Department of Dental Materials, Endodontics and Operative Dentistry, Bauru School of Dentistry-FOB-USP, Al. Octávio Pinheiro Brisolla, 9-75, 17012-901, Bauru, SP, Brazil.
Department of Dentistry, State University of Maringa, Av. Mandacaru, 1550, 87080-000, Maringá, PR, Brazil.
Dent Mater. 2019 Apr;35(4):564-573. doi: 10.1016/j.dental.2019.01.006. Epub 2019 Jan 30.
Glass-ionomer cements (GICs) modified with cellulose nanocrystals (CNs) were characterized and evaluated for compressive strength (CS), diametral tensile strength (DTS) and fluoride release (F).
Commercially available GICs (Maxxion, Vidrion R, Vitro Molar, Ketac Molar Easy Mix and Fuji Gold Label 9) were reinforced with CNs (0.2% by weight). The microstructure of CNs and of CN-modified GICs were evaluated by transmission electron microscopy (TEM) and by scanning electron microscopy (SEM) while chemical characterization was by Fourier transform infrared spectroscopy (FTIR). Ten specimens each of the unmodified (control) and CN-modified materials (test materials) were prepared for CS and DTS testing. For the fluoride release evaluation, separate specimens (n=10) of each test and control material were made. The results obtained were submitted to the t-test (p<0.05).
The CN reinforcement significantly improved the mechanical properties and significantly increased the F release of all GICs (p<0.05). The GICs with CNs showed a fibrillar aggregate of nanoparticles interspersed in the matrix. The compounds with CNs showed a higher amount of C compared to the controls due to the organic nature of the CNs. It was not possible to identify by FTIR any chemical bond difference in the compounds formed when nanofibers were inserted in the GICs.
Modification of GICs with CNs appears to produce promising restorative materials.
用纤维素纳米晶（CNs）改性的玻璃离子水门汀（GICs）的抗压强度（CS）、直径拉伸强度（DTS）和氟释放（F）进行了表征和评估。
用 CNs（重量比 0.2%）对市售 GICs（Maxxion、Vidrion R、Vitro Molar、Ketac Molar Easy Mix 和 Fuji Gold Label 9）进行了增强。通过透射电子显微镜（TEM）和扫描电子显微镜（SEM）评估了 CN 和 CN 改性 GIC 的微观结构，而化学特性则通过傅里叶变换红外光谱（FTIR）进行评估。每种未改性（对照）和 CN 改性材料（测试材料）各制备 10 个试件用于 CS 和 DTS 测试。为了评估氟释放，每个测试和对照材料分别制备了 10 个单独的试件。将获得的结果提交 t 检验（p<0.05）。
CN 增强显著提高了所有 GIC 的机械性能并显著增加了 F 的释放（p<0.05）。CN 增强的 GIC 显示出纳米颗粒的纤维状聚集体分散在基质中。与对照相比，由于 CN 的有机性质，含有 CN 的化合物显示出更高量的 C。通过 FTIR 无法识别在将纳米纤维插入 GIC 时形成的化合物中存在任何化学键差异。
用 CN 改性 GIC 似乎可以产生有前途的修复材料。
