Precision of a 3D Image-guided Implant Surgery and Digital Dental Prosthesis: A Preliminary Report

三度空間影像引導植體微創手術與數位義齒的精密度初步評估

董醒任(Shing-Zeng Dung)

《臺灣牙周病醫學會雜誌》 16卷2期 (2011/06) Pp. 127-140

摘要

二十一世紀植牙治療主要朝向簡單方便與減少侵犯性發展。由於患者期待縮短療程且越來越注重美觀，因此立即植牙立即施力的技術因運而生。術前審慎評估是植體成功的先決要件。目前單以臨床檢查無法有效評估植體部位骨頭的寬度與高度，因此需借助電腦斷層三度空間影像技術以增強術前診斷。螺旋斷層掃瞄技術提供影像重建的技術，提供術前評估的精確度。本計畫目的在體外評估本土與歐美三度空間影像軟體與三度空間數位義齒技術，並比較其引導之植牙手術與義齒製作精密度。以全口無牙上顎的樹脂模型，外以矽膠模擬口內情境。以電腦斷層掃瞄無牙上顎樹脂模型後以三度空間影像軟體處理，製作手術模板，選譯四個部位於複製模型上植入植體，並以三度空間數位義齒雕刻技術將假牙做好。植體與義齒裝戴之後將再以電腦斷層掃瞄。比對術前與術後電腦斷層影像，即可評估植入角度與義齒密合度的差異。本研究結果發現術前與術後植體部位與角度誤差皆在可容忍範圍內。術前規劃與手術真正的植入角度相差約2.2-4.7度。術前與術後植體頭部近遠心位置(lateral)誤差距離約0.29-1.16mm，根部位置約0.91-1.78mm。術前與術後植體頭部深度誤差距離約0.57-1.37mm，根部位置深度誤差距離約0.53-1.33mm。NobelGuide軟體無法提供術前與術後比較，但電腦掃瞄製作之假牙，於植體植入後可立即佩戴，且臨床與放射檢查貼合度良好。未來值得進一步長期臨床測試，以減少植入誤差，增加實用性。

關鍵字

3D電腦斷層 ； 影像導引手術 ； 牙科植體

並列摘要

The mainstream of implant therapy in the 21th century is simple, convenient, and minimum invasive. Patient's desire for shorter treatment periods and preservation of the esthetic appearance at all stages of the treatment has stimulated clinicians to explore immediate loading of dental implants. Thorough preoperative planning of implant treatment is the prerequisite for a successful treatment outcome. Clinical examination provided limited information on the width and height of jaw bone and may be improve by CT scan. Spiral CT enables the use of delicate software for accurate three-dimensional (3D) modeling and interactive 3d-based planning and simulation of implant surgery. The purpose of the study was to determine and to compare the precision of 3-D image-guided implant rehabilitation in vitro. Total or partial edentulous resin models were used in this project. A layer of silicon was used to mimic oral mucosa. Precision of 3D image-guided immediate fixed implant restoration was investigated using 4 implants in the edentulous maxilla. The fabrication of the custom- made drilling guide was based on three-dimensional computerized tomography. The installation of the implants was simulated pre-operatively using an adopted 3D-CT planning system. The pre-operative CT was then matched with post-operative ones in order to assess the deviation between the planned and installed implants. Data from the present study found that the differences between planned and final implant positions and axes were mostly acceptable. The match between the planned and achieved implant axes was within 2.2-4.7 degrees; average differences in distance between the planned and achieved positions at the implant shoulder were 0.29-1.16 mm, and at the implant apex, 0.91-1.78 mm. A greater distance between the planned and achieved positions at the implant apex than at the implant head was encountered in all implants. Average differences in depth (distance) between the planned and achieved positions at the implant shoulder were 0.57-1.37 mm, and at the implant apex, 0.53-1.33 mm. While NobelGuide(superscript TM) Software does not allow one to compare planned and actual implant positions and axes, temporary abutment and implant prosthesis were made and inserted immediately following implant placement. The fitness of the implant prosthesis was demonstrated clinically and radiographically. Further long-term clinical studies employing a greater number of patients should be performed to evaluate the real impact of the stereolithographic surgical guide on implant therapy.

並列關鍵字

3D computed tomography ； image-guided surgery ； dental implants