利用電腦斷層影像引導鑽孔技術製作之人工植牙手術模板的臨床準確度試驗(３５支植體)

Abstract

中文摘要 緒論： 臨床植牙手術最主要的目標是把植體種植到植牙前便已經完善計畫的位置上，期望達到植體與其補綴物在功能、美觀、生物力學方面，都能有極佳的表現，而且病人在手術過程中，受到最小的手術傷害。所以，製作一個可靠的手術模板，應用於植牙手術中，將植體精確種植在顎骨上，是植體治療能否成功的關鍵性因素。 臨床上利用電腦斷層掃瞄影像及特殊影像分析軟體來進行植牙手術前規劃，在現今已經變得普遍，而且醫師在操作上，也更加容易。本實驗是利用先前已通過台大醫學院所做體外實驗之影像分析軟體與電腦輔助鑽孔系統，來製作臨床用手術模板，期望增加手術的準確度。

本實驗的目的是利用電腦輔助鑽孔技術（ImplantMax+DrillMax）所製作之手術模板於臨床病例上，並評估實際種植植體相對於術前規劃植體，其位置及軸向角度的偏差大小。

實驗材料及方法： 本實驗收集西元2007至2009年的植牙病患共24人，合計共植入35根植體（每名病患植體數1至3根）。每名病患都要完成手術前電腦斷層掃瞄影像檢查，及利用影像分析軟體，設計植體位置。照射電腦斷層掃瞄時，病患需戴上附有3顆陶瓷圓珠的影像定位器（此影像定位器是在三度空間中，可將電腦斷層掃瞄影像與診斷用石膏模型聯結的裝置）。

將規劃好植體位置的影像，利用電腦輔助鑽孔系統，將植體的位置從影像上轉移到石膏模型上，之後利用鑽好洞的石膏模型，製作手術模板。手術模板上嵌有各種直徑的植牙導引金屬套筒。在植牙手術中，便利用套筒將鑽頭及植體做精確的定位。等待植體完成骨整合後，利用影像重疊技術，計算實際植入植體與先前規劃植體間，位置與角度到底有多大偏差。 實驗結果： 實際植體與規劃植體間，平均角度偏差 6.08 ° (標準差1.44 °)，角度偏差範圍 2.36 °至 8.51 °，植體頸部平均偏差0.77mm(標準差0.19mm)，偏差範圍0.42至 1.26mm，植體尖端平均偏差1.12mm(標準差0.39mm)，偏差範圍0.22至1.73mm。

結論： 本臨床實驗的結果顯示，實際植體與規劃植體間的偏差大小及範圍，都與文獻回顧中利用電腦輔助植牙手術的其他系統，所產生的偏差大小及範圍相仿。偏差大小都在臨床醫師可接受之範圍。所以本實驗採用的電腦輔助鑽孔技術製作之手術模板，應用於臨床手術時，其準確度值得臨床醫師信賴。

Abstract Introduction: Clinically, the main goal of dental implantology is accurately positioning the dental implants completely coincided with the presurgical plan designed with an implant planning software. Accurate positioning the implants may result in improving functionality, esthetics, and biomechanical performance, as well as minimal complications. So, one of the most important factors for implant success is how to fabricate a reliable surgical template used in implant surgery. Using CT image and special software for implant planning becomes more popular and easier now. An implant planning software and a special computer-aided drilling technique to fabricate a reliable surgical template have been developed in National Taiwan University and tested in vitro. The purpose of this study was to evaluate the deviation of the axes and positions of the actual implant, placed with the aid of surgical guides fabricated with our CT image-guided drilling technique, from those of the pre-operative planned implant. Materials and Methods: Thirty-five implants of 24 patients (the number of implants placed in each patient : 1~3) were included and planned on the Cone-Beam CT reconstructed images during 2007 to 2009. Prior to CT scanning, three ceramic balls were attached to the radiographic stent as reference markers to link the reconstructed CT images to the patient’s stone cast. A special drilling device, controlled by a computer which transformed the coordination of planned implants on CT images to drilling parameters, was used to position the drilling guide tube on a surgical template on the stone cast. During implant surgery, all the implants were placed with the aid of guide tubes on surgical templates. After osseointegration of the implants, a special image-fusing technique was used to compare the locations and axes of the planned and placed implants. Results: Compared with the planned implants, the actual placed implants showed mean angular deviation of 6.08°±1.44°, and mean linear deviation of 0.77±0.19mm at the neck of implants and 1.12±0.39mm at the apex of implants. The ranges of angular deviation was 2.36 ° to 8.51 °. The ranges of linear deviation were 0.42 to 1.26mm at the neck of implants and 0.22 to 1.73 mm at the apex of implants. Conclusion: The data were comparable to the other studies investigating the accuracy of other surgical templates. Surgical templates fabricated with our CT image-guided drilling technique may represent a reliable means for CT guided implant surgery.