在兩種骨密度的後下顎骨區比較動態導航與靜態導航植入傾斜植體的位置準確性

Abstract

中文摘要 實驗目的 计算机辅助种植体植入技术越来越受欢迎，因为根据修复驱动的外科计划准确定位牙种植体在种植体的长期存活和美学中起着重要作用。本研究使用X-Guide和Iris-100作为动态导航，以及3D完全引导的支架作为静态导航，对在两种不同骨密度（Sawbones®模拟的中等密度带有一层皮质硬骨（30 pcf，1 mm）和低密度无皮质骨（20 pcf，0 mm））条件下在下颌后部区域按照推荐的钻孔协议进行操作后的角度、平台和尖端偏差进行了比较。本研究的目的是确定在这些变量下，倾斜种植体植入的最准确协议。

實驗材料與方法 1. 实验模型的准备 使用患者的锥形束计算机断层扫描（CBCT）和下颌模型的实验室扫描来制作实验模型。本研究中，3D打印了一种完全无牙的主模型。在主模型的右下方（45号牙）有一个16x7x20mm³的切除区域，用于放置人工骨块。选择了两组人工骨块（Sawbones®），分别为30 pcf + 1mm皮质骨和20 pcf + 无皮质骨。每组有20块（n=120）。在每次测试前，固定人工骨块以确保稳定性。 2. 种植过程 使用3Shape Implant Studio在45号牙处以30度角计划种植体。设计并打印了一个由3个锚针支撑的骨支撑外科导板。此外，对于动态导航，数字数据被导出到其专有软件用于X-Guide和Iris-100。单一操作员按照制造商推荐的程序在人工骨块中钻孔并植入Nobel Parallel CC RP种植体（4.3x13mm）。 3. 种植体位置的准确性评估 将扫描体附着在种植体上，并用实验室扫描仪（3Shape E4）扫描。扫描数据与初始外科计划在计量软件（Geo magic Control X）中进行叠加。使用Kruskal-Wallis检验和Wilcoxon检验进行统计分析，显著性水平为P < 0.05。

實驗結果： 在按骨类型划分的小组中，Iris 100在尖端和角度偏差上有统计显著差异，其中无皮质+20pcf骨比1mm皮质+30pcf骨组显示出更准确的结果。此外，平台偏差上，支架在无皮质+20pcf骨组中比1mm皮质+30pcf骨组显示出更高的准确性。总的来说，按方法划分，角度偏差在支架和Iris 100之间没有显著差异，但它们都比X-Guide更准确。在尖端偏差上，支架比Iris 100更准确，而其他两组之间没有差异。最后，在平台偏差上，支架最准确，其次是X-Guide，再次是Iris 100，三组之间有统计差异。在精确度分析中也得到了类似的结果，支架最精确，其次是Iris 100，最后是X Guide，三组之间有显著差异。

結論： 使用静态导航和动态导航系统进行种植体植入的准确性在几个变量中得到了证明，一般来说支架组更准确，但所有导航系统的准确性都在可接受水平以上。另一方面，除了在Iris 100的角度和尖端偏差以及支架的平台偏差在较软的骨头中表现出更高的准确性外，骨类型差异对最终结果没有影响。还指出，三种不同方法的学习曲线陡峭，从研究开始到结束种植体准确性没有太大差异。

Abstract Objective Computer-assisted implant placement is becoming more popular because accurately positioning the dental implant according to a prosthetic-driven surgical plan plays an important role in the long-term survival and aesthetics of the implant. Using X-Guide and Iris-100 as dynamic navigation systems and 3D fully guided stents as static navigation, the angle, platform, and apex deviations were compared after following the recommended drilling protocol in the posterior mandibular area with two different bone densities simulated by Sawbones®: medium density with a layer of cortical hard bone (30 pcf, 1 mm) and low density with no cortical bone (20 pcf, 0 mm). The aim of this study was to determine the most accurate protocol for tilted dental implant placement within these variables. Materials and methods 1. Preparation of experimental models A patient’s cone beam computed tomography (CBCT) scan and the laboratory scan of the mandibular cast were used to fabricate the experimental model. One fully edentulous master model was 3D printed for this study. A resection area (16x7x20mm³) was created at the lower right (tooth 45) for the artificial bone blocks in the master model. Two groups of artificial bone blocks (Sawbones®), consisting of 30 pcf + 1 mm cortical bone and 20 pcf + no cortical bone, were selected. There were 20 blocks in each group (n=120). Before each test, the artificial bone block was fixed to ensure stability. 2. Implant procedure 3Shape Implant Studio was used to plan the implant at a 30-degree angulation at tooth 45. A bone-supported surgical guide, held by three anchor pins, was designed and printed. Additionally, for dynamic navigation, the digital data was exported to proprietary software for X-Guide and Iris-100. A single operator drilled and placed the Nobel Parallel CC RP implant (4.3x13mm) in the artificial bone blocks, following the manufacturer's recommended procedure. 3. Evaluation of the accuracy of implant position The scan body was attached to the implant and scanned with a lab scanner (3Shape E4). The scanned data was superimposed with the initial surgical plan using metrology software (Geomagic Control X). The Kruskal-Wallis test and Wilcoxon test were used for statistical analysis, with a significance level of P < 0.05. Results In the subdivision by bone type, there were statistically significant differences in the deviation of Iris 100 at the apex and angle. The no cortical + 20 pcf bone group showed more accurate results compared to the 1 mm cortical + 30 pcf bone group. Additionally, the stent at platform deviation showed higher accuracy in the no cortical + 20 pcf bone group compared to the 1 mm cortical + 30 pcf bone group. Overall, when divided by method, angle deviation showed no significant difference between the stent and Iris 100, but both were more accurate than X-Guide. For apex deviation, the stent was more accurate than Iris 100, with no difference between the other two groups. Lastly, for platform deviation, the stent was the most accurate, followed by X-Guide and then Iris 100, with statistical differences between the three groups. In the precision analysis, similar results were found, with the stent being the most precise, followed by Iris 100 and then X-Guide, showing significant differences between the three groups. Conclusion The accuracy of implant placement using static and dynamic navigation systems was demonstrated across several variables. Generally, the stent group was more accurate, but all navigation systems showed more than acceptable accuracy levels. On the other hand, bone type differences did not affect the final results, except for Iris 100 at angle and apex deviation, and the stent at platform deviation, which showed better accuracy with softer bone. It was also noted that despite the steep learning curve of the three different methods, there was no significant difference in implant accuracy from the beginning to the end of the study.