Cui Zhi, Wei Zhao, Du Minquan, Yan Ping, Jiang Han
The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Luoyu Road, Wuhan City, 237, China.
Department of Dentistry, Second Hospital of Baoding, 338 Dongfeng West Road, Baoding, China.
BMC Oral Health. 2018 Jun 25;18(1):115. doi: 10.1186/s12903-018-0573-8.
Comparison of the shaping ability of advanced nickel-titanium (Ni-Ti) instruments is of great interest to the field of endodontics. However, the models used to study canal preparation still lack uniformity, relevance to reality and complexity. The aim of this study was thus to compare the shaping abilities of the ProTaper Next (PN) and WaveOne (WO) Ni-Ti instruments in three-dimensional (3D)-printed teeth, which may overcome the present defects of most real teeth and model teeth including 3D S-shaped canals.
Six teeth and their corresponding 3D-printed replicas were prepared using the same kind of Ni-Ti instrument. The pre- and post-preparation volumes, surface areas and transportation of the canals were measured to compare the teeth with their replicas. Twenty 3D-printed teeth with S-shaped canals were used to support the preparation study. The S-shaped canals were then scanned to measure their volumes and surface areas. Next, the two kinds of instruments were used to prepare the 3D-printed canals (n = 10 per group). The volume and surface area of the canals, the transportation along the two curvatures and the percentage of unprepared surface area were measured. Micro-CT and VGstudio2.2 (VG2.2) software were used to perform scans and collect data throughout the research. The paired-samples T test and Kruskal-Wallis H test were used for statistical analysis.
There was no significant difference between the real canals and the printed ones post-preparation (P > .05). The printed S-shaped root canals had a unified shape, with a small standard deviation and range. The WO group had higher mean values for the volume and superficial area measurements compared with the PN group (P < .05). No differences in the untouched areas were found between the two systems (P > .05). PN caused less transportation at the apical curve than WO did (P < .05).
In conclusion, 3D-printed teeth are suitable for the study of Ni-Ti rotary instruments. Furthermore, the PN rotary system caused less transportation at the apical curve than the WO system did in complicated root canal procedures.
先进镍钛（Ni-Ti）器械的根管预备能力比较是牙髓病学领域非常关注的问题。然而，用于研究根管预备的模型仍缺乏统一性、与实际情况的相关性和复杂性。因此，本研究的目的是比较ProTaper Next（PN）和WaveOne（WO）镍钛器械在三维（3D）打印牙齿中的根管预备能力，这可能会克服大多数真实牙齿和模型牙齿（包括3D S形根管）目前存在的缺陷。
使用同一种镍钛器械对六颗牙齿及其对应的3D打印复制品进行预备。测量预备前后根管的体积、表面积和根管偏移情况，以比较牙齿及其复制品。使用20颗具有S形根管的3D打印牙齿来支持预备研究。然后对S形根管进行扫描以测量其体积和表面积。接下来，使用两种器械对3D打印根管进行预备（每组n = 10）。测量根管的体积和表面积、沿两个弯曲方向的根管偏移以及未预备表面积的百分比。在整个研究过程中，使用微型计算机断层扫描（Micro-CT）和VGstudio2.2（VG2.2）软件进行扫描并收集数据。采用配对样本T检验和Kruskal-Wallis H检验进行统计分析。
预备后真实根管和打印根管之间无显著差异（P > 0.05）。打印的S形根管形状统一，标准差和范围较小。与PN组相比，WO组在体积和表面积测量方面的平均值更高（P < 0.05）。两种系统在未触及区域方面未发现差异（P > 0.05）。PN在根尖弯曲处引起的根管偏移比WO少（P < 0.05）。
总之，3D打印牙齿适用于镍钛旋转器械的研究。此外，在复杂根管治疗过程中，PN旋转系统在根尖弯曲处引起的根管偏移比WO系统少。
