Spectroscopic Analysis of Dental Glass-Ceramics
Date
2003
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Alfred University. Faculty of Ceramic Engineering. Kazuo Inamori School of Engineering
Abstract
Over the years there have been significant improvements in the field of restorative dentistry, and yet the process of shade selection remains primitive. A number of materials have been developed for the restoration and replacement of teeth, but none of them have demonstrated efficiency in restoring the tooth to its natural color. The demand for a more esthetic dental restoration is increasing in the recent years. The usual method of shade matching using shade guides is subjective and hence is insufficient to meet this demand. To reduce the subjectivity of color matching, derivation of a simple figure of merit is imperative and to achieve this, colorimetric data of dental glass-ceramics should be deduced. The main objective of this study was to spectroscopically evaluate glass-ceramic samples proposed for use in commercially available shade guides. A spectrophotometer was used to measure diffuse reflectance, specular reflectance and diffuse transmittance of all the samples. A fluorimeter was used to examine the fluorescence of the samples. Results from the glass-ceramic samples were compared to the results obtained from conducting similar experiments on natural teeth. Effects of heat, hydration, and UV exposure were also quantified. To obtain the crystal phases and the crystal morphology, XRD and TEM analysis of the samples were performed. A DSC analysis was also performed on the samples to obtain their temperature of crystallization. The spectra show the similarity in the curves obtained for the samples and natural teeth. A figure of merit developed based on the equations obtained for the curves and the ABBE number dispersion factor was inconsistent and hence the ΔE values obtained were studied and evaluated. This figure of merit did not include the fluorescence data as fluorescence could be reproduced by incorporating rare earth ions into the composition of the glass-ceramics. The figure of merit developed would reduce the subjectivity involved in the shade selection and communication process.
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Keywords
Dental materials, Glass-ceramics, Spectroscopic analysis