Sabatini Gabriela Panca, Dönmez Mustafa Borga, Çakmak Gülce, Demirel Münir, Al-Haj Husain Nadin, Sesma Newton, Yoon Hyung-In, Yilmaz Burak
Clinical Assistant, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland; and PhD candidate, Department of Prosthodontics, School of Dentistry, University of São Paulo (USP), São Paulo, Brazil.
Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Biruni University, Istanbul, Turkey; and PhD Student, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
J Prosthet Dent. 2024 Dec;132(6):1323.e1-1323.e8. doi: 10.1016/j.prosdent.2024.09.005. Epub 2024 Sep 20.
Inorganic fillers can be incorporated into additively manufactured (AM) resins to improve their properties, and a ceramic composite concentrate has been recently marketed for this purpose. However, knowledge on the printability of AM resins modified with this concentrate is lacking.
The purpose of this in vitro study was to evaluate the manufacturing trueness and internal fit of AM crowns in a dental resin modified with a commercially available ceramic composite concentrate.
A maxillary right first molar typodont tooth was prepared and digitized to design a crown in standard tessellation language (STL) format. This STL file was used to fabricate a total of 30 AM crowns, 10 with a resin with no fillers for interim restorations (AM-I), 10 AM-I resin incorporated with ceramic composite concentrate (AM-IR), and 10 with a ceramic-filled resin intended for definitive restorations (AM-D). The modification of the AM-IR resin was performed by mechanically mixing 30 wt% of a commercially available ceramic composite concentrate into AM-I. An intraoral scanner was used to digitize all crowns, which were then seated on the prepared typodont abutment and rescanned. The manufacturing trueness of each crown was measured in 4 regions (overall, external, intaglio, and marginal) and reported with root mean square (RMS) estimates. The internal gaps were calculated by using a triple scan protocol. The intaglio surface deviations were assessed with the Kruskal-Wallis and Dunn tests, while the remaining data were analyzed with the 1-way analysis of variance and Tukey honestly significant difference tests (α=.05).
AM-IR had the highest overall and external RMS and had higher intaglio RMS than AM-D (P≤.001). AM-I had the lowest marginal RMS (P≤.002). AM-IR had the highest average gap values (P≤.027).
AM-IR crowns mostly had lower trueness and high internal gaps. However, the differences among the tested materials in fabrication trueness and average gap values were small, and internal gaps were within the previously reported thresholds.
无机填料可加入增材制造（AM）树脂中以改善其性能，最近有一种陶瓷复合浓缩物为此目的投放市场。然而，关于用这种浓缩物改性的AM树脂的可打印性的知识尚缺。
本体外研究的目的是评估用市售陶瓷复合浓缩物改性的牙科树脂中AM全冠的制造精度和内部适合性。
制备并数字化上颌右侧第一磨牙模型牙，以标准镶嵌语言（STL）格式设计全冠。该STL文件用于制作总共30个AM全冠，10个用无填料树脂制作临时修复体（AM-I），10个AM-I树脂中加入陶瓷复合浓缩物（AM-IR），10个用用于最终修复的陶瓷填充树脂制作（AM-D）。通过将30 wt%的市售陶瓷复合浓缩物机械混合到AM-I中来对AM-IR树脂进行改性。使用口腔内扫描仪对所有全冠进行数字化，然后将其就位在制备好的模型牙基台上并重新扫描。在4个区域（整体、外部、内表面和边缘）测量每个全冠的制造精度，并用均方根（RMS）估计值报告。使用三重扫描协议计算内部间隙。用Kruskal-Wallis和Dunn检验评估内表面偏差，而其余数据用单向方差分析和Tukey真实显著性差异检验进行分析（α = 0.05）。
AM-IR的整体和外部RMS最高，内表面RMS高于AM-D（P≤0.001）。AM-I的边缘RMS最低（P≤0.002）。AM-IR的平均间隙值最高（P≤0.027）。
AM-IR全冠大多精度较低且内部间隙较大。然而，测试材料在制造精度和平均间隙值方面的差异较小，且内部间隙在先前报告的阈值范围内。
