Iijima Y, Ruben J L, Zuidgeest T G, Arends J
Nagasaki University, Japan.
Caries Res. 1993;27(2):106-10. doi: 10.1159/000261526.
In this paper the acid resistance of hyper-remineralized dentine was quantified by means of fluoride and mineral measurements. Hyper-remineralization was achieved by demineralization of dentine in an acidic gel system (pH 5) for 3 weeks, followed by remineralization in a solution containing 1.5 mM Ca, 0.9 mM phosphate and 10 ppm F at pH 7 and 37 degrees C for 8 days. The samples were subsequently again demineralized in the gel system mentioned for 1, 2 and 3 weeks. Analysis for fluoride was done by means of the microdrill biopsy technique and to obtain information on the fluoride distribution by secondary ion mass spectrometry (SIMS); mineral was assessed by microradiography. The results showed that in hyper-remineralized dentine the original fluoride content was approximately 30,000 ppm F. This value was still in the same order after the acid challenge of 3 weeks at pH 5. These values were substantially higher than the baseline values in sound or in demineralized dentine being about 900 ppm F. The main microradiographic result was that there was no significant mineral change in the hyper-remineralized dentine due to the acid challenges. There was, however, a tendency for mineral redistribution deeper into the dentine lesion leading to lamination phenomena. The SIMS experiments on some of the samples showed a fluoride distribution in agreement with the microdrill fluoride data. Furthermore a fluoride redistribution took place in deeper parts of the lesion due to the acid challenges. The combined fluoride concentration and microradiographical data indicate that fluoride-enriched and highly mineralized hyper-remineralized dentine is more acid resistant than sound or demineralized dentine.
在本文中，通过氟化物和矿物质测量对过度再矿化牙本质的耐酸性进行了量化。通过在酸性凝胶体系（pH 5）中对牙本质进行脱矿3周来实现过度再矿化，随后在含有1.5 mM钙、0.9 mM磷酸盐和10 ppm氟、pH 7且温度为37℃的溶液中再矿化8天。随后将样品再次在上述凝胶体系中脱矿1、2和3周。通过微钻活检技术进行氟化物分析，并通过二次离子质谱（SIMS）获取氟化物分布信息；通过显微放射照相术评估矿物质。结果表明，在过度再矿化牙本质中，原始氟含量约为30,000 ppm F。在pH 5下进行3周的酸蚀挑战后，该值仍处于同一水平。这些值显著高于健康或脱矿牙本质中的基线值，约为900 ppm F。显微放射照相的主要结果是，过度再矿化牙本质由于酸蚀挑战没有明显的矿物质变化。然而，存在矿物质向牙本质病变更深层重新分布的趋势，导致分层现象。对一些样品进行的SIMS实验显示氟化物分布与微钻氟化物数据一致。此外，由于酸蚀挑战，在病变更深部位发生了氟化物重新分布。氟化物浓度和显微放射照相数据相结合表明，富含氟且高度矿化的过度再矿化牙本质比健康或脱矿牙本质更耐酸。
