Benjakul Sutiwa, Jitpukdeebodintra Suwanna, Leethanakul Chidchanok
Orthodontic Section, Department of Preventive Dentistry, Faculty of Dentistry, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
Department of Oral Biology, Faculty of Dentistry, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
Eur J Orthod. 2018 Jul 27;40(4):356-363. doi: 10.1093/ejo/cjx062.
Vibration can be used to accelerate tooth movement, though the exact mechanisms remain unclear. This study aimed to investigate the effects of low magnitude high frequency (LMHF) vibration combined with compressive force on periodontal ligament (PDL) cells in vitro.
Human PDL cells were isolated from extracted premolar teeth of four individuals. To determine the optimal frequency for later used in combination with compressive force, three cycles of low-magnitude (0.3 g) vibrations at various frequencies (30, 60, or 90 Hz) were applied to PDL cells for 20 min every 24 h. To investigate the effects of vibration combined with compressive force, PDL cells were subjected to three cycles of optimal vibration frequency (V) or 1.5 g/cm2 compressive force for 48 h (C) or vibration combined with compressive force (VC). Cell viability was assessed using MTT assay. PGE2, soluble RANKL (sRANKL), and OPG production were quantified by ELISA. RANKL, OPG, and Runx2 expression were determined using real-time PCR.
Cell viability was decreased in groups C and VC. PGE2 and RANKL, but not OPG, were increased in groups V, C, and VC, thus increasing the RANKL/OPG ratio. The highest level was observed in group VC. sRANKL was increased in groups V, C, and VC; however, no significant different between the experimental groups. Runx2 expression was reduced in groups C and VC.
Vibration increased PGE2, RANKL, and sRANKL, but not OPG and Runx2. Vibration had the additive effects on PGE2 and RANKL, but not sRANKL in compressed PDL cells.
振动可用于加速牙齿移动，但其确切机制尚不清楚。本研究旨在探讨低频高强度（LMHF）振动联合压力对体外牙周膜（PDL）细胞的影响。
从4名个体拔除的前磨牙中分离出人PDL细胞。为确定后续与压力联合使用的最佳频率，每24小时对PDL细胞施加3个周期、不同频率（30、60或90Hz）、低强度（0.3g）的振动，持续20分钟。为研究振动联合压力的影响，将PDL细胞分别进行3个周期的最佳振动频率（V）处理、1.5g/cm²压力处理48小时（C）或振动联合压力处理（VC）。采用MTT法评估细胞活力。通过ELISA定量检测前列腺素E2（PGE2）、可溶性核因子κB受体活化因子配体（sRANKL）和骨保护素（OPG）的产生。使用实时PCR测定RANKL、OPG和Runx2的表达。
C组和VC组细胞活力降低。V组、C组和VC组中PGE2和RANKL升高，但OPG未升高，从而使RANKL/OPG比值增加。VC组中该比值最高。V组、C组和VC组中sRANKL升高；然而，各实验组之间无显著差异。C组和VC组中Runx2表达降低。
振动增加了PGE2、RANKL和sRANKL，但未增加OPG和Runx2。在受压的PDL细胞中，振动对PGE2和RANKL有叠加作用，但对sRANKL没有。
