AFM and CFM Study of the Etiology of Fluorosis

产品说明：无论采用何种治疗模式，如果氟的全身副作用能够减少，氟作为牙科预防剂和公共卫生措施的有效性将会增加。饮用水中氟化物的最佳水平为1 ppm，因为它可以减少30-50%的龋齿，而不会相应增加氟斑牙，尽管人们知道超过1 ppm的水平会带来更大的龋齿减少。氟中毒的生物学病因尚不清楚，尽管其中一个建议的机制是釉质基质蛋白从釉质表面的去除受损，这阻碍了晶体生长，导致釉质发育不全缺陷。本原子力显微镜和化学力显微镜研究（AFM和CFM）将描述和比较氟斑牙和非氟斑牙釉质晶体的结合能力，以及表征釉质蛋白，釉原蛋白，成釉蛋白，釉蛋白，和他们的裂解产物。最近的研究已经确定了釉质晶体表面上的电荷域，其似乎影响蛋白质晶体与釉质表面的结合。使用从釉质发育的各个阶段（分泌、过渡和成熟）获得的釉质晶体将有助于确定何时电荷域出现在晶体表面上以及何时氟化物对釉质矿化具有主要影响。将氟斑牙和非氟斑牙釉质晶体两者的蛋白质结合能力与从晶体剥离这些蛋白质所需的磷酸盐溶液的浓度相关联并进行比较。将通过CFM使用不同的化学改性尖端（“功能化尖端”）检查晶体表面上电荷域的存在。将研究蛋白质/晶体表面相互作用中的电荷域的作用。精细表征的蛋白质及其切割产物可能有助于鉴定参与晶体结合的蛋白质基序。这些蛋白质对晶体生长的影响也将在AFM中进行检查。单晶生长已经在AFM中测量。 在本研究中将进行类似的生长测量，即，在晶体长度和宽度方面;也将评估凹坑或小丘形成。本项目的结果不仅将阐明釉基质蛋白在釉质矿化中的作用，而且还将为氟中毒的病因提供解释。这一解释可能允许设计治疗或治疗方法，以防止氟化物的有害作用，并使其以导致龋齿更大程度减少的水平施用。

DESCRIPTION: The effectiveness of fluoride as a Dental preventive agent and public health measure would be increased if the systemic side effects of fluoride could be reduced, no matter what the mode of therapy. The optimal level of fluoride l ppm in drinking water has been established because it gives a reduction of caries of 30-50% without the corresponding increase in Dental fluorosis, although it is known that levels exceeding l ppm would bring about greater reductions in caries. The biological etiology of fluorosis is not understood, although one of the suggested mechanisms is the impaired removal of enamel matrix proteins from enamel surfaces, which impede crystal growth, leading to hypoplastic defects in enamel. This atomic and chemical force microscopy study (AFM and CFM) will describe and compare the binding capacity of fluorotic and non-fluorotic enamel crystals for the well characterized enamel proteins, amelogenin, ameloblastin, enamelin, and their cleavage products. Recent studies have identified charge domains on the enamel crystal surfaces, which appear to affect protein crystal binding to the enamel surfaces. The use of enamel crystals obtained from various stages (secretory, transition and maturation) of enamel development will help identify when charge domains appear on crystal surfaces and when fluoride has major effect on enamel mineralization. Protein binding capacity of both the fluorotic and non-fluorotic enamel crystals will be correlated and compared with the concentration of a phosphate solution needed to strip these proteins from the crystals. The presence of charge domains on the crystal surfaces will be examined by CFM using different chemically modified tips ("functionalized tips"). The role of the charge domains in protein/crystal surface interactions will be investigated. The exquisitely characterized proteins and their cleavage products may help identify the protein motifs involved in the crystal binding. The effect of these proteins on crystal growth will also be examined in the AFM. Single crystal growth has already measured in the AFM. Similar growth measurements will be made in this study, i.e., in crystal length and width; pit or hillock formation will also be assessed. The outcome of this project will not only shed light on the role the enamel matrix proteins play in enamel mineralization, but also offer an explanation for the cause of fluorosis. This explanation may allow therapies or treatments to be devised that will prevent the deleterious effects of fluoride and let it be administered at levels, which will cause a greater reduction in caries.