Oh Kyung Chul, Kim Jee-Hwan, Woo Chang-Woo, Moon Hong Seok
Department of Prosthodontics, Yonsei University College of Dentistry, Seoul 03722, Korea.
Central Dental Laboratory, Yonsei University Dental Hospital, Seoul 03722, Korea.
J Clin Med. 2019 Apr 11;8(4):490. doi: 10.3390/jcm8040490.
Limited evidence is available comparing the differences between pre-operative and post-operative 3D implant positions from the viewpoint of prosthetics. We aimed to investigate the differences between preplanned positions of virtual provisional restorations and their actual positions following fully guided single-implant placement. Ten maxillary typodonts with missing right central incisors were imaged using cone-beam computed tomography, and digital impressions were obtained using an intraoral scanner. These data were imported into implant-planning software, following which the provisional restorations were designed. After data superimposition, an appropriate implant position was determined, and a computer-assisted implant surgical guide was designed for each typodont. Orders generated from the implant-planning software were imported into relevant computer-aided design software to design the custom abutments. The abutments, provisional restorations, and surgical guides were fabricated, and each restoration was cemented to the corresponding abutments, generating a screw-type immediate provisional restoration. The implants were placed using the surgical guides, and the screw-type provisional restorations were engaged to the implants. The typodonts were then rescanned using the intraoral scanner. The restorations designed at the treatment planning stage were compared with those in the post-operative scan using metrology software. The angular deviation around the central axis of the implant was measured, and the differences in the crown position were converted to root mean square (RMS) values. The post-operative provisional restorations exhibited an absolute angular deviation of 6.94 ± 5.78° and an RMS value of 85.8 ± 20.2 µm when compared with their positions in the pre-operative stage. Within the limitations of the present in vitro study, the results highlight the potential application of customized prefabricated immediate provisional restorations after single-implant placement.
从修复学角度比较术前和术后3D种植体位置差异的证据有限。我们旨在研究虚拟临时修复体的预设计位置与完全引导下单颗种植体植入后其实际位置之间的差异。使用锥形束计算机断层扫描对上颌右中切牙缺失的10个牙模进行成像，并使用口腔内扫描仪获取数字印模。将这些数据导入种植体规划软件，然后设计临时修复体。数据叠加后，确定合适的种植体位置，并为每个牙模设计计算机辅助种植手术导板。将种植体规划软件生成的指令导入相关计算机辅助设计软件，以设计定制基台。制作基台、临时修复体和手术导板，将每个修复体粘结到相应的基台上，制作出螺丝型即刻临时修复体。使用手术导板植入种植体，并将螺丝型临时修复体安装到种植体上。然后使用口腔内扫描仪对牙模进行再次扫描。使用计量软件将治疗计划阶段设计的修复体与术后扫描的修复体进行比较。测量种植体中心轴周围的角度偏差，并将牙冠位置的差异转换为均方根（RMS）值。与术前阶段相比，术后临时修复体的绝对角度偏差为6.94±5.78°，RMS值为85.8±20.2µm。在本体外研究的局限性内，结果突出了定制预制即刻临时修复体在单颗种植体植入后的潜在应用。
