Division of Endodontics, Department of Advanced Oral Sciences and Therapeutics, University of Maryland, Baltimore, Maryland, USA.
Department of Oral & Maxillofacial Surgery, University of Maryland, Baltimore, Maryland, USA.
Int Endod J. 2021 May;54(5):793-801. doi: 10.1111/iej.13466.
To determine and compare the accuracy and efficiency of a dynamic navigation system (DNS) with a freehand (FH) technique when conducting root-end resection in a human cadaver model.
Forty roots in cadaver heads were included and divided into two groups: DNS (n = 20) and FH (n = 20). Cone beam computed tomography (CBCT) scans of all teeth were taken. The drilling path and depth were planned virtually to using the X-guide software (X-Nav Technologies, Lansdale, PA, USA). Osteotomy and root-end resection were done under navigation in the DNS group, and freehand under the dental operating microscope in the FH group. Post-operative CBCTs were taken. Linear deviations, angular deflection, time of operation and number of mishaps were compared with determine the accuracy and efficiency. Shapiro-Wilk, one-way ANOVA and Fisher exact tests were used (P < 0.05).
Linear deviations, angular deflection and operation time were significantly less in the DNS group (P < 0.05). The number of mishaps was not different between the two groups (P > 0.05). Subgroup analyses revealed that the distance of >5 mm from buccal cortical plate was significantly associated with lower accuracy, increased operation time and greater incidence of mishaps in the FH group (P < 0.05), but not in the DNS group.
The dynamic navigation system was more accurate and more efficient in root-end resection in a cadaver model than the freehand technique. The distance of the roots from the buccal cortical plate had a significant negative impact on the accuracy and efficacy of the root-end resection procedure when using the freehand technique. The dynamic navigation system has the potential to be a safe and reliable technological addition to endodontic microsurgery.
在人体尸体模型中，比较和评估动态导航系统（DNS）与徒手（FH）技术在进行根尖切除时的准确性和效率。
纳入 40 个头骨中的根，将其分为两组：DNS 组（n=20）和 FH 组（n=20）。对所有牙齿进行锥形束 CT（CBCT）扫描。使用 X-guide 软件（X-Nav Technologies，Lansdale，PA，USA）对虚拟钻孔路径和深度进行规划。DNS 组在导航下进行截骨和根尖切除，FH 组在牙科手术显微镜下徒手操作。在手术后进行 CBCT 扫描。比较线性偏差、角度偏差、手术时间和操作失误的数量，以确定准确性和效率。使用 Shapiro-Wilk、单因素方差分析和 Fisher 确切检验（P<0.05）。
DNS 组的线性偏差、角度偏差和手术时间明显较小（P<0.05）。两组的操作失误数量无差异（P>0.05）。亚组分析显示，FH 组中颊侧皮质板距离>5mm 与准确性较低、手术时间增加和操作失误发生率增加显著相关（P<0.05），但在 DNS 组中无此相关性。
在尸体模型中，与徒手技术相比，动态导航系统在根尖切除中更准确、更高效。当使用徒手技术时，根与颊侧皮质板的距离对根尖切除过程的准确性和效率有显著的负面影响。动态导航系统有可能成为牙髓显微手术中一种安全可靠的技术补充。
