Abstract：
Pediatric endodontics has become popular due to advancements in cleaning, shaping and irrigation systems, resulting in faster and effective removal of infected pulp, saving time, and creating a pathogen-free environment. The patented rotary file system, Kedo-S, designed for primary teeth, introduced a single file generation for efficient pulp therapy. However, there are currently no studies assessing canal preparation in primary mandibular molars using nano-CT (computed Tomography). To evaluate the volumetric changes of two recently introduced pediatric rotary file systems in comparison with conventional hand file systems in primary mandibular molar using an ultra-high resolution nano-CT. This in-vitro study was performed in extracted primary mandibular molar based on certain inclusion and exclusion criteria. Samples were prepared and working length was determined before the pre-operative scan using a high resolution nano-CT device (SkyScan 2214, Bruker, Kontich, Belgium). A single well-experienced pediatric dentist prepared the canals using three file systems: Kedo-S plus, Kedo-SG blue and Hand K-files. A post-operative scan was performed similar to pre-operative scan. Image reconstruction was performed with NRecon software for 3D volumetric visualization and analysis of the root canals. Kedo-SG blue file systems had the highest mean difference in the canal volume (8.85%). Hand K-files had the least difference at (1.24%) of canal volume. Kedo-S plus file system had a mean canal volume difference (6.14%) which is closer to hand K-files. Rotary file systems resulted in a significant enlargement of canals compared to hand files.
摘要：
由于清洁方面的进步，儿科牙髓药已经变得流行，成型和灌溉系统，导致更快和有效地去除感染的纸浆，节省时间,创造一个无病原体的环境。专利的旋转文件系统，Kedo-S,专为乳牙设计，引入了一个单一的文件生成有效的牙髓治疗。然而,目前尚无使用纳米CT（计算机断层扫描）评估下颌磨牙的根管准备的研究。使用超高分辨率纳米CT评估两种最近引入的小儿旋转文件系统与传统的下颌磨牙手文件系统相比的体积变化。这项体外研究是根据某些纳入和排除标准在提取的原发性下颌磨牙中进行的。在手术前扫描之前，使用高分辨率纳米CT设备（SkyScan2214，Bruker，Kontich,比利时)。一位经验丰富的儿科牙医使用三个文件系统准备了运河：Kedo-Splus，Kedo-SG蓝色和手K文件。类似于术前扫描进行术后扫描。使用NRecon软件进行图像重建，以对根管进行3D体积可视化和分析。Kedo-SG蓝文件系统在运河体积中具有最高的平均差异(8.85%)。手动K档在运河容积（1.24％）处差异最小。Kedo-Splus文件系统的平均运河体积差异（6.14％）更接近手K文件。与手动文件相比，旋转文件系统导致运河显着扩大。
