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Background: Ceramic restorations are widely used nowadays as the esthetic demand has increased in the worldwide population, and lithium disilicate and feldspathic porcelain materials are the most widely used veneer materials. The traditional removal procedure for veneers was recently replaced with the use of laser technology to debond the veneers so that the de-bonded veneers can be preserved and re-used. Aim: Up to now, there have been few studies regarding using lasers to remove ceramic laminate; thus, it is clear why this research topic is important for examining the efficiency of lasers in the use of de-bonding for different ceramic laminates with varying compositions and materials. Materials and Methods: This study employed forty-five normal human maxillary first premolars with comparable proportions. The forty-five teeth were initially split into three groups of fifteen teeth, and the teeth were chosen at random. Each group fused pairs of various ceramic materials. A total of fifteen teeth in the first group underwent feldspathic porcelain restorations. The second group contained fifteen restorations made of lithium disilicate glass-ceramic CAD-CAM. In the third group, fifteen teeth were restored using glass-ceramic that had a lithium disilicate glass-ceramic ingot. The RelyX Veneer A1 shade, available from 3M EPSE in the United States, was used to bond all the samples. The specimens were then submerged for approximately 24 h in distilled water at 37 degrees Celsius in order to simulate the conditions in an oral cavity. An Er,Cr: YSGG laser (Waterlase, iPlus, Biolase, from USA) was used with a turbo headpiece and an MX7 sapphire tip for irradiation. Results: The time needed for the ceramic disc to debond was calculated using a digital stopwatch. The average removal times for the feldspathic porcelain, lithium disilicate glass-ceramic ingot, and lithium disilicate glass-ceramic CAD-CAM were 10.067 ± 1.668 s, 5.200 ± 1.146 s, and 5.133 ± 1.125 s, while the removal times ranged from 8–12 s, 4–7 s, and 4–7 s, respectively. Compared to the other ceramic materials, de-bonding the feldspathic porcelain took longer. Conclusions: According to this study, the Er,Cr: YSGG laser application using the same study parameters made it simpler to de-bond lithium disilicate and feldspathic porcelain. Lithium disilicate, as opposed to feldspathic porcelain, transmits laser light more effectively; hence, the results varied depending on the materials, and the debonding occurred primarily at the veneer–cement interface. Full article

Accurate analysis using a simple and rapid procedure is always the most important pursuit of analytical chemists. In this study, a new sample preparation procedure, namely the shaker cup (SH) method, was designed and compared with two sample preparation procedures, commonly used in the laboratory, from three aspects: homogeneity of the sample–flux mixture, potential for sample contamination, and sample preparation time. For the three methods, a set of 54 certified reference materials (CRMs) was used to establish the calibration curves, while another set of 19 CRMs was measured to validate the results. In the calibration procedures, the matrix effects were corrected using the theoretical alpha coefficient method combined with the experimental coefficient method. The data of the major oxides (SiO₂, TiO₂, Al₂O₃, TFe₂O₃, MnO, MgO, CaO, Na₂O, K₂O, and P₂O₅) and minor elements (Cr, Cu, Ba, Ni, Sr, V, Zr, and Zn) obtained by wavelength dispersive X-ray fluorescence spectroscopy (WD-XRF) were compared using two derivative equations based on the findings by Laurence Whitty-Léveillé. The results revealed that the WD-XRF measured values using the SH method best agreed with the values recommended in the literature. Full article