School of Dentistry and Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan; Department of Stomatology, National Cheng Kung University Hospital, Tainan, Taiwan.
School of Dentistry and Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan; Department of Stomatology, National Cheng Kung University Hospital, Tainan, Taiwan.
Dent Mater. 2024 Aug;40(8):1208-1215. doi: 10.1016/j.dental.2024.06.005. Epub 2024 Jun 8.
To investigate a near-infrared-to-blue luminescence upconversion curing method for polymerizing resin cements under zirconia discs.
Lava zirconia discs of different thicknesses (0.5-2.0 mm) were manufactured. First, the transmittances of the NIR and two blue lights (BLs) (LED and halogen lights) through these discs were measured. Second, NaYF:Yb/Tm upconversion phosphor (UP) powder was milled into 0.5-μm particle sizes. A light-curable resin cement VariolinkII base was chosen as the control (UP0), and an experimental cement (UP5) was prepared by adding 5 % UPs. These two cements were examined using multiphoton excitation microscopy for particle distribution. UP5 and UP0 were polymerized with or without zirconia shielding then subjected to a microhardness test. A multifold analysis was performed to examine the effects of zirconia thickness, curing protocols (pure BL or combined BL and NIR curing), and cement type.
The transmittance of NIR was superior to that of BL through zirconia discs of all thicknesses. UP particles were homogeneously distributed in UP5 and emitted blue luminescence under 980-nm NIR excitation. UP5 showed higher microhardness values than UP0 under any curing protocol or zirconia shielding condition. The combination of 20-s BL and 40-s NIR curing yielded the highest microhardness in uncovered UP5. However, combining 40-s BL and 20-s NIR curing surpassed the other groups when the zirconia discs were thicker than 0.5 mm.
NIR exhibits higher transmission through zirconia than BL. UP particles work as strengthen fillers and photosensitizers in cements. NIR upconversion curing could be a new strategy for polymerizing resin cements under thick zirconia restorations.
研究一种近红外-蓝光上转换固化方法，以在氧化锆片下聚合树脂水门汀。
制作不同厚度（0.5-2.0mm）的 Lava 氧化锆片。首先，测量这些片材对近红外光和两种蓝光（BL）（LED 和卤素灯）的透光率。其次，将 NaYF:Yb/Tm 上转换荧光粉（UP）研磨成 0.5μm 粒径。选择光固化树脂水门汀 VariolinkII 基作为对照（UP0），并通过添加 5%UP 制备实验性水门汀（UP5）。使用多光子激发显微镜检查这两种水门汀的颗粒分布。在有无氧化锆屏蔽的情况下对 UP5 和 UP0 进行聚合，然后进行显微硬度测试。采用多重分析方法考察氧化锆厚度、固化方案（纯 BL 或 BL 和 NIR 联合固化）和水门汀类型的影响。
在所有厚度的氧化锆片下，近红外光的透光率优于 BL。UP 颗粒在 UP5 中均匀分布，在 980nm 近红外激发下发出蓝色荧光。在任何固化方案或氧化锆屏蔽条件下，UP5 的显微硬度值均高于 UP0。在未覆盖的 UP5 中，20s BL 和 40s NIR 联合固化产生的显微硬度最高。然而，当氧化锆片厚度大于 0.5mm 时，40s BL 和 20s NIR 联合固化的组合优于其他组。
近红外光在氧化锆中的透过率高于 BL。UP 颗粒在水门汀中作为增强填料和光敏剂。NIR 上转换固化可能是在厚氧化锆修复体下聚合树脂水门汀的一种新策略。
