Huang Tsui-Hsien, Liu Shiau-Lee, Chen Chih-Lin, Shie Ming-You, Kao Chia-Tze
Dental Department, Chung Shan Medical University Hospital. School of Dentistry, College of Oral Medicine, Chung Shan Medical University Taichung, Taiwan.
Photomed Laser Surg. 2013 Feb;31(2):72-7. doi: 10.1089/pho.2012.3359. Epub 2013 Jan 17.
The purpose of this study was to analyze proliferation, inflammation, and osteogenic effects on periodontal ligament (PDL) cells after low-level laser therapy (LLLT) under simulated orthodontic tension conditions.
Low-level lasers affect fibroblast proliferation and collagen synthesis and reduce inflammation. Few studies have focused on the LLLT changes in the PDL caused by moving teeth.
A human PDL cell line was cultured in a -100 kPa tension incubator. The PDL cells were treated with a 670 nm low-level diode laser, output power of 500 mW (continuous wave modus) for 2.5 or 5 sec, spot area 0.25 cm(2), corresponding to 1.25 and 2.5 J at an energy density of 5 or 10 J/cm(2), respectively. PDL cell viability was assayed by detecting the ability of the cells to cleave tetrazolium salt to formazan dye. Inflammation and osteogenic markers were analyzed by Western blot analysis.
PDL cell viablity increased in the experimental group, based on the ability of the cells to cleave tetrazolium salt at day 7 (p<0.05). The experimental group showed no difference in PDL cellular morphology compared with the control group. The inflammation markers inducible NO synthase (iNOS), cyclooxygenase (COX)-2 and interleukin (IL)-1 showed stronger expression in 5 and 10 J/cm(2) therapy at days 1 and 5, but decreased in expression at day 7. The osteogenic marker osteocalcin (OC) expression level was significantly higher at day 7 (p<0.05) than in the control cells.
LLLT significantly increased PDL cell proliferation, decreased PDL cell inflammation, and increased PDL OC activity under the tension conditions used in this study.
本研究旨在分析模拟正畸张力条件下低强度激光治疗（LLLT）对牙周膜（PDL）细胞的增殖、炎症和成骨作用。
低强度激光可影响成纤维细胞增殖和胶原蛋白合成，并减轻炎症。很少有研究关注牙齿移动引起的牙周膜中低强度激光治疗的变化。
将人牙周膜细胞系培养于-100kPa张力培养箱中。用670nm低强度二极管激光处理牙周膜细胞，输出功率500mW（连续波模式），照射2.5或5秒，光斑面积0.25cm²，能量密度分别为5或10J/cm²时对应的能量为1.25和2.5J。通过检测细胞裂解四氮唑盐形成甲臜染料的能力来测定牙周膜细胞活力。通过蛋白质免疫印迹分析来分析炎症和成骨标志物。
基于细胞在第7天裂解四氮唑盐的能力，实验组牙周膜细胞活力增加（p<0.05）。与对照组相比，实验组牙周膜细胞形态无差异。炎症标志物诱导型一氧化氮合酶（iNOS）、环氧化酶（COX）-2和白细胞介素（IL）-1在第1天和第5天的5和10J/cm²治疗中表达较强，但在第7天表达下降。成骨标志物骨钙素（OC）的表达水平在第7天显著高于对照细胞（p<0.05）。
在本研究使用的张力条件下，低强度激光治疗显著增加了牙周膜细胞增殖，降低了牙周膜细胞炎症，并增加了牙周膜骨钙素活性。
