Printzell Lisa, Reseland Janne E, Edin Nina F J, Ellingsen Jan E
Department of Prosthodontics, Faculty for Dentistry, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway.
Department of Biomaterials, Faculty for Dentistry, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway.
Eur J Oral Sci. 2019 Dec;127(6):500-507. doi: 10.1111/eos.12654. Epub 2019 Jul 19.
Radiotherapy to the head and neck region negatively influences the osseointegration and survival of dental implants. The effects of cobalt 60 ( Co) ionizing radiation and the impact of backscatter rays were investigated on human mesenchymal stem cells cultured on titanium surfaces. Bone marrow-derived human mesenchymal stem cells were seeded on titanium (Ti), fluoride-modified titanium (TiF), and tissue culture plastic. Cells were exposed to ionizing γ-radiation in single doses of 2, 6, or 10 Gy using a Co source. Density and distribution of cells were evaluated using confocal laser-scanning microscopy, 21 d post-irradiation. Lactate dehydrogenase concentration and the levels of total protein and cytokines/chemokines were measured in the cell-culture medium on days 1, 3, 7, 14, and 21 post-irradiation. Unirradiated cells were used as the control. Irradiation had no effect on cell viability, collagen and actin expression, or cell distribution, but induced an initial increase in the secretion of interleukin (IL)-6, IL-8, monocyte chemotactic protein 1 (MCP-1), and vascular endothelial growth factor (VEGF), followed by a decrease in secretion after 3 or 7 d. Irradiation resulted in secretion of a lower amount of all analytes examined compared with controls on day 21, irrespective of radiation dose and growth surface. Backscattering from titanium did not influence the cell response significantly, suggesting a clinical potential for achieving successful osseointegration of dental implants placed before radiotherapy.
头颈部放疗会对牙种植体的骨结合及存活产生负面影响。研究了钴60（Co）电离辐射及反向散射射线对在钛表面培养的人间充质干细胞的影响。将骨髓来源的人间充质干细胞接种于钛（Ti）、氟改性钛（TiF）及组织培养塑料上。使用钴源以2、6或10 Gy的单剂量对细胞进行电离γ辐射。照射后21天，使用共聚焦激光扫描显微镜评估细胞的密度和分布。在照射后第1、3、7、14和21天，测量细胞培养基中的乳酸脱氢酶浓度、总蛋白水平以及细胞因子/趋化因子水平。未照射的细胞用作对照。照射对细胞活力、胶原蛋白和肌动蛋白表达或细胞分布没有影响，但会导致白细胞介素（IL）-6、IL-8、单核细胞趋化蛋白1（MCP-1）和血管内皮生长因子（VEGF）分泌最初增加，随后在3或7天后分泌减少。与对照组相比，照射后第21天所有检测分析物的分泌量均较低，且与辐射剂量和生长表面无关。钛的反向散射对细胞反应没有显著影响，这表明在放疗前植入牙种植体实现成功骨结合具有临床潜力。
