Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, China.
Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Washington, USA.
J Periodontol. 2021 Aug;92(8):1181-1191. doi: 10.1002/JPER.20-0162. Epub 2020 Sep 10.
Bone augmentation or grafting is often required for placement of dental implants or surgical reconstruction of bony defects. Bioabsorbable magnesium implant was shown to promote osteogenesis in long bones. The objectives of this study were to determine osteogenic effects of pure magnesium (Mg) in rat mandible and underlying mechanisms.
Pure Mg was implanted in sockets after rat mandibular incisors were extracted. Titanium (Ti) was used as control. Systemic effects were determined by serum Mg level and histologic analyses of liver and kidney. Local Mg concentration was measured by microscopy-energy-dispersive spectroscopy (SEM-EDS). Alveolar bone was analyzed by micro-computed tomography (micro-CT) and histology. Osteogenic effects of 0.8 to 20 mM magnesium chloride (MgCl ) on periosteum-derived cells (PDCs) were evaluated by proliferation, alizarin red staining and quantitative RT-PCR assays.
Systemic effects were similar in Mg and Ti groups. Higher local Mg concentration was detected in Mg group (P < 0.05). Micro-CT showed higher alveolar bone volume (2- and 6-weeks post-operation) and denser cancellous bone (2 weeks post-operation) in Mg group, with significant amount of new subperiosteal bone formation on lateral alveolar bone surfaces by H&E staining. In PDC culture, proliferation rates, osteogenic gene expression for runt related transcription factor 2 (Runx2), bone sialoprotein (Bsp) and osteocalcin (Ocn), as well as calcium nodule formation rose significantly in 5, 10, and 20 mM MgCl groups.
Rapid osteogenesis (especially subperiosteal) is induced by pure Mg in rat mandibular alveolar bone. Osteogenic capacity of PDCs is enhanced by higher Mg ion concentrations in vitro.
在植入牙种植体或进行骨缺损的外科重建时，通常需要进行骨增强或移植物。生物可吸收镁植入物已被证明可促进长骨成骨。本研究的目的是确定纯镁（Mg）在大鼠下颌骨中的成骨作用及其潜在机制。
大鼠下颌切牙拔除后，将纯镁植入牙槽窝。钛（Ti）用作对照。通过血清 Mg 水平和肝、肾组织学分析来确定全身效应。通过显微镜-能量色散谱（SEM-EDS）测量局部 Mg 浓度。通过微计算机断层扫描（micro-CT）和组织学分析来分析牙槽骨。通过增殖、茜素红染色和定量 RT-PCR 检测 0.8 至 20mM 氯化镁（MgCl ）对骨膜衍生细胞（PDCs）的成骨作用。
Mg 组和 Ti 组的全身效应相似。Mg 组局部 Mg 浓度较高（P<0.05）。micro-CT 显示 Mg 组术后 2 周和 6 周时牙槽骨体积较高（2 周和 6 周时），松质骨密度较高（术后 2 周），H&E 染色显示外侧牙槽骨表面有大量新的骨膜下骨形成。在 PDC 培养中，5mM、10mM 和 20mM MgCl 组的增殖率、成骨转录因子 2（Runx2）、骨涎蛋白（Bsp）和骨钙素（Ocn）的成骨基因表达以及钙结节形成均显著升高。
纯镁在大鼠下颌牙槽骨中可迅速诱导成骨（特别是骨膜下）。体外较高的 Mg 离子浓度可增强 PDC 的成骨能力。
