Alhussein Abdullah, Alsahafi Rashed, Balhaddad Abdulrahman A, Mokeem Lamia, Schneider Abraham, Jabra-Rizk Mary-Ann, Masri Radi, Hack Gary D, Oates Thomas W, Sun Jirun, Weir Michael D, Xu Hockin H K
PhD Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA.
Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh 11451, Saudi Arabia.
Bioengineering (Basel). 2023 Aug 22;10(9):991. doi: 10.3390/bioengineering10090991.
Composites are commonly used for tooth restorations, but recurrent caries often lead to restoration failures due to polymerization shrinkage-stress-induced marginal leakage. The aims of this research were to: (1) develop novel low-shrinkage-stress (L.S.S.) nanocomposites containing dimethylaminododecyl methacrylate (DMADDM) with nanoparticles of calcium fluoride (nCaF) or amorphous calcium phosphate (NACP) for remineralization; (2) investigate antibacterial and cytocompatibility properties.
Nanocomposites were made by mixing triethylene glycol divinylbenzyl ether with urethane dimethacrylate containing 3% DMADDM, 20% nCaF, and 20% NACP. Flexural strength, elastic modulus, antibacterial properties against biofilms, and cytotoxicity against human gingival fibroblasts and dental pulp stem cells were tested.
Nanocomposites with DMADDM and nCaF or NACP had flexural strengths matching commercial composite control without bioactivity. The new nanocomposite provided potent antibacterial properties, reducing biofilm CFU by 6 logs, and reducing lactic acid synthesis and metabolic function of biofilms by 90%, compared to controls ( < 0.05). The new nanocomposites produced excellent cell viability matching commercial control ( > 0.05).
Bioactive L.S.S. antibacterial nanocomposites with nCaF and NACP had excellent bioactivity without compromising mechanical and cytocompatible properties. The new nanocomposites are promising for a wide range of dental restorations by improving marginal integrity by reducing shrinkage stress, defending tooth structures, and minimizing cariogenic biofilms.
复合材料常用于牙齿修复，但由于聚合收缩应力引起的边缘渗漏，继发龋常导致修复失败。本研究的目的是：（1）开发新型低收缩应力（L.S.S.）纳米复合材料，其包含甲基丙烯酸二甲氨基十二烷基酯（DMADDM）以及用于再矿化的氟化钙纳米颗粒（nCaF）或无定形磷酸钙（NACP）；（2）研究抗菌和细胞相容性。
通过将三甘醇二乙烯基苄基醚与含有3% DMADDM、20% nCaF和20% NACP的聚氨酯二甲基丙烯酸酯混合来制备纳米复合材料。测试了弯曲强度、弹性模量、对生物膜的抗菌性能以及对人牙龈成纤维细胞和牙髓干细胞的细胞毒性。
含有DMADDM和nCaF或NACP的纳米复合材料的弯曲强度与无生物活性的市售复合对照材料相当。与对照相比，新型纳米复合材料具有强大的抗菌性能，使生物膜的菌落形成单位减少6个对数，并使生物膜的乳酸合成和代谢功能降低90%（P<0.05）。新型纳米复合材料产生了与市售对照相当的优异细胞活力（P>0.05）。
含有nCaF和NACP的具有生物活性的L.S.S.抗菌纳米复合材料具有优异的生物活性，同时不影响机械性能和细胞相容性。新型纳米复合材料通过降低收缩应力改善边缘完整性、保护牙齿结构并使致龋生物膜最小化，有望用于广泛的牙齿修复。
