Graduate student, Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China.
Clinical Associate Professor, Department Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
J Prosthet Dent. 2024 Nov;132(5):985.e1-985.e7. doi: 10.1016/j.prosdent.2023.04.008. Epub 2023 May 20.
The nanoparticle jetting (NPJ) technique is a recently developed additive manufacturing method that may have useful dental applications. The manufacturing accuracy and clinical adaptation of zirconia monolithic crowns fabricated with NPJ are unknown.
The purpose of this in vitro study was to compare the dimensional accuracy and clinical adaptation of zirconia crowns fabricated with NPJ and those fabricated with subtractive manufacturing (SM) and digital light processing (DLP).
Five standardized typodont right mandibular first molars were prepared for ceramic complete crowns, and 30 zirconia monolithic crowns were fabricated using SM, DLP, and NPJ (n=10) with a completely digital workflow. The dimensional accuracy at the external, intaglio, and marginal areas was determined by superimposing the scanned data and computer-aided design data of the crowns (n=10). Occlusal, axial, and marginal adaptations were evaluated by using a nondestructive silicone replica and dual scanning method. The 3-dimensional discrepancy was evaluated to determine clinical adaptation. Differences among test groups were analyzed by using a MANOVA and the post hoc least significant difference test for normally distributed data or the Kruskal-Wallis test with Bonferroni correction for nonnormally distributed data (α=.05).
Significant differences were found in the dimensional accuracy and clinical adaptation among the groups (P<.001). The NPJ group had a lower overall root mean square (RMS) value for dimensional accuracy (22.9 ±1.4 μm) than the SM (27.3 ±5.0 μm) and DLP (36.4 ±5.9 μm) groups (P<.001). The NPJ group had a lower external RMS value (23.0 ±3.0 μm) than the SM group (28.9 ±5.4 μm) (P<.001) and equivalent marginal and intaglio RMS values than the SM group. The DLP group had larger external (33.3 ±4.3 μm), intaglio (36.1 ±10.7 μm), and marginal (79.4 ±12.9 μm) deviations than the NPJ and SM groups (P<.001). With regard to clinical adaptation, the marginal discrepancy was smaller in the NPJ group (63.9 ±27.3 μm) than in the SM group (70.8 ±27.5 μm) (P<.001). No significant differences were found between the SM and NPJ groups in terms of the occlusal (87.2 ±25.5 and 80.5 ±24.2 μm, respectively) and axial (39.1 ±19.7 and 38.4 ±13.7 μm, respectively) discrepancies. The DLP group had larger occlusal (239.0 ±60.1 μm), axial (84.9 ±29.1 μm), and marginal (140.4 ±84.3 μm) discrepancies than the NPJ and SM groups (P<.001).
Monolithic zirconia crowns fabricated using NPJ have higher dimensional accuracy and clinical adaptation than those fabricated using SM or DLP.
纳米颗粒喷射（NPJ）技术是一种最近开发的增材制造方法，可能在牙科中有有用的应用。使用 NPJ 制造的氧化锆整体冠的制造精度和临床适应性尚不清楚。
本体外研究的目的是比较使用 NPJ、减法制造（SM）和数字光处理（DLP）制造的氧化锆冠的尺寸精度和临床适应性。
对 5 颗标准化的下颌第一磨牙进行全瓷冠预备，使用 SM、DLP 和 NPJ（n=10）以完全数字化的工作流程制造 30 个氧化锆整体冠。通过叠加冠的扫描数据和计算机辅助设计数据来确定外部、凹面和边缘区域的尺寸精度（n=10）。使用非破坏性硅橡胶复制和双重扫描方法评估牙合面、轴向和边缘适应性。通过三维差异评估确定临床适应性。使用多变量方差分析和事后最小显著差异检验（对于正态分布数据）或 Kruskal-Wallis 检验和 Bonferroni 校正（对于非正态分布数据）（α=.05）分析测试组之间的差异。
组间在尺寸精度和临床适应性方面存在显著差异（P<.001）。NPJ 组的整体根均方误差（RMS）值（22.9 ±1.4 μm）低于 SM（27.3 ±5.0 μm）和 DLP（36.4 ±5.9 μm）组（P<.001）。NPJ 组的外部 RMS 值（23.0 ±3.0 μm）低于 SM 组（28.9 ±5.4 μm）（P<.001），与 SM 组的边缘和凹面 RMS 值相当。DLP 组的外部（33.3 ±4.3 μm）、凹面（36.1 ±10.7 μm）和边缘（79.4 ±12.9 μm）偏差均大于 NPJ 和 SM 组（P<.001）。关于临床适应性，NPJ 组的边缘差异（63.9 ±27.3 μm）小于 SM 组（70.8 ±27.5 μm）（P<.001）。SM 和 NPJ 组之间的牙合面（87.2 ±25.5 和 80.5 ±24.2 μm，分别）和轴向（39.1 ±19.7 和 38.4 ±13.7 μm，分别）差异无统计学意义。DLP 组的牙合面（239.0 ±60.1 μm）、轴向（84.9 ±29.1 μm）和边缘（140.4 ±84.3 μm）偏差均大于 NPJ 和 SM 组（P<.001）。
与 SM 或 DLP 相比，使用 NPJ 制造的整体氧化锆冠具有更高的尺寸精度和临床适应性。
