Deposition Mechanism of Inorganic Material in Denture Plaque

1. 义齿牙菌斑和牙结石的观察采用透射电镜和EPMA观察义齿牙菌斑和牙结石的形成过程。在第3天，义齿表面松散结合的微生物之间出现无定形的电子致密物质，尽管在第6小时没有观察到义齿菌斑。患者义齿表面出现层状物质（LS），该物质矿化严重。最初的矿物晶体出现在微生物的质膜、微生物间基质和LS上。这些结果表明，义齿牙菌斑有利于钙的积累，而义齿牙石的形成是由微生物基质、细胞膜和/或牙石引起的。原子力显微镜（SPM-9500）在义齿表面观察中的应用最近推出的原子力显微镜配备图像处理计算机，可以使我们更清晰地三维观察义齿的微小表面结构，如坚固性。通过原子力显微镜与传统扫描电镜对义齿表面的对比观察，评价其观察效果。采用新引入的原子力显微镜，更容易获得更精确的表面粗糙度图像。因此，原子力显微镜是研究观察义齿表面沉积膜、义齿菌斑和义齿牙石等受力的有效设备。

1. Observation of denture plaque and denture calculusThe formation process of the denture plaque and calculus were studied by means of transmission electron microscopy and EPMA.Amorphous electron dense materials appeared in the spaces between the loosely bound microorganisms on the denture surface at 3days, although the denture plaque was not observed at 6 hours. The lamellated substance (LS) appeared on the surface of the denture from the patients, and the substance was heavily mineralized. The initial mineral crystals appeared along the plasma membrane of microorganisms, the intermicrobiol matrix, and the LS.These results suggested that the denture plaque facilitates the calcium accumulation and the formation of the denture calculus is initiated by the interminicrobiol matrix, the cell membrane, and/or the LS.2. Application of Atomic Force Microscope(SPM-9500) to observation of denture surfaceThe recently introduced atomic force microscope can enable us to three-dimensionally observe the minute surface structures of the denture like ruggedness more clearly, being equipped with an image processing computer. Its observation efficacy was evaluated through comparative observations of denture surfaces between an atomic force microscope and a traditional scanning electron microscope.More accurate images of surface ruggedness were more easily obtained by employing the newly introduced atomic force microscope. Therefore , it was concluded that the atomic force microscope is an effective device for research observation of the denture surface deposited with pellicle, denture plaque and denture calculus and so force.