Preparation of thin ceramic monofilaments for TEM observation with novel embedding processes.

An applicable method to prepare transmission electron microscopy specimens from ceramic fibers for longitudinal and cross-sectional observations is investigated. The method includes novel embedding processes to fix fibers, a polishing process using a self-manufactured device to get uniformly low thickness (40 μm for L-fiber, 60 μm for C-fiber), a one-side dimpling process to grind the specimen to near electron transparency (about 5 μm in thickness for both L-fiber and C-fiber) and an efficient ion milling process using calculated parameters. These techniques are reliable to accomplish the preparation with high quality in a relatively short time.

Kinetic model for hydroxyapatite precipitation on human enamel surface by electrolytic deposition.

The electrolytic deposition (ELD) of hydroxyapatite (HAP) coating on human enamel surface for different loading times at varied temperatures (ranging from 37 degrees C to 85 degrees C) and varied current densities (ranging from 0.05 mA cm(-2) to 10 mA cm(-2)) was investigated in this study. Thin film x-ray diffraction, Fourier transform infrared and micro-Raman spectra analysis, as well as an environmental scanning electron microscope, were used to characterize the coating.

In situ study on the curing process of calcium phosphate bone cement.

The aim of this study was to follow the entire curing process of modified alpha-TCP cement, and to explore how the liquid phase affects the curing reaction. Two calcium phosphate bone cements (CPCs) with a variety of aqueous solution were studied for comparison. In situ X-ray diffraction analysis and pH testing were employed to follow the chemical reaction, while quantitative ultrasonic measurement (QUS) was carried out to monitor the physical change.

In situ tracing the process of human enamel demineralization by electrochemical impedance spectroscopy (EIS).

Objective: The purpose of this study was to in situ characterize the demineralization (namely dissolution of hydroxyapatite) on the surface of the human enamel using electrochemical impedance spectroscopy (EIS) technology.

Methods: Fresh human third molars extracted without visible evidence of caries, were used in this study. After they were immersed in a demineralizing solution prepared from lactic acid and carboxy methyl cellulose sodium (Na-CMC) buffering at pH 4, demineralization happened on their surfaces.

Piezoelectric properties of human dentin and some influencing factors.

Objectives: The present study focused on the piezoelectricity of human dentin. The effects of moisture content and orientation of tubules were investigated.

Methods: Fresh human dentin was cut with two surfaces generally parallel to the occlusal surface.

Synthesis and structure of cerium-substituted hydroxyapatite.

The aim of this study was to explore the effect of cerium ions on the formation and structure of hydroxyapatite (HAP). All particles, prepared by hydrothermal method, were synthesized at varied X(Ce) = Ce/(Ca + Ce) (from 0 to 10%) with the atomic ratio (Ce + Ca)/P fixed at 1.67.