背景:诊断模型可以结合不同的基础设计,并使用不同的桶聚合技术制造。然而,基础设计和3D打印技术之间的相互关系对最终精度的影响尚不清楚。
目的:这项体外研究的目的是评估3D打印铸模的不同基础设计对2桶聚合技术准确性的影响。
方法:获得了数字上颌铸模,并用于生成3种不同的基础设计:实心(S组),蜂窝(HC组),和空心(H组)。HC和H组根据铸件设计的壁厚进行了细分,导致2个小组的厚度为1毫米(HC1和H1)和2毫米(HC2和H2)(N=100,n=10)。将11个参考立方体添加到每个样品中用于随后的测量。通过使用2台聚合3D打印机制造样本:Nextdent5100(ND组)和SonicMini4K(SM4K组)以及适用于两种3D打印机的树脂材料(NextdentModel2.0)。坐标测量机量化了数字铸件与每个参考样本之间的线性和3维差异。真实性定义为虚拟铸件和通过增材制造(AM)生产的样品之间的平均绝对尺寸差异,而精度被描述为数字铸件和AM标本之间尺寸差异的标准偏差。使用Kruskal-Wallis和Mann-WhitneyU成对比较试验(α=.05)分析数据。
结果:对于NextDent组,正确度范围为21.83µm至28.35µm,精度范围为17.82µm至37.70µm。对于Phrozen小组,真实性范围从45.15µm到64.51µm,精度范围从33.51µm到48.92µm。Kruskal-Wallis检验在x-,-,和z轴以及3D差异(所有P<.001)。在x轴上,Mann-WhitneyU检验显示Phrozen组在H-2和H-1组之间存在显着差异(P=.001),H-2和S组(P<0.001),HC-2和S组(P=0.012)。在y轴上,在Phrozen组中,H-2组和H-1组之间存在显着差异(P=.001),H-2和S,H-1和HC-1,以及HC-1和S基团(P<0.001),H-1和HC-2基团(P=0.007),以及HC-2和S基团(P=0.009)。NextDent组表现出显著差异,特别是在HC-1和H-2基团中(P=0.004),H-1(P=.020),和HC-2组(P=.001);在z轴上,Phrozen组在H-2,H-1和S组和HC-2组和H-1和S组之间存在显着差异(均P<.001)。在“NextDent”组中,H-2和HC-2(P=0.047)和HC-1(P=0.028)组之间存在显着差异。对于3D差异分析,在Phrozen组中,H-2组和H-1和S组之间存在显着差异(P<.001),H-1和HC-2基团(P=0.001),S和HC-1和HC-2基团(P<.001),以及H-1和HC-1基团(P=0.002)。在“NextDent”组中,在H-2组和HC-1组之间观察到显著差异(P=0.012)。
结论:数字演员表的准确性取决于演员表的制造三项式和基础设计。基于蜂窝和中空的设计分别为所测试的材料聚合物在NextDent和Phrozen组中提供了最高的精度。所有样本落在临床上可接受的范围内。
BACKGROUND: Diagnostic casts can incorporate different base designs and be manufactured using different vat-polymerization technologies. However, the influence of the interrelation between the base design and the 3D printing technology on the casts\' final accuracy remains unclear.
OBJECTIVE: The purpose of this in vitro study was to assess the influence of different base designs of 3D printed casts on the accuracy of 2 vat-polymerization technologies.
METHODS: A digital maxillary cast was obtained and used to generate 3 different base designs: solid (S group), honeycombed (HC group), and hollow (H group). The HC and H groups were subdivided based on the wall thickness of the cast design, resulting in 2 subgroups with thicknesses of 1 mm (HC1 and H1) and 2 mm (HC2 and H2) (N=100, n=10). Eleven reference cubes were added to each specimen for subsequent measurements. Specimens were manufactured by using 2 vat-polymerization 3D printers: Nextdent 5100 (ND group) and Sonic Mini 4K (SM4K group) and a resin material suitable for both 3D printers (Nextdent Model 2.0). A coordinate measuring machine quantified the linear and 3-dimensional discrepancies between the digital cast and each reference specimen. Trueness was defined as the average absolute dimensional discrepancy between the virtual cast and the specimens produced through additive manufacturing (AM), while precision was delineated as the standard deviation in dimensional discrepancies between the digital cast and the AM specimens. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U pairwise comparison tests (α=.05).
RESULTS: For the NextDent group the trueness ranged from 21.83 µm to 28.35 µm, and the precision ranged from 17.82 µm to 37.70 µm. For the Phrozen group, the trueness ranged from 45.15 µm to 64.51 µm, and the precision ranged from 33.51 µm to 48.92 µm. The Kruskal-Wallis test showed significant differences on the x-, y-, and z-axes and in the 3D discrepancy (all P<.001). On the x-axis, the Mann-Whitney U test showed significant differences for the Phrozen group between the H-2 and H-1 groups (P=.001), H-2 and S groups (P<.001), and HC-2 and S groups (P=.012). On the y-axis, significant differences were found in the Phrozen group between the H-2 and H-1 groups (P=.001), the H-2 and S, H-1 and HC-1, and HC-1 and S groups (P<.001), the H-1 and HC-2 groups (P=.007), and the HC-2 and S groups (P=.009). The NextDent group exhibited significant differences, particularly among the HC-1 and H-2 groups (P=.004), H-1 (P=.020), and HC-2 (P=.001) groups; and on the z-axis significant differences were found in the Phrozen group between the H-2 and H-1 and S groups and the HC-2 group and H-1 and S groups (both P<.001). In the NextDent group, significant differences were found between the H-2 and HC-2 (P=.047) and HC-1 (P=.028) groups. For the 3D discrepancy analysis, significant differences were found in the Phrozen group between the H-2 and H-1 and S groups (P<.001), the H-1 and HC-2 groups (P=.001), the S and HC-1 and HC-2 groups (P<.001), and the H-1 and HC-1 groups (P=.002). In the NextDent group, significant differences were observed between the H-2 and HC-1 groups (P=.012).
CONCLUSIONS: The accuracy of digital casts depends on the manufacturing trinomial and base design of the casts. The honeycomb and hollow based designs provided the highest accuracy in the NextDent and Phrozen groups respectively for the material polymer tested. All specimens fell in the clinically acceptable range.