Hata Kentaro, Ikeda Hiroshi, Nagamatsu Yuki, Masaki Chihiro, Hosokawa Ryuji, Shimizu Hiroshi
Division of Oral Reconstruction and Rehabilitation, Department of Oral Functions, Kyushu Dental University, Fukuoka 803-8580, Japan.
Division of Biomaterials, Department of Oral Functions, Kyushu Dental University, Fukuoka 803-8580, Japan.
Polymers (Basel). 2021 Dec 17;13(24):4435. doi: 10.3390/polym13244435.
Poly(methyl methacrylate) (PMMA) is widely used in dental applications. However, PMMA specialized for stereolithography (SLA) additive manufacturing (3D-printing) has not been developed yet. This study aims to develop a novel PMMA-based resin for SLA 3D-printing by mixing methyl methacrylate (MMA), ethylene glycol dimethacrylate (EGDMA), and PMMA powder in various mixing ratios. The printability and the viscosity of the PMMA-based resins were examined to determine their suitability for 3D-printing. The mechanical properties (flexural strength and Vickers hardness), shear bond strength, degree of conversion, physicochemical properties (water sorption and solubility), and cytotoxicity for L929 cells of the resulting resins were compared with those of three commercial resins: one self-cured resin and two 3D-print resins. EGDMA and PMMA were found to be essential components for SLA 3D-printing. The viscosity increased with PMMA content, while the mechanical properties improved as EGDMA content increased. The shear bond strength tended to decrease as EGDMA increased. Based on these characteristics, the optimal composition was determined to be 30% PMMA, 56% EGDMA, 14% MMA with flexural strength (84.6 ± 7.1 MPa), Vickers hardness (21.6 ± 1.9), and shear bond strength (10.5 ± 1.8 MPa) which were comparable to or higher than those of commercial resins. The resin's degree of conversion (71.5 ± 0.7%), water sorption (19.7 ± 0.6 μg/mm), solubility (below detection limit), and cell viability (80.7 ± 6.2% at day 10) were all acceptable for use in an oral environment. The printable PMMA-based resin is a potential candidate material for dental applications.
聚甲基丙烯酸甲酯（PMMA）在牙科应用中广泛使用。然而，专门用于立体光刻（SLA）增材制造（3D打印）的PMMA尚未开发出来。本研究旨在通过以不同混合比例混合甲基丙烯酸甲酯（MMA）、乙二醇二甲基丙烯酸酯（EGDMA）和PMMA粉末，开发一种用于SLA 3D打印的新型PMMA基树脂。研究了PMMA基树脂的可打印性和粘度，以确定它们对3D打印的适用性。将所得树脂的机械性能（弯曲强度和维氏硬度）、剪切粘结强度、转化率、物理化学性能（吸水率和溶解度）以及对L929细胞的细胞毒性与三种商业树脂进行了比较：一种自固化树脂和两种3D打印树脂。发现EGDMA和PMMA是SLA 3D打印的必需成分。粘度随PMMA含量增加而增加，而机械性能随EGDMA含量增加而改善。随着EGDMA增加，剪切粘结强度趋于降低。基于这些特性，确定最佳组成为30% PMMA、56% EGDMA、14% MMA，其弯曲强度（84.6±7.1 MPa）、维氏硬度（21.6±1.9）和剪切粘结强度（10.5±1.8 MPa）与商业树脂相当或更高。该树脂的转化率（71.5±0.7%）、吸水率（19.7±0.6μg/mm）、溶解度（低于检测限）和细胞活力（第10天为80.7±6.2%）在口腔环境中使用都是可接受的。这种可打印的PMMA基树脂是牙科应用的潜在候选材料。
