Translucency of a Dental Porcelain Mixed by Two Ceramic Slurry Methods: A Bayesian Comparison

Abstract

Background. The ceramics industry produces porcelain pastes using a controlled ratio of water and porcelain powder. Two methods are used to produce a dental porcelain paste: one-step mixing or incremental mixing. Objective. To evaluate the optical properties of a feldspathic dental ceramic using two different ceramic paste preparation methods using a Bayesian approach. Materials and Methods. Two groups of feldspathic porcelain discs, an incremental mixing group (n = 40) and a one-step mixing group (n = 40), were assessed. Groups were evaluated using spectrophotometry, and the translucency parameter (TP) of each sample was calculated. Surfaces were characterized by AFM and SEM. Statistical analysis was performed using a Bayesian approach. Results. Translucency parameter values of the incremental mixing group ranged from 1.65 to 3.41, while values for the one-step mixing group ranged from 3.62 to 5.74, this difference being statistically significant. The lowest roughness was obtained on the surface of discs in the one-step mixing group. Conclusions. Feldspathic porcelain with lower translucency and higher roughness was obtained using the incremental mixture method.

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

“…It was noticed that increasing the ceramic thickness by the technicians T1 and T2 increased the color difference (∆E) between the target shade (3M2) and the duplicated shade of the specimens, which may be due to poorer ceramic compaction for greater thicknesses. It was observed that these two technicians used a thin ceramic mix with excess water that may evaporate during the firing process, leaving voids acting as scattering centers with a pronounced negative effect at higher ceramic thicknesses [28]. While in the thinner ceramic thickness, the effect of these defects was not as exaggerated as that in thicker sections with accumulated voids.…”