EXPERIMENTAL STUDY ON THE MECHANISM OF ACQUIRED ACID RESISTANCE OF HUMAN DENTAL ENAMEL BY LASER IRRADIATION

激光照射人牙釉质获得性耐酸性机制的实验研究

基本信息

批准号：
02454472
负责人：
TAGOMORI Shoko
金额：
$ 4.99万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

A possible mechanism of acquired acid resistance of lased enamel was proposed on the basis of the investigations of optical properties, compositional and structural changes and permeability of lased and unlased human dental enamel. Lased enamel showed a high positive birefringence, suggesting the formation of 'microspaces' in enamel. No new products were found, though a decrease of lattice strain and a slight a-axis contraction were recognized in lased enamel compared with unlased enamel. The contents of water, carbonate and organic substances were reduced in lased enamel.On the other hand, the optical properties and permeability of heated enamel and lased enamel after treatment with various solutions were investigated to elucidate the structural changes caused in dental enamel by laser irradiation. Heated enamel at 400ﾟC for 24 hours acquired the highest resistance to acid decalcification and showed a high positive birefringence which was similar to that of lased enamel. Carbolic fuchsin, acidulated phosphate fluoride (APF), and calcifying fluid did not penetrate the heated enamel, though those solutions penetrated the lased enamel well. Gradual changes of birefringence were observed in lased enamel during treatment with acid solutions, and this change was attributed to mineralization of the microspaces in lased enamel.These results suggested that the structural changes in lased enamel are different from those of heated enamel. It appears that lased enamel has micropathways through which solutions can penetrate into the enamel, and also microspaces which could act as sites of deposition for ions released by acid decalcification.

根据对光学性质，成分和结构变化以及LASE和解开的人牙搪瓷的渗透性的研究，提出了一种可能获得的LASE搪瓷酸性的机制。 LASED搪瓷表现出高阳性双折射，表明搪瓷中的“微座”的形成。没有发现新产品，尽管晶格菌株减少了，并且与未升华的搪瓷相比，在LASED搪瓷中识别出轻微的A轴收缩。研究了水，碳酸盐和有机物质的含量，另一方面，研究了用各种溶液处理后的光学特性和加热搪瓷和lase牙釉质的渗透性，以阐明激光照射通过激光照射引起的结构性变化。在400℃的加热搪瓷24小时获得了对酸性脱钙化的最高耐药性，并且表现出高的阳性双向反射，这与Lased搪瓷的脱酸性相似。碳纤维谷素，酸化的磷酸氟化物（APF）和钙化液没有穿透加热的搪瓷，尽管这些溶液渗透了landed的搪瓷。在用酸溶液处理过程中，在LADASE搪瓷中观察到双折射的逐渐变化，并且这种变化归因于Lased搪瓷中微区的矿化。这些结果表明，LASE的搪瓷中的结构变化与加热搪瓷的结构变化不同。似乎LASE的搪瓷具有微孔道，溶液可以通过该道路渗透到牙釉质中，并且可以充当通过酸性脱钙释放的离子的沉积位点。