Grob Benjamin, Fässler Pascal, Lamparth Iris, Omeragic Sadini, Rist Kai, Vidal Loïc, Lalevée Jacques, Catel Yohann
Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein.
Institut de Science des Matériaux de Mulhouse, Université de Haute-Alsace, CNRS, IS2M UMR 7361, 68100 Mulhouse, France.
Polymers (Basel). 2025 Jun 26;17(13):1761. doi: 10.3390/polym17131761.
The development of high-impact denture base formulations that are suitable for digital light processing (DLP) 3D printing is demanding. Indeed, a combination of high flexural strength/modulus and high fracture toughness is required. In this contribution, eight urethane macromonomers () were synthesized in a one-pot, two-step procedure. Several rigid diols were first reacted with two equivalents of trimethylhexamethylene diisocyanate. The resulting diisocyanates were subsequently end-capped with a free-radically polymerizable monomer bearing a hydroxy group. were combined with the monofunctional monomer (octahydro-4,7-methano-1H-indenyl)methyl acrylate and a poly(ε-caprolactone)-polydimethylsiloxane-poly(ε-caprolactone) (PCL-PDMS-PCL) triblock copolymer () as a toughening agent. The double-bond conversion, glass transition temperature (T), and mechanical properties (flexural strength/modulus, fracture toughness) of corresponding light-cured materials were measured (cured in a mold using a light-curing unit). The results showed that the incorporation of was highly efficient at significantly increasing the fracture toughness, as long as the obtained networks exhibited a low crosslink density. The structure of the urethane macromonomer (nature of the rigid group in the spacer; nature and number of polymerizable groups) was demonstrated to be crucial to reach the desired properties (balance between flexural strength/modulus and fracture toughness). Amongst the evaluated macromonomers, and were particularly promising. By correctly adjusting the content, light-cured formulations based on those two urethane dimethacrylates were able to fulfill ISO20795-1:2013 standard requirements regarding high-impact materials. These formulations are therefore suitable for the development of 3D printable high-impact denture bases.
开发适用于数字光处理（DLP）3D打印的高冲击义齿基托配方颇具挑战性。实际上，需要兼具高弯曲强度/模量和高断裂韧性。在本研究中，通过一锅两步法合成了八种聚氨酯大分子单体。首先使几种刚性二醇与两当量的三甲基六亚甲基二异氰酸酯反应。随后，所得的二异氰酸酯用带有羟基的可自由基聚合单体进行封端。将其与单官能单体丙烯酸（八氢-4,7-亚甲基-1H-茚基）甲酯和聚（ε-己内酯）-聚二甲基硅氧烷-聚（ε-己内酯）（PCL-PDMS-PCL）三嵌段共聚物作为增韧剂进行混合。测量了相应光固化材料的双键转化率、玻璃化转变温度（T）和机械性能（弯曲强度/模量、断裂韧性）（在模具中使用光固化单元进行固化）。结果表明，只要所得网络表现出低交联密度，加入该三嵌段共聚物能非常有效地显著提高断裂韧性。结果表明，聚氨酯大分子单体的结构（间隔基中刚性基团的性质；可聚合基团的性质和数量）对于达到所需性能（弯曲强度/模量与断裂韧性之间的平衡）至关重要。在所评估的大分子单体中，两种表现尤为突出。通过正确调整其含量，基于这两种聚氨酯二甲基丙烯酸酯的光固化配方能够满足ISO20795-1:2013标准对高冲击材料的要求。因此，这些配方适用于开发3D可打印的高冲击义齿基托。
