Moustapha Ghassan, Azzam Khaled, AlShwaimi Emad, Silwadi Munir, Ferrari Marco, Salameh Ziad
Department of Prosthodontics, Faculty of Dental Medicine, Lebanese University, Hadath, Lebanon.
iDent Lab, Cluj-Napoca, Romania.
J Investig Clin Dent. 2019 Aug;10(3):e12413. doi: 10.1111/jicd.12413. Epub 2019 Apr 18.
The aim of the present study was to evaluate the marginal and internal fit of zirconium fixed partial denture using different impression techniques.
A Nissin Typodont model, including maxillary central incisor and canine with missing lateral incisor, was selected for the present study. Thirty zirconium frameworks were fabricated following three impression techniques (N = 10), conventional silicone impression (group C), scanned dental impression (group S), and Trios 3 (3Shape) intraoral scanner (group T). An extra-fine milling strategy was applied.
Group T had the smallest discrepancy compared to groups C (P = 0.006) and S (P = 0.052) at the marginal level, whereas it was larger at the incisal tip. Discrepancies in group T were smaller than group C (P = 0.004) when measured at the axial walls, and smaller than group S (P = 0.045) when measured at the chamfer area for the central teeth only. Samples in group T showed a greater percentage of equally extended restorations (52.5%), while other groups were mainly underextended (group C: 63.7%, group S: 68.8%).
Better adaptation was achieved with the intraoral scanner group, except at the incisal tip. Conventional and scanned impressions revealed a greater percentage of underextended restorations.
本研究旨在评估使用不同印模技术的锆合金固定局部义齿的边缘适合性和内部适合性。
本研究选用一个日进全牙列模型，包括上颌中切牙和尖牙，侧切牙缺失。按照三种印模技术（每组n = 10）制作30个锆合金框架，即传统硅橡胶印模（C组）、扫描式牙印模（S组）和Trios 3（3Shape）口腔内扫描仪（T组）。采用超精细研磨策略。
在边缘水平，T组与C组（P = 0.006）和S组（P = 0.052）相比差异最小，而在切端差异较大。在轴壁测量时，T组的差异小于C组（P = 0.004），仅在中央牙的肩台区域测量时，T组的差异小于S组（P = 0.045）。T组样本显示等延伸修复体的百分比更高（52.5%），而其他组主要是延伸不足（C组：63.7%，S组：68.8%）。
除切端外，口腔内扫描仪组获得了更好的适合性。传统印模和扫描印模显示延伸不足修复体的百分比更高。
