Wright J T, Chen S C, Hall K I, Yamauchi M, Bawden J W
Department of Pediatric Dentistry, School of Dentistry University of North Carolina at Chapel Hill 27599-7450, USA.
J Dent Res. 1996 Dec;75(12):1936-41. doi: 10.1177/00220345960750120401.
Despite extensive investigation, the development mechanism or mechanisms resulting in dental fluorosis are unknown. Several hypotheses suggest abnormal matrix synthesis, secretion, and delayed and/or defective matrix degradation with retention of enamel protein. The purpose of this study was to characterize the protein composition of fluorosed human enamel. Nine permanent moderately fluorosed (developed in a 3.2 ppm H2O area) and ten permanent normal control teeth (from individuals with < 0.2 ppm F in their drinking water) were evaluated. The enamel fluoride concentration, protein content, and amino acid composition were determined for each tooth. The enamel proteins were further characterized by gel electrophoresis and by Western blot analysis by means of polyclonal antibodies raised against recombinant amelogenin protein. Fluorotic enamel had significantly elevated (p = 0.0001) F levels compared with normal enamel (mean [F-] fluorosed = 431 ppm; mean [F-] control = 62 ppm). While there was a significantly greater protein content by weight in fluorosed enamel compared with normal enamel (mean fluorosed = 0.27%; mean control = 0.11%), the amino acid profiles were similar for fluorosed and normal enamel. Gel electrophoresis showed fluorosed enamel to have a greater diversity of primarily low-molecular-weight proteins compared with normal enamel. Western blot analysis did not indicate retention of amelogenin in either fluorosed or normal enamel. This investigation showed that the protein content of fluorosed enamel was greater than that of normal enamel; however, the amino acid compositions were similar for fluorosed and normal enamel. Furthermore, there does not appear to be retention of significant amounts of amelogenin in fully mature, moderately fluorosed human enamel. Although delayed removal of the enamel matrix proteins may play a role in the hypomineralization defects seen in fluorosed enamel, the majority of these proteins are absent in the mature tissue of these moderately fluorosed teeth.
尽管进行了广泛的研究，但导致氟斑牙的一种或多种发育机制仍不清楚。有几种假说认为，其机制是基质合成和分泌异常，以及釉质蛋白滞留导致基质降解延迟和/或存在缺陷。本研究的目的是对氟斑牙釉质的蛋白质组成进行表征。评估了9颗永久性中度氟斑牙（在水氟含量为3.2 ppm的地区形成）和10颗永久性正常对照牙（来自饮用水氟含量<0.2 ppm的个体）。测定了每颗牙齿的釉质氟浓度、蛋白质含量和氨基酸组成。通过凝胶电泳和使用针对重组釉原蛋白产生的多克隆抗体进行蛋白质印迹分析，对釉质蛋白进行了进一步表征。与正常釉质相比，氟斑牙釉质的氟水平显著升高（p = 0.0001）（氟斑牙的平均[F-] = 431 ppm；对照的平均[F-] = 62 ppm）。虽然与正常釉质相比，氟斑牙釉质的蛋白质重量含量显著更高（氟斑牙的平均含量 = 0.27%；对照的平均含量 = 0.11%），但氟斑牙釉质和正常釉质的氨基酸谱相似。凝胶电泳显示，与正常釉质相比，氟斑牙釉质主要是低分子量蛋白质的多样性更大。蛋白质印迹分析未表明氟斑牙釉质或正常釉质中存在釉原蛋白滞留。这项研究表明，氟斑牙釉质的蛋白质含量高于正常釉质；然而，氟斑牙釉质和正常釉质的氨基酸组成相似。此外，在完全成熟的中度氟斑牙釉质中似乎不存在大量釉原蛋白的滞留。虽然釉质基质蛋白的延迟去除可能在氟斑牙釉质中出现的矿化不足缺陷中起作用，但在这些中度氟斑牙的成熟组织中，这些蛋白中的大多数并不存在。
