Dragolich W E, Pashley D H, Brennan W A, O'Neal R B, Horner J A, Van Dyke T E
U.S. Army, Ft. Bliss, TX.
J Periodontol. 1993 Nov;64(11):1045-51. doi: 10.1902/jop.1993.64.11.1045.
This study examined ferric oxalate's ability to occlude dentinal tubules both in the presence of a smear layer and after its removal. Radicular dentinal chips were prepared with a smear layer created from a high speed carbide bur. The dentinal chips were then grouped as follows: 1) those with the smear layer remaining intact; 2) those sonicated for 7 minutes; 3) those treated with 10% tetracycline HCl; 4) those treated with 0.5M EDTA; 5) those treated with 20% citric acid; or 6) those treated with saturated citric acid. Six percent ferric oxalate was applied for 1 minute to the dentinal chips under blinded conditions. The chips were examined under SEM and the number of small and large crystals formed were counted. The results indicate that a decrease in the number of small crystals occurs following pretreatment of the smear layer by chemical means. An increased variability in size and shape of the crystals is also observed when no chemical pretreatment is used. Thus, relative to the number of crystals that form, no chemical pretreatment of radicular dentin is indicated prior to application of ferric oxalate in the treatment of root sensitivity.
本研究考察了草酸铁在有玷污层存在时以及去除玷污层后封闭牙本质小管的能力。用高速硬质合金车针制备带有玷污层的牙根牙本质碎屑。然后将牙本质碎屑分组如下：1）玷污层保持完整的；2）超声处理7分钟的；3）用10%盐酸四环素处理的；4）用0.5M乙二胺四乙酸处理的；5）用20%柠檬酸处理的；或6）用饱和柠檬酸处理的。在盲法条件下，将6%的草酸铁应用于牙本质碎屑1分钟。在扫描电子显微镜下检查碎屑，并计数形成的小晶体和大晶体的数量。结果表明，通过化学方法对玷污层进行预处理后，小晶体数量减少。当不进行化学预处理时，还观察到晶体的大小和形状变异性增加。因此，相对于形成的晶体数量，在应用草酸铁治疗牙根敏感之前，未表明对牙根牙本质进行化学预处理。
