Establishment of treatment that activates oral mesenchymal cells using dental LASER.

建立使用牙科激光激活口腔间充质细胞的治疗方法。

• 批准号: 21791952
• 负责人: MURAKAMI Satoshi
• 金额: $ 2万
• 依托单位: Tokyo Dental College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2010
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21791952/
• 关键词: 象牙質知覚過敏症; 炭酸ガスレーザー; 半導体レーザー; 歯髄細胞; 象牙芽細胞; 炎症性サイトカイン

Aim : The purpose of this study was to investigate pulp responses after CO_2 laser irradiation of the cusp of molar teeth using RT-PCR and immunohistochemical methods.Methods : Adult male Sprague-Dawley rats, weighing about 200 g each, were used in this study. A CO_2 laser was used to irradiate the cusp region of the upper first molar with a total energy of 4 J (Density ; 203.84 J/cm^2). The temperature change in the pulp was measured using a super fine sheath thermocouple.Results : The temperature at the pulp side after the CO_2 laser irradiation increased 22.5℃. The expression of both TNFa and IL-1 mRNAs was significantly higher at 6, 12 and 24 hr (but not at 48 hr) after the laser irradiation compared to the control group (p<0.05). Histologically, a slight degeneration of the pulp tissue was observed immediately after the laser irradiation, and HSP-70 positive cells were observed in the pulp horn immediately after the CO_2 laser irradiation. Cells positive for VEGF were seen in the sub-odontoblast layer immediately and 5 days after the laser irradiation. At 5 days after the laser irradiation, the expression of Nestin was recognized in the deeper pulp cells. NFP-positive nerve fibers had disappeared in the pulp horn by 5 days after the laser irradiation.Conclusions : These results suggest that a low energy of laser irradiation such as used in the clinic to the pulp tissue through the dentin induces the inflammatory and pathological cytokine pathways to repair the damaged pulp tissue.

目的：采用RT-PCR和免疫组织化学方法，探讨CO_2激光照射磨牙牙尖后牙髓的反应。方法：本研究采用成年雄性Sprague-Dawley大鼠，每只体重约200 g。使用CO_2激光照射上第一磨牙牙尖区域，总能量为4 J（密度；203.84 J/cm^2）。采用超细鞘热电偶测量纸浆内温度变化。结果:CO_2激光照射后纸浆侧温度升高22.5℃。与对照组相比，激光照射后 6、12 和 24 小时（但不是 48 小时）TNFa 和 IL-1 mRNA 的表达显着升高（p<0.05）。组织学观察，激光照射后立即观察到牙髓组织轻度变性，CO_2激光照射后立即在牙髓角中观察到HSP-70阳性细胞。激光照射后立即和 5 天后，在成牙本质细胞下层中观察到 VEGF 阳性细胞。激光照射后5天，在较深的牙髓细胞中发现了Nestin的表达。激光照射后5天，牙髓角中的NFP阳性神经纤维已消失。结论：这些结果表明，诸如临床上使用的低能量激光照射通过牙本质对牙髓组织诱导炎症和病理性细胞因子途径来修复受损的牙髓组织。