人类牙列放射防护模具的防护性能分析

Preliminary Study on the Performance of Human Dental Radiation Protection Mold

目的建立人类牙列放射防护模具模型,研究不同厚度、材质的防护模具对高能X射线(6 MV)的阻射效能,为后续研究提供实验基础。方法将厚度为1 mm的铅片裁剪成2 cm×10 cm的薄片,弯制成标准牙弓形状,将加成型硅橡胶按1∶1混合均匀后包埋铅片,两侧厚度分别为1、3和5 mm,设为实验组。用加成型硅橡胶制成2 cm×10 cm,厚度分别为3、7和11 mm的薄片,弯制成标准牙弓形状,设为对照组。将离体第三磨牙包埋于石膏模型上,在各组模具防护下,采用6 MV能量的X射线,以1 Gy/次的剂量照射,测量离体牙上X射线的剂量。结果实验组的阻隔效率明显高于对照组,差别有统计学意义(P<0.001);对照组的阻隔效率随硅橡胶厚度增加而增加,差别有统计学意义(P<0.001);实验组的阻隔效率随硅橡胶厚度增加而减小,差别有统计学意义(P=0.023)。结论硅橡胶厚度对阻隔效率有一定影响。以硅橡胶包埋铅片设计防护模具可作为研究基础。需在后续研究中进一步优化调整铅与硅橡胶的厚度和比例。

Objective A model was established to study the resistance efficiency of high-energy X-ray(6 MV)of different thickness and specifications,and provide the experimental basis for later clinical experiments.Methods A 2 cm×10 cm lead sheet was cut from the lead sheet with a thickness of 1 mm,and shaped into a standard arch form then embedded in silicone rubber,mixed 1∶1.The silicone rubber has a thickness of 1 mm on both sides for one set,3 mm for another set,and 5 mm for a third set,all of which were designed as the experimental groups.The control group consisted of arches made from 2 cm×10 cm lead sheets with thickness of 3,7,and 11 mm.These lead arches were also embedded in silicone rubber and shaped into standard dental arch forms.The isolated third molar was embedded on the plaster model and the residual amount of X lines was measured with 6 MV energy X-rays at a dose of 1 Gy/times.Results The barrier efficiency of the experimental group was significantly higher than that of the control group,and the difference was statistically significant(P<0.001);The barrier efficiency of the control group was increased with the increase of the silicone rubber thickness,and the difference was statistically significant(P<0.001);The experimental group was reduced with the increase of the silicone rubber thickness,and the difference was statistically significant(P=0.023).Conclusion The silicone rubber thickness has some influence on the barrier efficiency.It is feasible to design the protective mold with silicone rubber embedded lead sheet.Further optimization and adjustment of the thickness and proportion of lead sheet and silicone rubber are needed in subsequent research.