Novel Polymerization of Dental Composites Using Near-Infrared-Induced Internal Upconversion Blue Luminescence

Polymers

Jui-Che Lin¹  Tsung-Lin Lee²  Chu-Chun Liao³  Yu-Cheng Chou³  Ting-Wen Lai³  Shu-Fen Chuang³ 

[1] Department of Chemical Engineering, National Cheng Kung University, No.1 Universal Road, Tainan 70101, Taiwan;Department of Stomatology, National Cheng Kung University Hospital, 138 ShengLi Road, Tainan 70403, Taiwan;School of Dentistry and Institute of Oral Medicine, National Cheng Kung University, No.1 Universal Road, Tainan 70101, Taiwan;

关键词: resin composite;    polymerization;    upconversion;    near-infrared;    microhardness;   

DOI  :  10.3390/polym13244304

来源: DOAJ

【 摘 要 】

Blue light (BL) curing on dental resin composites results in gradient polymerization. By incorporating upconversion phosphors (UP) in resin composites, near-infrared (NIR) irradiation may activate internal blue emission and a polymerization reaction. This study was aimed to evaluate the competency of the NIR-to-BL upconversion luminance in polymerizing dental composites and to assess the appropriate UP content and curing protocol. NaYF₄ (Yb³⁺/Tm³⁺ co-doped) powder exhibiting 476-nm blue emission under 980-nm NIR was adapted and ball-milled for 4–8 h to obtain different particles. The bare particles were assessed for their emission intensities, and also added into a base composite Z100 (3M EPSE) to evaluate their ability in enhancing polymerization under NIR irradiation. Experimental composites were prepared by dispensing the selected powder and Z100 at different ratios (0, 5, 10 wt% UP). These composites were irradiated under different protocols (BL, NIR, or their combinations), and the microhardness at the irradiated surface and different depths were determined. The results showed that unground UP (d50 = 1.9 μm) exhibited the highest luminescence, while the incorporation of 0.4-μm particles obtained the highest microhardness. The combined 20-s BL and 20–120-s NIR significantly increased the microhardness on the surface and internal depths compared to BL correspondents. The 5% UP effectively enhanced the microhardness under 80-s NIR irradiation but was surpassed by 10% UP with longer NIR irradiation. The combined BL-NIR curing could be an effective approach to polymerize dental composites, while the intensity of upconversion luminescence was related to specific UP particle size and content. Incorporation of 5–10% UP facilitates NIR upconversion polymerization on dental composites.

【 授权许可】

Unknown