Velasco-Ortega Eugenio, Jiménez-Guerra Alvaro, Ortiz-Garcia Iván, Nuñez-Márquez Enrique, Moreno-Muñoz Jesús, Gil Javier, Delgado Luis M, Rondón-Romero José Luis, Monsalve-Guil Loreto
Comprehensive Dentistry for Adults and Gerodontology, Master in Implant Dentistry, Faculty of Dentistry, University of Seville, Seville, Spain.
Bioengineering Institute of Technology, Universitat Internacional de Catalunya, Barcelona, Spain.
Front Bioeng Biotechnol. 2024 Jan 9;11:1293582. doi: 10.3389/fbioe.2023.1293582. eCollection 2023.
One of the main problems for the long-term behavior of dental implants are loosening of the implant-abutment connection screws and bacterial infiltration. The aim of this work is to increase the screw fixation by silver coating, providing superior mechanical retaining and antibacterial effect. Eighty dental implants with their abutments and screws have been studied. Twenty screws were not coated and were used as a control while the rest of screws were silver coated by sputtering, with three different thickness: 10, 20 and 40 μm and 20 screws per each thickness. Coating morphology and thickness were determined by scanning electron microscopy using image analysis systems. The screws were tightened for each of the thicknesses and the control with two torques 15 Ncm and 20 Ncm and tested under mechanical fatigue simulating oral stresses up to a maximum of 500,000 cycles. The remaining torques at different cycles were determined with a high-sensitivity torquemeter. Cell viability assays were performed with SaOs-2 osteoblasts and microbiological studies were performed against and bacteria strains, determining their metabolic activity and viability using live/dead staining. It was observed a decrease in torque as cycles increase. For a preload of 15 Ncm at 100,000 cycles, the loosening was complete and, for 20 Ncm at 500,000 cycles, 85% of torque was lost. The silver coatings retained the torque, especially the one with a thickness of 40 μm, retaining 90% of the initial torque at 500,000 cycles. It was observed that osteoblastic viability values did not reach 70%, which could indicate a slight cytotoxic effect in contact with cells or tissues; however, the screw should not be in direct contact with tissue or living cells. Silver coating induced a significant reduction of the bacteria metabolic activity for and , around 90% and 85% respectively. Therefore, this coating may be of interest to prevent loosening of implant systems with a worthy antibacterial response.
牙种植体长期使用的主要问题之一是种植体-基台连接螺钉松动和细菌侵入。本研究的目的是通过银涂层增加螺钉固定，提供卓越的机械固位和抗菌效果。对80颗带有基台和螺钉的牙种植体进行了研究。20颗螺钉未涂层，用作对照，其余螺钉通过溅射进行银涂层处理，有三种不同厚度：10μm、20μm和40μm，每种厚度20颗螺钉。使用图像分析系统通过扫描电子显微镜确定涂层形态和厚度。对每种厚度以及对照的螺钉施加15Ncm和20Ncm两种扭矩并拧紧，在模拟口腔应力的机械疲劳下进行测试，最多循环500,000次。使用高灵敏度扭矩计测定不同循环次数下的剩余扭矩。用SaOs-2成骨细胞进行细胞活力测定，针对两种细菌菌株进行微生物学研究，使用活/死染色法确定它们的代谢活性和活力。观察到随着循环次数增加扭矩降低。对于15Ncm的预紧力，在100,000次循环时松动完全，对于20Ncm的预紧力，在500,000次循环时，85%的扭矩丧失。银涂层保持了扭矩，尤其是厚度为40μm的涂层，在500,000次循环时保持了90%的初始扭矩。观察到成骨细胞活力值未达到70%，这可能表明与细胞或组织接触时有轻微的细胞毒性作用；然而，螺钉不应与组织或活细胞直接接触。银涂层使两种细菌的代谢活性显著降低，分别约为90%和85%。因此，这种涂层对于防止具有良好抗菌反应的种植体系统松动可能具有重要意义。
