3D 打印与铣削整体氧化锆冠的精度和准确性：一项体外研究。

Trueness and precision of 3D-printed versus milled monolithic zirconia crowns: An in vitro study.

机构信息

Department of Oral Surgery, University of Szeged, Szeged, Hungary.

Department of Oral and Maxillofacial Sciences, Sapienza University, Rome, Italy.

出版信息

J Dent. 2021 Oct;113:103792. doi: 10.1016/j.jdent.2021.103792. Epub 2021 Sep 2.

DOI:10.1016/j.jdent.2021.103792

PMID:34481929

Abstract

PURPOSE

To compare the trueness and precision of 3D-printed versus milled monolithic zirconia crowns (MZCs).

METHODS

A model of a maxilla with a prepared premolar was scanned with an industrial scanner (ATOSQ®, Gom) and an MZC was designed in computer-assisted-design (CAD) software (DentalCad®, Exocad). From that standard tessellation language (STL) file, 10 MZCs (test) were 3D-printed with a Lithography-based Ceramic Manufacturing (LCM) printer (CerafabS65®, Lithoz) and 10 MZCs (control) were milled using a 5-axis machine (DWX-52D®, DGShape). All MZCs were sintered and scanned with the aforementioned scanner. The surface data of each sample (overall crown, marginal area, occlusal surface) were superimposed to the original CAD file (ControlX®, Geomagic) to evaluate trueness: (90-10)/2, absolute average (ABS AVG) and root mean square (RMS) values were obtained for test and control groups (MathLab®, Mathworks) and used for analysis. Finally, the clinical precision (marginal adaptation, interproximal contacts) of test and control MZCs was investigated on a split-cast model printed (Solflex350®, Voco) from the CAD project, and compared.

RESULTS

The milled MZCs had a significantly higher trueness than the 3D-printed ones, overall [(90-10)/2 printed 37.8 µm vs milled 21.2 µm; ABS AVG printed 27.2 µm vs milled 15.1 µm; RMS printed 33.2 µm vs milled 20.5 µm; p = 0.000005], at the margins [(90-10)/2 printed 25.6 µm vs milled 12.4 µm; ABS AVG printed 17.8 µm vs milled 9.4 µm; RMS printed 22.8 µm vs milled 15.6 µm; p= 0.000011] and at the occlusal level [(90-10)/2 printed 50.4 µm vs milled 21.9 µm; ABS AVG printed 29.6 µm vs milled 14.7 µm; RMS printed 38.9 µm vs milled 22.5 µm; p = 0.000005]. However, with regard to precision, both test and control groups scored highly, with no significant difference either in the quality of interproximal contact points (p = 0.355) or marginal closure (p = 0.355).

CONCLUSIONS

Milled MZCs had a statistically higher trueness than 3D-printed ones; all crowns, however, showed high precision, compatible with the clinical use.

CLINICAL SIGNIFICANCE

Although milled MZCs remain more accurate than 3D-printed ones, the LCM technique seems able to guarantee the production of clinically precise zirconia crowns.

摘要

目的

比较 3D 打印与铣削整体氧化锆冠（MZC）的真实度和精度。

方法

使用工业扫描仪（ATOSQ®，Gom）扫描上颌带预备前磨牙的模型，并在计算机辅助设计（CAD）软件（DentalCad®，Exocad）中设计 MZC。从该标准网格语言（STL）文件中，使用基于光固化的陶瓷制造（LCM）打印机（CerafabS65®，Lithoz）打印 10 个 MZC（测试），使用 5 轴机床（DWX-52D®，DGShape）铣削 10 个 MZC。所有 MZC 均经过烧结并使用上述扫描仪进行扫描。将每个样本的表面数据（整体冠、边缘区域、咬合面）叠加到原始 CAD 文件（ControlX®，Geomagic）上，以评估真实度：测试组和对照组的（90-10）/2、绝对平均值（ABS AVG）和均方根值（RMS）值（MathLab®，Mathworks）用于分析。最后，使用从 CAD 项目打印的分体式铸模（Solflex350®，Voco）研究测试和对照 MZC 的临床精度（边缘适应性、邻面接触），并进行比较。

结果

铣削 MZC 的真实度明显高于 3D 打印 MZC，整体（（90-10）/2 打印 37.8µm 与铣削 21.2µm；ABS AVG 打印 27.2µm 与铣削 15.1µm；RMS 打印 33.2µm 与铣削 20.5µm；p=0.000005），边缘（（90-10）/2 打印 25.6µm 与铣削 12.4µm；ABS AVG 打印 17.8µm 与铣削 9.4µm；RMS 打印 22.8µm 与铣削 15.6µm；p=0.000011）和咬合面（（90-10）/2 打印 50.4µm 与铣削 21.9µm；ABS AVG 打印 29.6µm 与铣削 14.7µm；RMS 打印 38.9µm 与铣削 22.5µm；p=0.000005）。然而，就精度而言，测试组和对照组的评分都很高，在邻面接触点的质量方面没有显著差异（p=0.355）或边缘封闭（p=0.355）。