放射线对牙体硬组织及其抗酸溶解性影响的研究

目的　观测离体牙釉质、牙本质在照射放射线后的结构、胶原及抗酸溶解性的变化 ,探讨放射性龋发生的可能机制。方法　 5 6颗牙牙冠的牙釉质标本及 6 3颗牙牙根的牙本质标本分别经30、5 0、70Gy放射线照射后用SEM观察釉质及牙本质的结构、用组化方法观察牙本质胶原的变化、用人工龋实验观察对其抗酸溶解性的影响。结果　不同剂量的放射线照射后均可改变釉质的形貌 ,降低釉质的抗酸溶解性 ,各实验组间未见明显差别 ;5 0、70Gy组照射后可改变牙本质的形貌、牙本质胶原溶解性 ,降低牙本质的抗酸溶解性 ,30Gy组对牙本质的改变与对照组相似。 结论　放射线照射后牙釉质和牙本质的结构和某些成分都会发生一定程度的破坏 ,这可能是导致放射性龋的原因之一。

Effect of irradiation on tooth hard tissue and its resistance to acid

Objective To study the effect of irradiation on the susceptibility of radiation caries Methods The structures of 56 teeth enamel and dentin of 63 roots were observed using SEM and the collagen fibre and the resistance to the acid were also investigated after irradiation of 30 Gy, 50 Gy and 70 Gy .Results The enamel structure changes were found after irradiation with different doses The significant difference was found in the enamel changes between high or middle dose group and low dose group or control The dentin morphology changed,some collagen fibre vanished and resistance to acid was reduced after irradiation with 50 Gy and 70 Gy Conclusions The radiation reduced the resistance of teeth to the acid and increased the caries susceptibility