Search of evidence on the effect with dental resin curing light irradiation against dental pulp

牙科树脂固化光已用于树脂基复合充填牙的修复和牙齿漂白治疗。然而，它对口腔组织如牙髓或口腔粘膜的影响也没有得到较少的考虑。本研究的目的是探讨牙科树脂固化后的光照射对牙髓的影响。用丙二醛测定发现，树脂固化蓝光照射可增加大鼠离体主动脉血管的脂质过氧化水平。并呈时间依赖性地抑制细胞增殖活性，诱导人主动脉血管平滑肌细胞(VSMC)凋亡。因此，这些结果表明蓝光照射下VSMC产生了过氧化氢和羟基自由基等活性氧物种，并诱导了与氧化应激相关的细胞毒作用，从而加剧了脂质过氧化和细胞凋亡。此外，N-乙酰-L-半胱氨酸是典型的细胞内抗氧化剂，可保护血管平滑肌细胞免受氧化应激所致的细胞毒性作用。

Dental resin curing light has been used to restore of tooth with resin-based composite fillings and to treat of tooth bleaching. However, it has not been less considered the effect on the oral tissues such as dental pulp or oral mucosa. The aim of this study was to investigate whether dental resin curing light irradiation is affected on the dental pulp. We found that irradiation of resin curing blue light was increased the level of lipid peroxidation on isolated rat aorta blood vessels to use the measurement of malondialdehyde. Furthermore, it was decreased the cell proliferation activity in time-dependent manner and was induced the apoptosis of human aorta vascular smooth muscle cells(VSMC). Therefore, these results indicated that reactive oxygen species such as hydrogen peroxide and hydroxyl radical were generated in VSMC by blue light irradiation, and they were induced the cytotoxicity associated with oxidative stress which was increased the lipid peroxidation and apoptosis. In addition, N-acetyl-L-cysteine which is typical intracellular antioxidants prevented VSMC from cytotoxicity associated with oxidative stress.