J L Ong1, D W Farley, B K Norling. 1. Department of Restorative Dentistry, Division of Biomaterials, Health Science Center, San Antonio, University of Texas, 7703 Floyd Curl Drive, San Antonio, TX 78284-7890, USA. ong@uthscsa.edu
Abstract
OBJECTIVES: This study sought to evaluate the efficacy of using an X-ray diffractometer for the determination of leucite in Finesse, Ceramco II, and IPS Empress porcelains. METHODS: An internal standard, copper, was used. Two quantification methods are presented: (1) the generation of a calibration curve using peak height ratios; and (2) the generation of a calibration curve using peak area ratio. RESULTS: The leucite concentration obtained from the peak height versus concentration calibration curve was observed to be statistically different from leucite concentration obtained from the peak area versus concentration calibration curve. Other information obtained from X-ray powder diffraction include the lattice parameters and volume of the unit leucite cell. SIGNIFICANCE: The leucite contained in the dental porcelains (Finesse, Ceramco II, and Empress) has expanded a-lattice spacings and contracted c-lattice spacings relative to standard leucite. These changes in the lattice parameters resulted in a net expansion of the leucite cell volume.
OBJECTIVES: This study sought to evaluate the efficacy of using an X-ray diffractometer for the determination of leucite in Finesse, Ceramco II, and IPS Empress porcelains. METHODS: An internal standard, copper, was used. Two quantification methods are presented: (1) the generation of a calibration curve using peak height ratios; and (2) the generation of a calibration curve using peak area ratio. RESULTS: The leucite concentration obtained from the peak height versus concentration calibration curve was observed to be statistically different from leucite concentration obtained from the peak area versus concentration calibration curve. Other information obtained from X-ray powder diffraction include the lattice parameters and volume of the unit leucite cell. SIGNIFICANCE: The leucite contained in the dental porcelains (Finesse, Ceramco II, and Empress) has expanded a-lattice spacings and contracted c-lattice spacings relative to standard leucite. These changes in the lattice parameters resulted in a net expansion of the leucite cell volume.