脉冲CO_2激光照射对牙髓细胞影响的实验研究

Influence of Pulse CO_2 Laser Irradiation on Dental Pulp

目的动态观察脉冲CO_2激光照射大鼠磨牙后牙髓组织中多种细胞因子在不同时间段和部位的表达,探讨热损伤后牙髓的防御和自我修复机制。方法采用免疫组织化学染色方法观测能量密度为10.5 J/mm^2的脉冲CO_2激光照射牙本质过敏症模型大鼠磨牙冠部牙髓组织中热休克蛋白70(HSP-70)、转化生长因子β_1(TGF-β_1)和骨形成蛋白2(BMP-2)在照射后第4小时,3d,2和4周时的表达,并对其进行定量分析。结果HSP-70、TGF-β_1、BMP-2分别在照射后第4小时、2和4周表达最强,与其余各时问段的表达差异有显著意义。结论HSP-70、TGF-β_1和BMP-2在损伤早期起防御作用,后期参与牙髓的自我修复过程,并促进修复性牙本质的形成。

Objective To observe dynamically the expression of several cell factors at different periods and regions in rat＇s dental pulp （RDP） of animal model of dentine hypersensitivity （DH） irradiated by pulse CO2 laser irradiation. Methods The expression of HSP-70, TGF-β1 and BMP-2 at four hours, 3 days, 2 weeks and 4 weeks was checked by immunohistochemical methods in coronal dental pulp tissue after laser irradiation. Results HSP-70 expression state at four hours subgroup, TGF-β1 expression state at 2 weeks subgroup and BMP-2 expression state at 4 weeks subgroup had statistical difference with other subgroups respectively. Conclusions RDP undergoes reversible inflammation changes after laser irradiation at the dose of 10. 5 J/mm^2 which can be used safely. HSP-70 arises specially when RDP received heat stimulation. TGF-β1 and BMP-2 are presented in normal or impaired RDP. The dynamic changes of expression showed that the two factors defend RDP in the early period, then participate in the self-reparative process and promote the formation of reparative dentin.