Rebitski G, Donly K J
Center for Clinical Studies and Department of Pediatric Dentistry, College of Dentistry, University of Iowa.
Am J Dent. 1993 Aug;6(4):204-6.
The purpose of this study was to examine the effect that phosphoric acid etchant, used to remove the smear layer, may have on dentin demineralization inhibition. Fifteen molars had Class V preparations placed on the mesial and distal surfaces, the gingival seat being placed 1 mm below the cementoenamel junction. Randomly, one preparation of each tooth had etchant placed carefully on only enamel for 30 seconds. Etchant was placed on the gingival seat dentin of the remaining preparations, as well as the enamel for 30 seconds. A HEMA dentin primer containing maleic acid was placed and allowed to dry on the unetched dentin, then a Bis-GMA resin with tetrabutyl ammonium tetrafluoroborate was placed. Only the fluoridated resin was placed over the dentin that had been etched. All teeth were then restored with resin composite and subjected to an artificial caries challenge (pH 4.4) for 7 days. Sections 100 microns were obtained, photographed under polarized light microscopy and demineralized areas were digitized. Results demonstrated the mean area (mm2 +/- S.D.) demineralization 0.5 mm from the gingival margin to be: etched dentin (0.77 +/- 0.36); non-etched dentin (1.52 +/- 0.98). A t-test indicated that there was significantly less demineralization when the fluoridated resin came in direct contact with dentin that had the smear layer removed (P < 0.05).
本研究的目的是检验用于去除玷污层的磷酸蚀刻剂对牙本质脱矿抑制的影响。15颗磨牙的近中面和远中面制备V类洞，龈壁位于牙骨质釉质界下方1mm处。随机地，每颗牙的一个洞仅在釉质上小心放置蚀刻剂30秒。蚀刻剂放置在其余洞的龈壁牙本质以及釉质上30秒。在未蚀刻的牙本质上放置含马来酸的HEMA牙本质底漆并让其干燥，然后放置含四丁基四氟硼酸铵的双甲基丙烯酸缩水甘油酯树脂。仅在蚀刻过的牙本质上放置含氟树脂。然后所有牙齿用树脂复合材料修复，并接受人工龋损挑战（pH 4.4）7天。获取100微米厚的切片，在偏光显微镜下拍照，脱矿区域数字化。结果显示从龈缘起0.5mm处脱矿的平均面积（mm2 +/-标准差）为：蚀刻牙本质（0.77 +/- 0.36）；未蚀刻牙本质（1.52 +/- 0.98）。t检验表明当含氟树脂与去除了玷污层的牙本质直接接触时，脱矿明显减少（P < 0.05）。
