IV 2015

Ceramic materials for dental prosthetics – color gradient zirconia blocks   
In the past years there has been an intensive development of cosmetic dentistry. The appropriate selection of artificial crown shade corresponding to the natural teeth color is one of the most important aspects of aesthetic reconstruction of dental crowns. Hence the purpose of the work described was to develop a method for manufacturing zirconia blocks characterized by gradient color change. Colored ready-topress powders in shades of A1, A2, A3 and A3.5 of VITA color scale were used and gradient test samples were formed by pressing. Their physical properties, structure, color and saturation distribution were evaluated. Overall assessment of the usefulness was performed by specialists from prosthetic company. The results of the research and experimental tests have shown that the proposed method allows to obtain zirconia blocks with a color gradient, which can simplify the currently used methods of staining and veneering of prosthetic restorations. It seems possible to replace the time-consuming and diffi cult veneering by only painting techniques. Experience gained from the study described in the present article will allow to apply this method to the other VITA color scale ready-to-press powders.
Zdzisław Wiśniewski M.Sc. Eng.

Mullite powder synthesis by solid state reaction in powder bed
The paper presents interpretation of results mullite the base composition (3Al2O3 · 2SiO2) which have been synthesized from nanometer size alumina and amorphous silicon dioxide. The results were compared to the effects of the mullite synthesis from micrometer size raw materials. Obtained at different temperatures of synthesis, sintered bodies have been analyzed under qualitative and quantitative phase composition (XRD) and microstructure (SEM). The paper presents interpretation results and determinates substrate’s grain size of raw materials dependence on the synthesis temperature.
Piotr Taźbierski M.Sc. Eng.

The impact of quality performance insulating glass units to preserve their usefull parameters
Passive construction requires the use of energy-efficient building materials. Striving to achieve high thermal insulation of buildings is reflected also in the production of insulating glass units. It is important that the glass installed in the building were of high quality because only then will be able to perform its function. The article discussed the basic functions insulating glass units, normative requirements and methods of their control. Presented quality insulating glass units and a factor in obtaining these materials good performance characteristics.
Anna Balon-Wróbel M.Sc. Eng.

Effect of heat treatment and the nature of the interlayer on the mechanical strength of laminated glass for building
The article described the types of glass and polymeric materials used for the construction of laminated glass and laminated safety glass, The paper presented comparative results of different designs of laminated glass on four point bending strength, pendulum impact and ball. The method of determining the effective thickness of laminated panes used for the calculations of mechanical strength was described.
Iwona Kozubek M.Sc Eng., Jacek Brzezicki M.Sc. Eng