An Assessment of the Influence of Dental Porcelain Slurry Preparation on Flexural Strength of Different Feldspathic Porcelains

Abstract

Chipping remains a big challenge during the clinical application of glass ceramics in dentistry. The fabrication procedure used affects the mechanical properties of dental feldspathic porcelain and is associated with technical failures. This study aimed to compare the effect of the use of manufacturers’ liquids versus H2O on the flexural strength of glass ceramics. Specimens (n = 120, n = 15 per group) (25 × 4 × 1.2 mm) were obtained using four porcelain powders (Creation CC, IPS InLine, Noritake EX-3, and Vita VM 13). Four groups were produced using porcelain powder and modeling liquid, and four groups using distilled water. The specimens were fired, sintered, and polished. Flexural strength was measured using a universal testing machine. Statistical analyses were conducted using post hoc Tukey’s, two-way ANOVA, and Weibull analysis. Flexural strength values (mean ± SD) of the ceramic-manufacturer’s liquid mixture ranged between 67.2 ± 10.2 and 85.8 ± 12.8 MPA (NR < VT < IV < CR), while flexural strength values of the ceramic–water mixture were between 72.2 ± 6.9 and 95.2 ± 12 MPA (CR < NR < VT < IV). While the choice of the ceramic type significantly affected flexural strength, the use of water vs. manufacturers’ liquid showed in almost all cases no significance. To achieve better flexural strength results, InLine should be used with distilled water mixtures, while all ceramic powders except for Noritake can be used with the manufacturer’s liquid mixtures.

Effect of Ceramic Thickness and Technician Variability on the Shade Duplication of Dental Ceramo-Metallic Restorations

“…The powder/liquid ratio may influence the thickness of the resultant layer [25]. This may be critical, especially for the first layer of the ceramic (washed opaque), which must be applied in a thin layer for both proper thickness and proper wetting.…”

“…This may be critical, especially for the first layer of the ceramic (washed opaque), which must be applied in a thin layer for both proper thickness and proper wetting. In addition, improper wetting of the metallic substructure by a thick mix may lead to the accumulation of voids at the interface [25]. Opaque thickness generally should not exceed 0.1 mm; otherwise, achieving an esthetic result, particularly in thin ceramic thicknesses, becomes impossible [26].…”