Joda Tim, Brägger Urs
Section for Digital Reconstructive Technology & Implant Dentistry [DiRecT+ID], School of Dental Medicine, University of Bern, Bern, Switzerland.
Department of Reconstructive Dentistry & Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
Clin Oral Implants Res. 2016 Nov;27(11):1401-1406. doi: 10.1111/clr.12753. Epub 2016 Jan 6.
The aim of the randomized controlled trial was to analyze time-efficiency of a treatment with implant crowns made of monolithic lithium disilicate (LS2) plus titanium base vs. porcelain fuse to zirconium dioxide (ZrO ) in a digital workflow.
Twenty study participants were included for single-tooth replacement in premolar and molar sites. Baseline was the start of the prosthetic treatment. All patients received transocclusal screw-retained implant reconstructions on a soft tissue level-type implant. The 3D implant position was captured with intraoral optical scanning (IOS). After randomization, ten patients were restored with CAD-/CAM-produced monolithic LS2-crowns bonded to prefabricated titanium abutments without any physical models (test), and ten patients with CAD-/CAM-fabricated ZrO -suprastructures and hand-layered ceramic veneering with milled master models (control). Every single clinical and laboratory work step was timed in minutes and then analyzed for time-efficiency with Wilcoxon Rank Sum Tests. Direct costs were assessed for laboratory fees for first line production in Swiss Francs (CHF).
Two clinical appointments were necessary for IOS and seating of all implant crowns. The mean total production time, as the sum of clinical plus laboratory work steps, was significantly different, resulting in 75.3 min (SD ± 2.1) for test and 156.6 min (SD ± 4.6) for control [P = 0.0001]. Analysis for clinical treatment sessions showed a significantly shorter mean chair time for the complete digital workflow of 20.8 min (SD ± 0.3) compared to 24.1 min (SD ± 1.1) [P = 0.001]. Even more obvious were the results for the mean laboratory work time with a significant reduction of 54.5 min (SD ± 4.9) vs. 132.5 min (SD ± 8.7), respectively [P = 0.0001].
The test workflow was more time-efficient than the controls for implant-supported crowns; notably, laboratory fabrication steps could be effectively shortened with the digital process of monolithic LS2 plus titanium base resulting in more than 30% reduced overall treatment costs.
这项随机对照试验的目的是分析在数字化工作流程中，使用整体式二硅酸锂（LS2）加钛基制作的种植体冠与氧化锆烤瓷熔附冠（ZrO）进行治疗的时间效率。
纳入20名研究参与者，用于前磨牙和磨牙部位的单颗牙替换。基线为修复治疗开始时。所有患者均在软组织水平型种植体上接受经咬合面螺丝固位的种植体重建。通过口腔内光学扫描（IOS）获取种植体的三维位置。随机分组后，10名患者采用计算机辅助设计/计算机辅助制造（CAD/CAM）制作的整体式LS2冠粘结到预制钛基台上，无需任何实体模型（试验组），另外10名患者采用CAD/CAM制作的ZrO上部结构并结合手工分层陶瓷饰面，使用研磨的母模（对照组）。对每个临床和实验室工作步骤进行分钟计时，然后使用Wilcoxon秩和检验分析时间效率。以瑞士法郎（CHF）评估一线生产的实验室费用直接成本。
IOS和所有种植体冠就位需要两次临床预约。作为临床加实验室工作步骤总和的平均总生产时间有显著差异，试验组为75.3分钟（标准差±2.1），对照组为156.6分钟（标准差±4.6）[P = 0.0001]。对临床治疗阶段的分析表明，与24.1分钟（标准差±1.1）相比，完整数字化工作流程的平均椅旁时间显著缩短，为20.8分钟（标准差±0.3）[P = 0.001]。平均实验室工作时间的结果更为明显，试验组显著减少至54.5分钟（标准差±4.9），而对照组为132.5分钟（标准差±8.7）[P = 0.0001]。
对于种植体支持的牙冠，试验工作流程比对照组更具时间效率；值得注意的是，通过整体式LS2加钛基的数字化工艺可有效缩短实验室制作步骤，使总体治疗成本降低超过30%。
