Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria.
Division of Orthodontics, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria.
J Mater Sci Mater Med. 2021 Mar 6;32(3):22. doi: 10.1007/s10856-021-06493-y.
The aim of this in vitro study was to evaluate the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation on titanium surface topography and the proliferation and differentiation of osteoblasts using standard clinical treatment settings. Er:YAG laser irradiation at two levels ((1): 160 mJ, pulse at 20 Hz; (2): 80 mJ, pulse at 20 Hz) was applied to moderately rough and smooth titanium disks before MG-63 osteoblast-like cells were cultured on these surfaces. Titanium surface and cell morphology were observed by scanning electron microscopy. Cell proliferation/viability was measured by CCK-8 test. Gene expression of alkaline phosphatase (ALP), osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL), and collagen type 1 was measured by qPCR, and OPG and OC protein production was determined by enzyme-linked immunosorbent assay. Treatment with Er:YAG laser at 160 mJ/20 Hz markedly caused heat-induced fusion of titanium and cell condensation on moderately rough surfaces, but not in smooth surfaces. MG-63 proliferation/viability decreased after 5 days in moderately rough surfaces. The expression of ALP, OC, OPG, and collagen type 1 was unaffected by laser treatment at 160 mJ/20. Laser irradiation at 80 mJ/20 Hz enhanced RANKL gene expression after 5 days in moderately rough surfaces. Study results suggest that Er:YAG laser irradiation at clinically relevant setting has no essential effect on osteogenic gene and protein expression of osteoblasts. However, surface structure, cell attachment, and proliferation are influenced by both treatment protocols, which implies that caution should be taken in the clinical treatment of peri-implant diseases when Er:YAG laser is used.
本体外研究旨在评估铒石榴石激光（Er:YAG）照射对钛表面形貌和使用标准临床治疗设置的成骨细胞增殖和分化的影响。将 Er:YAG 激光以两种水平（(1)：160 mJ，20 Hz 脉冲；(2)：80 mJ，20 Hz 脉冲）照射到中度粗糙和光滑的钛盘上，然后在这些表面上培养 MG-63 成骨样细胞。通过扫描电子显微镜观察钛表面和细胞形态。通过 CCK-8 试验测量细胞增殖/活力。通过 qPCR 测量碱性磷酸酶（ALP）、骨钙素（OC）、骨保护素（OPG）、核因子κB 受体激活剂配体（RANKL）和胶原 1 的基因表达，并通过酶联免疫吸附试验测定 OPG 和 OC 蛋白的产生。160 mJ/20 Hz 的 Er:YAG 激光处理在中度粗糙表面上显著导致钛的热诱导融合和细胞凝聚，但在光滑表面上没有。MG-63 在中度粗糙表面上培养 5 天后增殖/活力下降。激光处理 160 mJ/20 Hz 对 ALP、OC、OPG 和胶原 1 的表达没有影响。80 mJ/20 Hz 的激光照射在中度粗糙表面上 5 天后增强了 RANKL 基因的表达。研究结果表明，在临床相关设置下，Er:YAG 激光照射对成骨细胞的成骨基因和蛋白表达没有本质影响。然而，两种处理方案都会影响表面结构、细胞附着和增殖，这意味着在使用 Er:YAG 激光治疗种植体周围疾病时应谨慎。
