fixed partialdentures. The specimens were fixed to the load device after embedded with self caring acrylic resin, and the straingauges were pasted to the cortical bone around the implant and natural tooth neck. The vertical force was loaded to theimplant, natural tooth and fixed denture with 40, 60, 80,120, and 160 N.RESULTS AND CONCLUSION： When the force was loaded to the implant of combined denture, the implant stress ofcombined denture was less than that of the single implant repair, and partial force was loaded on natural teeth; when theforce was loaded to the natural tooth of combined denture, the stress to the natural tooth of combined denture was lessthan that of the single natural tooth repair. When the force was loaded to the natural tooth of combined denture, thestress was assumed by the whole prostheses. However, the stress was almost assumed by the implant when the forcewas loaded to the implant of combined denture. That is to say, it is feasible to use the implant-natural tooth supportedfixed partial dentures.