Moustapha Ghassan, AlShwaimi Emad, Silwadi Munir, Ounsi Hani, Ferrari Marco, Salameh Ziad
Int J Comput Dent. 2019;22(1):45-53.
To evaluate the marginal adaptation and internal fit of milled fiber post and cores using different scanning methods.
Thirty typodont tooth models (Nissin) with pulp cavity were endodontically treated and prepared to receive 30 fabricated fiber post and cores. Three different methods of scanning were used (n = 10): an intraoral scanner (IOS) (Trios 3; 3Shape) to directly digitalize the post space (Group T) and a laboratory scanner to indirectly digitalize the resin pattern (Group RP) and the silicone impression (Group S) of the post space. All the specimens were examined using an optical microscope for the measurement of the vertical marginal discrepancy (VMD), and five in each group were scanned using microcomputed tomography (µCT) for the assessment of the VMD, the internal fit at the corner (IFC), post apex (PA), and at four horizontal cross-sections (CS1-4) inside the canal. All data were analyzed using mixed-design ANOVA, followed by pairwise testing to identify the differences (α = 0.05).
Statistical analysis revealed that Group T was associated with the smallest cement space compared with Group RP (P = 0.001) and Group S (P < 0.001) for VMD using µCT or direct microscopy (OM) (P < 0.001). Similarly, the cement space for Group T was smaller than that of Group S (P = 0.039) when measured at the IFC (µCT), and smaller than Group RP (P = 0.025) when measured at CS1-4 (µCT), with CS1 larger than CS3 (P = 0.015). There was no significant difference at PA (P = 0.271).
Better adaptation was achieved with a complete digital workflow. Scanning the resin pattern or the silicone impression introduced more variables in the digital process or milling of a one-piece fiber post and core.
评估使用不同扫描方法制作的纤维桩核的边缘适合性和内部适合性。
选取30个带有髓腔的典型牙模型（日进公司），进行根管治疗并预备以容纳30个制作好的纤维桩核。使用三种不同的扫描方法（n = 10）：口内扫描仪（IOS）（Trios 3；3Shape公司）直接对桩道空间进行数字化（T组），以及实验室扫描仪间接对桩道空间的树脂模型（RP组）和硅橡胶印模（S组）进行数字化。所有标本均使用光学显微镜检查以测量垂直边缘差异（VMD），每组选取5个标本使用微型计算机断层扫描（µCT）评估VMD、拐角处的内部适合性（IFC）、桩尖（PA）以及根管内四个水平横截面（CS1 - 4）处的内部适合性。所有数据采用混合设计方差分析进行分析，随后进行两两检验以确定差异（α = 0.05）。
统计分析显示，使用µCT或直接显微镜检查（OM）测量VMD时，与RP组（P = 0.001）和S组（P < 0.001）相比，T组的粘结剂空间最小（P < 0.001）。同样，在IFC处（µCT）测量时，T组的粘结剂空间小于S组（P = 0.039），在CS1 - 4处（µCT）测量时小于RP组（P = 0.025），其中CS1大于CS3（P = 0.015）。在PA处无显著差异（P = 0.271）。
完整的数字化工作流程可实现更好的适合性。扫描树脂模型或硅橡胶印模在数字化过程或一体式纤维桩核的铣削过程中引入了更多变量。
