The remaining dentin thickness investigation of the attempt to remove broken instrument from mesiobuccal canals of maxillary first molars with virtual simulation technique.
The remaining dentin thickness investigation of the attempt to remove broken instrument from mesiobuccal canals of maxillary first molars with virtual simulation technique.
复制标题
虚拟模拟技术拔除上颌第一磨牙近颊管破损器械的剩余牙本质厚度研究
DOI：
10.1186/s12903-015-0075-x
复制
发表时间：
2015-07-28
期刊：
影响因子：
2.9
通讯作者：
Gao Y
中科院分区：
文献类型：
--
作者：
Yang Q;Cheung GS;Shen Y;Huang D;Zhou X;Gao Y
目的探讨虚拟仿真模型中模拟上颌第一磨牙近颊根管折断器械取出后，平行法和视差法根尖片最小剩余牙本质厚度（RDT）的差异。方法对36颗上颌第一磨牙进行micro-CT扫描，并重建三维模型。在软件中的MB通道内创建了一个虚拟的仪器片段。在3D和2D数据集中模拟取出断裂手术工具。然后，将所有样本的模型提交给2D和3D测量，以获得每个样本的最低（RDT）值。采用双因素方差分析比较平行和视差摄影技术与3D-RDT值之间的差异。组内相关系数（ICC）被用来评估的RDT测量的一致性之间的两个根尖X线片和技术和3D analysis.ResultsThere是从平行技术和3D-RDT获得的RDT值之间的显着差异。3D-RDT与视差（成角）技术获得的RDT之间无差异。平行法与三维测量法的RDT值的ICC均小于0.75。成角X线片和3D技术之间的ICC接近0.75。视差技术的最佳水平角度约为21°.ConclusionsThe虚拟模拟技术可以提供有价值的洞察力的利益/风险分析之前，删除一个破碎的仪器。平行线法高估了上颌第一磨牙近颊根管中残留牙本质的实际厚度，而平行线法在投照角度约为21°时能更接近实际厚度。
BackgroundTo investigate differences in the estimated minimum remaining dentin thickness (RDT) between periapical radiographs using the paralleling and parallax technique, after simulated removal of broken instrument from the mesiobuccal (MB) canal of maxillary first molar in virtual simulation model. The 3D measurement was taken as the standard for comparison.MethodsThirty-six maxillary first molars were scanned by micro-CT and reconstructed as 3-dimensional (3D) model. A virtual fragment of an instrument was created within the MB canal in software. Removal of the broken instrument was simulated in both the 3D and 2D dataset. Then, the models of all specimens were submitted to 2D and 3D measurements for the lowest (RDT) value in each. Differences in the values between the paralleling and parallax radiographic technique and the 3D-RDT value were analyzed with two-way Analysis of Variance. The Intra-class Correlation Coefficient (ICC) was used to assess consistency of the RDT measurements between the two periapical radiographic and techniques and 3D analysis.ResultsThere was significant difference between RDT value obtained from the paralleling technique and 3D-RDT. There were no differences between RDT obtained from parallax (angled) technique and 3D-RDT. The ICC of RDT values between paralleling technique and 3D measurement were lower than 0.75. ICC between angled radiographs and 3D technique was close to 0.75. The optimal horizontal angle for the parallax technique was about 21°.ConclusionsThe virtual simulation technique can provide valuable insight into the benefit/risk analysis before removal of a broken instrument. Parallel radiographs overestimate the actual remain dentin thickness in mesiobuccal canals of maxillary first molars, whereas the parallel technique would give a closer estimate to the actual thickness at a projection angle of about 21°.