STATEMENT OF PROBLEM Porcelain fused to zirconia prostheses are widely used. However, porcelain chipping, spalling, fracture, and delamination are common clinical problems. Residual stresses of thermal origin have received attention, but clear data and firing guidelines remain absent. PURPOSE The purpose of this study was to measure the influence of heating and cooling protocols on the streng...

The fluorescence of porcelain crowns recovered from the mouth of an unknown murder victim, and several control porcelain samples, were examined by fluorescent examination lamps. The fluorescence from two of the control samples was quite similar to that from the porcelain crowns recovered from the victim. To increase the objectivity of the results by quantitative analysis, the composition of eac...

Jacket crowns, metal-bonded porcelain crowns and bridges, made by vacuumfiring dental porcelain, have been considered comparatively stable in the oral cavity. In clinical practice, however, stains, slight surface roughness or abraison are sometimes observed on porcelain prosthetic appliances that have been retained for a long time. But studies related to the durability of such porcelain prosthe...

The differentiation of porcelain from tooh using fluorescence emission was investigated as a basic research for the visual detection of porcelain-restored teeth in mass dental health examinations. The fluorescence spectra were taken from the extracted human maxillary central incisors and five types of porcelain by excitation using the light 380-470 nm. There was a clear difference in fluorescen...

Several studies have investigated toughening porcelain that is layered over a frame or a core. The introduction of residual compressive stress to the surface of porcelain has been shown to be effective to strengthen it. In the present study, nanoparticles of precious metals of silver and platinum (rather than non-precious metals) were used to evaluate if they could increase the fracture resista...

One of the reconstructive choices for the completely edentulous patient is the placement of multiple implants and the fabrication of a fixed implant-supported complete denture. These patients experience an improvement in masticatory performance over patients who wear complete dentures. The fixed-implant complete denture consists of a metal bar with acrylic resin and denture teeth connected to i...

BACKGROUND Chip-off fracture of veneering porcelain has been described as the most frequent reason for the failure of zirconia-based fixed partial dentures. The purpose of this study was to evaluate the shear bond strength (SBS) of two commercial zirconia core ceramics to their corresponding veneering ceramics. MATERIALS AND METHODS Zirconia disks with 7-mm diameter and 3-mm height were prepa...

The aims of this study were to determine the fracture origins and crack paths in the porcelain of clinically failed bilayer ceramic restorations and to reveal the correlation between the porcelain failures and material properties. Three clinically failed crowns of each material (bilayer zirconia crowns, galvano-ceramic crowns, and porcelain-fused-to-metal crowns) were collected and underwent fa...

The royal porcelain manufactories in eighteenth-century Continental Europe were sites of production that implemented chemistry in three different areas: manufacture of porcelain paste, preparation of pigments for ornamenting porcelain, and construction of furnace along with choice of fuel for firing porcelain. This paper provides evidence for the Royal Prussian Porcelain Manufactory in Berlin b...