Former Graduate Program Resident, Division of Restorative and Prosthetic Dentistry, Advanced Prosthodontics, College of Dentistry, The Ohio State University, Columbus, Ohio; Private Practice, Upper Arlington, Ohio.
Senior Research Associate, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
J Prosthet Dent. 2024 Nov;132(5):995-1004. doi: 10.1016/j.prosdent.2022.11.018. Epub 2023 Jan 21.
Digital light processing (DLP), continuous liquid interface printing (CLIP), and stereolithography (SLA) technologies enable 3-dimensional (3D) printing of surgical guides. However, how their accuracy compares and how accuracy may affect subsequent steps in guided surgery is unclear.
The purpose of this in vitro study was to investigate the fabrication and seating accuracy of surgical guides printed by using DLP, SLA, and CLIP technologies and evaluate the positional deviation of the osteotomy site and placed implant compared with the digital implant plan.
Twenty-one polyurethane models were divided into 3 groups and used to plan implants and design surgical guides. The guides were fabricated by using DLP, SLA, or CLIP 3D printers (n=7) and scanned, and the scan file was compared with the digital design file to analyze the fabrication accuracy at the intaglio and overall external surfaces using root mean square (RMS) values. The triple scan protocol was used to evaluate the seating accuracy of the guides on their respective models. Osteotomies were prepared on models by using the guides followed by a microcomputed tomography image of each osteotomy. The implants were placed through the guides, the scan bodies were tightened to implants, and the models were scanned to obtain the images of placed implant position. Osteotomy and placed implant images were used to calculate the entry point, apex, and long axis deviations from the planned implant position with a software program. A 2-way repeated-measures ANOVA of the RMS data was used to analyze printing and seating trueness, and homogeneity of variance analyses were used at each surface for precision. A 3-way repeated-measures ANOVA was used to analyze distance deviations over the stages (osteotomy and final implant) and locations studied, and a 2-way repeated-measures ANOVA was used for angular deviations. Homogeneity of variance analyses were performed for precision (α=.05).
The 3D printer type significantly affected the trueness of the guide at the intaglio surface (P<.001). SLA guides had the lowest mean RMS (59.04 μm) for intaglio surface, while CLIP had the highest mean RMS (117.14 μm). Guides from all 3D printers had low variability among measured deviations and therefore were similarly precise. The seating accuracy of SLA and DLP guides was not significantly different, but both had lower mean RMS values than CLIP (P=.003 for SLA, P=.014 for DLP). There were no significant interactions between the stage of surgery, the printer type, or the location of implant deviation (P=.734). Only the location of deviation (cervical versus apical) had a significant effect on distance deviations (P<.001). The printer type, stage of surgery, and their interaction did not significantly affect angular deviations (P=.41).
The 3D printing technology affected printing trueness. The intaglio surface trueness was higher with SLA and overall trueness was higher with the CLIP printer. The precision of all guides was similarly high. Guides from SLA and DLP printers had more accurate seating than those from CLIP. Higher deviations were observed at the apex; however, osteotomy and final implant position did not significantly differ from the digitally planned position.
数字光处理（DLP）、连续液体界面打印（CLIP）和立体光刻（SLA）技术可实现手术导板的 3 维（3D）打印。然而，其精度如何比较，以及精度如何影响引导手术的后续步骤尚不清楚。
本体外研究旨在调查使用 DLP、SLA 和 CLIP 技术打印的手术导板的制造和就位精度，并评估截骨部位和放置的种植体相对于数字化种植体计划的位置偏差。
将 21 个聚氨酯模型分为 3 组，用于规划种植体和设计手术导板。使用 DLP、SLA 或 CLIP 3D 打印机（n=7）制造导板并进行扫描，然后将扫描文件与数字设计文件进行比较，使用均方根（RMS）值分析凹面和整体外部表面的制造精度。使用三重扫描方案评估导板在各自模型上的就位精度。在模型上制备截骨，对每个截骨进行微计算机断层扫描成像。通过导板放置种植体，拧紧扫描体以固定种植体，然后扫描模型以获取放置的种植体位置的图像。使用软件程序计算种植体入口点、顶点和长轴与计划种植体位置的偏差。使用 2 因素重复测量方差分析 RMS 数据，分析打印和就位准确性，以及各表面的方差同质性分析精度。使用 3 因素重复测量方差分析研究阶段（截骨和最终种植体）和位置的距离偏差，并使用 2 因素重复测量方差分析分析角度偏差。精度的方差同质性分析（α=.05）。
3D 打印机类型显著影响凹面导板的准确性（P<.001）。SLA 导板的凹面 RMS 平均值最低（59.04 μm），而 CLIP 的 RMS 平均值最高（117.14 μm）。所有 3D 打印机的测量偏差之间的变异性均较低，因此精度相似。SLA 和 DLP 导板的就位精度无显著差异，但均低于 CLIP（SLA 为 P<.001，DLP 为 P=.014）。手术阶段、打印机类型和种植体位置之间无显著交互作用（P=.734）。只有手术部位（颈椎与根尖）对距离偏差有显著影响（P<.001）。打印机类型、手术阶段及其相互作用对角度偏差无显著影响（P=.41）。
3D 打印技术影响打印准确性。SLA 的凹面准确性更高，CLIP 打印机的整体准确性更高。所有导板的精度均相似。SLA 和 DLP 导板的就位准确性优于 CLIP。根尖处的偏差较大；然而，截骨和最终种植体位置与数字化计划位置无显著差异。
