Annealing induced structural evolution in feldspar dental glass-ceramics investigated by solid-state NMR spectroscopy

Abstract Glass-ceramics are an attractive oxide-based material routinely used for biomineral repair such as porcelain veneers in dental crown applications. The short- and long-range structure of a commercial glass-ceramic feldspar material, VITA VM9, has been investigated as a function of annealing temperature. The relative amounts of amorphous and crystalline components were monitored using a combination of powder X-ray diffraction and solid-state 23Na, 27Al, and 29Si nuclear magnetic resonance spectroscopy. The insight gained from this study was then applied to analyze a series of synthetic lab-grade ceramics Na0.5K0.5Al1–xMxSi3O8 (x = 0.1; M = B, Al, Ga), whose onset of crystallization was found to resemble that of the commercial ceramic material.