应用扫描电镜和电子自旋共振技术分析四环素牙显微结构及其自由基变化

Study on the microstructure and ESR dosimetry of tetracycline-stained teeth with SEM observation and ESR measurement

目的:通过扫描电镜(SEM)和电子自旋共振(ESR)法分析四环素牙的显微结构和ESR信号,并与正常牙进行比较。方法:收集成人正畸需要而拔除的四环素前磨牙和正常前磨牙各10颗。应用扫描电镜观察牙体表面的牙釉质和剖面的牙本质结构,采用X-波段电子自旋共振检测牙体的ESR信号。结果:与正常牙体结构相比,四环素牙的牙釉质结构疏松,釉柱排列不规则;牙本质小管不明显,形态不规则,管间牙本质质地粗糙,结构无序。四环素牙和正常牙相比,其固有的自由基平衡亦有所不同。结论:四环素牙在显微结构和自由基平衡方面和正常牙有显著差别。

PURPOSE：To compare the microstructure and ESR dosimetry between tetracycline-stained teeth and normal teeth by means of scanning electron microscopy（SEM） and electron spin resonance（ESR） dosimeter.METHODS：Ten first or second premolars of tetracycline-stained teeth and ten normal teeth extracted for adult orthodontic persons were collected.The enamel on the surface and the dentine on the cross section of both type of teeth were observed with SEM.The ESR signal of teeth components（enamel and dentine） was evaluated by X-band ESR spectroscopy.RESULTS：Compared with normal teeth,the enamel of tetracycline-stained teeth was of porosity and the enamel prisms were irregular.The dentinal tubules and dentinal matrix also showed obvious difference between the two type of teeth.The X-band ESR spectrum of tetracycline-stained teeth was different from normal teeth.CONCLUSION：The microstructure and the native radicals have significant effect on the tetracyclines deposited in the teeth.