口腔植體於高度落差無牙齒槽脊之短期療效評估

Abstract

研究目的 本研究針對高度落差（height discrepancy）齒槽脊進行口腔植體療效評估。主要目標為探討傾斜輪廓設計植體(sloped-configurated implant)對於減少植體螺紋裸露（thread exposure）之成效、次要目標為比較傾斜輪廓設計植體與標準植體，對於植體穩定度與鄰牙牙周狀態的影響。 研究材料與方法 本研究為單一中心隨機分派臨床試驗(single center randomized clinical trial)，所有納入的受試者皆在電腦斷層影像上缺牙區齒槽脊顯示頰舌側具有大於1毫米之高度落差，並隨機分派到實驗組及對照組。對照組使用標準植體，實驗組使用傾斜輪廓設計植體。所有植體尋醫療常規植入，若植入後有螺紋裸露均施予引導骨再生術輔助。 所有受試者都會在植體植入前進行電腦斷層影像分析及臨牙牙周臨床指標量測、於植體植入後進行螺紋裸露與植體穩定度量測，並於植體植入後六個月進行螺紋裸露、植體穩定度與牙周臨床指標的量測。 結果 總計有19位受試者及30支口腔植體（17支標準植體與13支傾斜輪廓設計植體）納入研究，對照組的術前兩組間齒槽脊高度落差無顯著差異（對照組1.84±0.73毫米，實驗組1.85±0.58毫米）；植入之螺紋裸露量對照組顯著大於實驗組（1.59±1.23 versus 0.62±0.96毫米），此時螺紋裸露發生率分別為70.59%與38.46%；植入後六個月，對照組與實驗組之螺紋裸露量為0.35±0.49毫米與0.08±0.28毫米，兩組間無顯著差異，螺紋裸露發生率則為35.29%與7.69%。 植體穩定度於兩組植入時和植入後六個月均無顯著差異。實驗組術前臨牙牙齦發炎指數顯著高於對照組、六個月改變量亦顯著優於對照組，其餘臨牙臨床發炎指標無論術前或術後六個月兩組均無顯著差異。 結論 於高度落差齒槽脊進行植牙手術，選擇傾斜輪廓設計植體可提供良好骨整合效果，相較於標準植體，會減少螺紋裸露的發生率及裸露程度，對於植入後的維護亦有助益。

Research Goals This study was designed for evaluating dental implant placement on the edentulous ridge with height discrepancy. The primary goal was to validate that the implant thread exposure on the ridge with height discrepancy was reduced by installing sloped-configured implants. The secondary goal was to evaluate the influence of implant stability and periodontal clinical parameters of adjacent teeth after sloped-configured implant installation. Material and Methods This single center randomized clinical trial recruited patients with prospective implant sites which presented ≥1 mm buccal-lingual ridge height discrepancy from the cone beam computed tomography (CBCT). Sites were randomly assigned to receive either received standard implants (control group) or sloped-configured implants (test group). Adjunctive guided bone regeneration was performed to ensure the full coverage of implant threads. CBCT and periodontal clinical parameters assessments were performed at baseline. Thread exposure and implant stability quotient (ISQ) were measured immediately after implant installation. Thread exposure, ISQ and periodontal clinical parameters were assessed 6 months after implant placement. Results 19 patients with 30 dental implants were included (17 standard implants and 13 sloped-configured implants). At baseline, the ridge height discrepancies were 1.84±0.73 mm and 1.85±0.58 mm in the control and test groups. After implant installation, thread exposure was significantly reduced in the test group (0.62±0.96 mm) relative to control (1.59±1.23 mm; p<0.05), and the prevalence of thread exposure was 70.59% and 38.46% of the control and test groups. After 6 months, thread exposure was 0.35±0.49 mm and 0.08±0.28 mm in the control and test groups, and the prevalence of thread exposure was 35.29% and 7.69% respectively. The ISQ value showed no significant difference between two groups at implant placement and 6 months after implant placement. The gingival index at baseline was significantly higher in the test group relative to that in control. All the other periodontal clinical parameters showed no significant difference between two groups at baseline and 6 months after implant placement. Conclusions Compared with the standard implants, sloped-configurated implants could reduce both the amount and prevalence of thread exposure for the cases with ridge discrepancy.