3D列印丙烯酸共聚物於假牙基底與隱形牙套應用之材料特性研究

Abstract

本研究探討超分枝高分子聚氨酯丙烯酸酯（hyperbranched polyurethane acrylate, HBPUA）對3D列印假牙基底與隱形牙套樹脂材料性質之影響。實驗以三羥基單體（B3）、二異氰酸酯（A2）及含羥基丙烯酸酯（BR）合成HBPUA，並命名為TIH4。於假牙基底材料部分，選用三環癸烷二甲醇二丙烯酸酯（tricyclodecanedimethanol diacrylate, TCDDMDA）作為主要反應性稀釋劑，將10 wt% TIH4與90 wt% TCDDMDA混合形成樹脂（TC10），並依據ISO 20795-1:2013標準進行機械性質測試，並與市售假牙基底樹脂NextDent Denture 3D+進行比較。 在隱形牙套材料方面，選用三乙二醇二甲基丙烯酸酯（triethylene glycol dimethacrylate, TEGDMA）、甲基丙烯酸羥乙酯（2-hydroxyethyl methacrylate, HEMA）及聚乙二醇（200）二甲基丙烯酸酯（polyethylene glycol (200) dimethacrylate, PEG(200)DMA）作為反應性稀釋劑。以5 wt% TIH4為基礎，設計四種不同配方，分別為TT 5:95、TTP 5:60:35 、TTH 5:80:15及TTH 5:70:25，並依據ISO 20795-2:2013標準進行測試，並與市售隱形牙套樹脂LuxCreo DCA進行比較。 結果顯示，假牙基底實驗組樹脂之機械性質均優於市售對照組 NextDent Denture 3D+，顯示HBPUA所形成之超分枝結構可有效提升材料之機械性能，並降低與水分相關之劣化行為。此外，所有假牙基底實驗組材料皆符合ISO 20795-1:2013及ISO 10993-5之規範要求。 在隱形牙套樹脂方面，實驗組具有較佳之抗彎強度、彎曲模數、應力鬆弛能力及透明度，且均符合ISO 20795-2:2013之規範要求。然而，其吸水率仍高於市售材料 LuxCreo DCA。生物相容性評估結果顯示，經 60°C 水浴 72 小時及 37°C 20% 酒精浸泡 48 小時後再於 37°C 水浴 24 小時之前處理後，除 TT 5:95 組於 60°C 水浴 72 小時前處理後之 72 小時萃取組未符合 ISO 10993-5 細胞存活率要求外，其餘各組皆符合標準，顯示材料具有良好的生物相容性。 綜上所述，本研究成功開發兼具優異材料性能之直接3D列印丙烯酸共聚物。所開發之假牙基底樹脂整體性能優於市售材料 NextDent Denture 3+；而隱形牙套樹脂亦展現良好的應用潛力，未來若能進一步改善吸水率及生物相容性，將有望成為直接3D列印隱形牙套之候選材料。

This study investigated the effects of hyperbranched polyurethane acrylate (HBPUA) on the properties of 3D-printed denture base and clear aligner resins. HBPUA, designated as TIH4, was synthesized using a triol monomer (B3), a diisocyanate (A2), and a hydroxyl-containing acrylate monomer (BR). For denture base materials, tricyclodecanedimethanol diacrylate (TCDDMDA) was used as the primary reactive diluent. A resin formulation consisting of 10 wt% TIH4 and 90 wt% TCDDMDA (TC10) was prepared and evaluated according to ISO 20795-1:2013. Its properties were compared with those of the commercially available denture base resin NextDent Denture 3D+. For clear aligner materials, triethylene glycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA), and polyethylene glycol (200) dimethacrylate (PEG(200)DMA) were employed as reactive diluents. Based on a formulation containing 5 wt% TIH4, four experimental resins were developed: TT 5:95, TTP 5:60:35, TTH 5:80:15, and TTH 5:70:25. These materials were evaluated according to ISO 20795-2:2013 and compared with the commercially available clear aligner resin LuxCreo DCA. The results demonstrated that the experimental denture base resins exhibited superior mechanical properties compared with the commercial control, NextDent Denture 3D+. The hyperbranched structure formed by HBPUA effectively enhanced the mechanical performance of the materials while reducing water-related degradation. Furthermore, all experimental denture base resins satisfied the requirements of ISO 20795-1:2013 and ISO 10993-5. The experimental clear aligner resins also exhibited higher flexural strength and flexural modulus than the commercial control and fulfilled the requirements of ISO 20795-2:2013. In addition, they demonstrated significantly improved stress relaxation performance and transparency compared with LuxCreo DCA. However, the experimental clear aligner resins showed higher water sorption than LuxCreo DCA. Biocompatibility evaluation revealed that, following pretreatment by either immersion in 60°C water for 72 h or immersion in 20% ethanol at 37°C for 48 h followed by immersion in water at 37°C for 24 h, all experimental groups met the cell viability requirement specified in ISO 10993-5, except for the TT 5:95 group after the 60°C water pretreatment with a 72 h extraction period, indicating favorable biocompatibility of the developed materials. In conclusion, the HBPUA-based acrylic copolymers developed in this study demonstrated excellent potential for direct 3D printing of both denture bases and clear aligners. The denture base resins exhibited overall performance superior to that of the commercial material NextDent Denture 3D+, while the clear aligner resins also showed promising properties for direct 3D printing applications. Further optimization to reduce water sorption and improve biocompatibility may facilitate their future clinical application as directly 3D-printed clear aligners.