本研究以結構振型探討牙科植體術後臨床骨缺損檢測課題，透過數值分析方法，找出植體/下顎骨局部模態植體振型及共振頻率，以利於評估骨缺損程度。研究分兩部份，第一部份為有限元素法分析，使用結合與摩擦兩種植體與下顎骨接觸條件，分別模擬臨床之植牙骨整合與以人造下顎骨進行實驗之情況，由模態分析獲得植體/下顎骨之自然頻率與振型，透過簡諧分析分別得到植體在頰舌側及近遠心側之響應。第二部份為聲能激振-位移響應實驗，以喇叭之聲能激振植體/下顎骨結構，並以非接觸式電容式位移計量測振動響應訊號，後續和Osstell III檢測儀量測結果作比較。 模擬結果顯示，結構產生植體局部模態振型時，檢測骨整合穩固度成效較明顯，而非接觸式聲能激振-位移響應實驗，受限於高頻響應位移小，以及位移計量測動態範圍、訊雜比低，對於高頻局部模態實驗效果不佳，僅能測得下顎骨低頻整體共振，不同缺損型態之共振頻率差異不大；另以Osstell III檢測儀可明確評估骨缺損程度。故上述模擬與實驗結果可證實需以植體局部模態之共振頻率進行骨缺損檢測。The aim of this study is to assess clinical bone defects between an implant and jaw bone after dental implantation by examining the mode shape of structures. Different severity of bone defects was evaluated through structure resonant frequencies and corresponding mode shapes of the implant and jaw bone by using numerical analysis and experimentation. This study consists of two parts. First, the assumption of two kinds of boundary conditions, bonding and rubbing, was applied to simulate osseointegration in the clinical dentistry and the in-vitro bone defect model, respectively, in finite element analysis. Natural frequencies and their mode shapes of the implant/jaw were computed by the modal analysis. During the harmonic analysis, the response displacement versus frequency of implant in the buccolingual and mesiodistal directions were defined. Secondly, the structural resonant frequencies were measured by the acoustic excitation-displacement response procedure, and then this result was compared with using the detection of Osstell mentor. The simulation results show that the structure local mode corresponding high-frequency resonance can be used to examining bone imperfection remarkably. Limited by extremely tiny response displacement, measuring dynamic range of the capacitive displacement sensor, the acoustic excitation-displacement response measurement can only acquire the structure global mode of the mandible corresponding to low-frequency resonance. In addition, Osstell mentor can assess bone defects effectively. Therefore, the above-mentioned simulations and experimental results prove that the local mode is promising to evaluate the defect severity for the osseointegration of dental implantation.
