Izzettinoglu Eymen, Eroglu Erdal
Department of Prosthodontics, Faculty of Dentistry, Suleyman Demirel University, Isparta, 32000, Turkey.
BMC Oral Health. 2025 Apr 30;25(1):671. doi: 10.1186/s12903-025-06056-5.
Comprehending the synergistic of surface treatments and oral environmental factors is paramount for optimizing the performance of 3D-printed dentures. This study evaluates flexural strength, hardness, roughness, and color stability of 3D-printed resins after two surface treatments and coffee thermocycling, to establish alternative polishing efficacy.
Rectangular test specimens (64 × 10 × 3.3 ± 0.2 mm) were fabricated from a conventional heat-cured denture base material (Probase HC, n = 20) and four 3D-printed denture base materials (Nextdent; ND, Formlabs; FL, Senertek; ST, Powerresin; PR, n = 40 per group), resulting in a total sample size of N = 180. Specimens were randomly assigned to undergo either mechanical polishing or glazing, followed by 5000 cycles of coffee thermocycling (CTC). Color change (ΔE) and surface roughness (Ra) were assessed both prior to and subsequent to CTC. Subsequently, the specimens were subjected to a 3-point bending test and a Vickers microhardness (VH) test. Statistical analysis of the data was performed using descriptive and analytical methods, with a significance level set at α = 0.05.
The application of Vita Akzent LC (VA) as a glaze material, while conferring supplementary protection against surface degradation during coffee thermocycling (CTC), resulted in a statistically significant increase in the initial surface roughness (Ra) values across all experimental 3D-printed groups (p < 0.05). It reduced the ΔE value of the FL group (p = 0.036) but did not have a statistically significant impact on the ΔE of other 3D-printed groups (p˃0.05). Additionally, VA enhanced the VH of most 3D-printed groups (p < 0.05). It improved the flexural strength of the PR and ST groups but decreased it for the FL group and had no significant effect on the ND group (p = 0.088). The mechanically polished specimens demonstrated acceptable Ra, ΔE, and flexural strength values. However, they showed a lower VH than the glazed specimens.
Glaze application resulted in improved mechanical strength and hardness for the majority of 3D-printed groups; however, its capacity to effectively reduce surface roughness and discoloration was consistently limited. Conversely, mechanical polishing maintained its beneficial effects, demonstrating clinically acceptable values across all assessed parameters. Therefore, comprehensive additional investigations are necessitated to fully elucidate the performance characteristics of glaze materials and their interactions with 3D-printed denture base materials.
了解表面处理与口腔环境因素之间的协同作用对于优化3D打印假牙的性能至关重要。本研究评估了两种表面处理和咖啡热循环后3D打印树脂的弯曲强度、硬度、粗糙度和颜色稳定性，以确定替代抛光效果。
使用传统热固化义齿基托材料（Probase HC，n = 20）和四种3D打印义齿基托材料（NextDent；ND、Formlabs；FL、Senertek；ST、Powerresin；PR，每组n = 40）制作矩形测试样本（64×10×3.3±0.2 mm），总样本量为N = 180。样本被随机分配进行机械抛光或上釉，然后进行5000次咖啡热循环（CTC）。在CTC前后评估颜色变化（ΔE）和表面粗糙度（Ra）。随后，对样本进行三点弯曲试验和维氏显微硬度（VH）试验。使用描述性和分析性方法对数据进行统计分析，显著性水平设定为α = 0.05。
使用Vita Akzent LC（VA）作为釉料，虽然在咖啡热循环（CTC）期间能提供额外的表面降解保护，但所有实验3D打印组的初始表面粗糙度（Ra）值均有统计学显著增加（p < 0.05）。它降低了FL组的ΔE值（p = 0.036），但对其他3D打印组的ΔE没有统计学显著影响（p > 0.05）。此外，VA提高了大多数3D打印组的VH（p < 0.05）。它提高了PR组和ST组的弯曲强度，但降低了FL组的弯曲强度，对ND组没有显著影响（p = 0.088）。机械抛光的样本显示出可接受的Ra、ΔE和弯曲强度值。然而，它们的VH低于上釉样本。
上釉使大多数3D打印组的机械强度和硬度得到改善；然而，其有效降低表面粗糙度和变色的能力一直有限。相反，机械抛光保持了其有益效果，在所有评估参数中均显示出临床可接受的值。因此，需要进行全面的额外研究，以充分阐明釉料材料的性能特征及其与3D打印义齿基托材料的相互作用。
