Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, 12220-000, Brazil.
Aeronautics Technological Institute (ITA), 50 Praça Marechal Eduardo Gomes, São José dos Campos, 12228-900, São Paulo State, Brazil.
Clin Oral Investig. 2024 Oct 31;28(11):617. doi: 10.1007/s00784-024-06003-8.
This study evaluated the mechanical, optical, microstructural, surface, and adhesive behavior of a 3D printing resin comparing it with a machinable resin composite.
Specimens of different sizes and shapes were either printed (Vitality, Smart Dent) or machinable (Grandio Blocs, Voco GmbH) resin composites with similar composition were prepared. Surface and mechanical characterization were performed with Knoop hardness, flexural strength (three-point-bending), and elastic modulus tests. The wear of the tested materials was evaluated against steatite antagonists. The optical properties stability (color change, ΔE and translucency, TP) were observed after staining in red wine. In addition, the bond strength of the resin composites to two resin cement protocols were investigated with microshear bond strength tests at baseline and after thermocycling. Scanning electron microscope (SEM) coupled with Energy-Dispersive X-ray Spectroscopy (EDS) was used for microstructural and chemical characterization. Statistical analyses were performed with t- and ANOVA tests.
Hardness values (132.76 (16.32) KH- Machinable and 35.87 (2.78) KH - Printed), flexural strength (172.17 (26.99) MPa - Machinable and 88.69 (8.39) MPa - Printed), color and translucency change (1.86 (0.31)/0.06 - Machinable and 3.73 (0.36)/9,16- Printed), and wear depth (24.97 mm (3.60)- Machinable and 7.16 mm (2.84) - Printed) were statistically different. Average Regarding bond strength, mean values (MPa) for non-aged and aged groups were respectively 21.76 (6.64) / 31.9 (12.66) for Bifix cement (Voco GmbH, Cuxhaven, Germany) and 26.75 (5.14) / 24.36 (6.85) for Variolink cement (Ivoclar Vivadent, Schaan, Liechtenstein) in Printed and 17.79 (3.89) / 9.01 (3.36) ) for Bifix cement and 22.09 (6.55) / 11.01 (3.77) for Variolink cement in Machinable materials. The material and aging factors did affect bond strength but the cement factor did not (p = 0.202). No statistical differences were observed for mean roughness (Ra) between materials. The better dispersion and larger size of the inorganic particles in the Machinable resin were contrasted with the clustered smaller particles of printed resin, under SEM.
The mechanical properties and color stability of the machinable resin were superior to those of the printed resin, probably due to the greater amount and dispersion of inorganic particles in the Mach resin, but bond strength after aging was stronger and more stable in the printed resin.
3D-printed resin composites with similar compositions to machinable resin composites do not necessarily exhibit the same properties, which can impact clinical performance. Understanding these differences can assist manufacturers in improving their materials and help clinicians distinguish between materials appropriate for provisional and final restorations.
本研究评估了一种 3D 打印树脂的机械性能、光学性能、微观结构、表面性能和黏附性能，并将其与可加工树脂复合材料进行比较。
采用不同尺寸和形状的试件，通过 3D 打印（Vitality、Smart Dent）或机加工（Grandio Blocs、Voco GmbH）制备具有相似组成的树脂复合材料。通过显微硬度、三点弯曲法和弹性模量试验对表面和机械性能进行了评估。使用滑石对测试材料进行磨损试验。评估了染色前后材料的光学稳定性（颜色变化、ΔE 和透光率、TP），染色试剂为红酒。此外，还通过微剪切结合强度试验在基线和热循环后研究了两种树脂水门汀与树脂复合材料的黏结强度。采用扫描电子显微镜（SEM）和能谱仪（EDS）进行微观结构和化学特性分析。采用 t 检验和方差分析进行统计学分析。
硬度值（132.76（16.32）KH-可加工和 35.87（2.78）KH-打印）、弯曲强度（172.17（26.99）MPa-可加工和 88.69（8.39）MPa-打印）、颜色和透光率变化（1.86（0.31）/0.06-可加工和 3.73（0.36）/9.16-打印）和磨损深度（24.97mm（3.60）-可加工和 7.16mm（2.84）-打印）存在统计学差异。关于黏结强度，非老化和老化组的平均（MPa）值分别为 21.76（6.64）/31.9（12.66）（Voco GmbH，Cuxhaven，德国的 Bifix 水门汀）和 26.75（5.14）/24.36（6.85）（Ivoclar Vivadent，Schaan，列支敦士登的 Variolink 水门汀）在打印材料中，17.79（3.89）/9.01（3.36））（Voco GmbH，Cuxhaven，德国的 Bifix 水门汀）和 22.09（6.55）/11.01（3.77）（Ivoclar Vivadent，Schaan，列支敦士登的 Variolink 水门汀）在可加工材料中。材料和老化因素会影响黏结强度，但水门汀因素没有影响（p=0.202）。材料之间的平均粗糙度（Ra）没有观察到统计学差异。可加工树脂中的无机颗粒分散性更好，尺寸更大，而打印树脂中的无机颗粒则呈簇状，尺寸更小，这一点在 SEM 下观察得很明显。
可加工树脂的机械性能和颜色稳定性优于打印树脂，可能是因为可加工树脂中的无机颗粒含量更多，分散性更好，但老化后打印树脂的黏结强度更强且更稳定。
与可加工树脂复合材料具有相似成分的 3D 打印树脂复合材料不一定具有相同的性能，这可能会影响临床性能。了解这些差异可以帮助制造商改进他们的材料，并帮助临床医生区分适用于临时和最终修复的材料。
