THE ART OF DENTAL CERAMICS

The beauty and challenge of dental ceramics lies in the skill of the technician to copy, imitate and reproduce the nature which in itself is beautiful, unpredictable and unique. In addition to challenges of being in accordance with the nature, aesthetics is still a larger challenge. The combination of natural appearance and aesthetics presenta the key of patient΄s contentment.

When making prosthetic replacements, special attention is paid to dental ceramics itself, as it presents the "crown" of each prosthetic restauration. Comprising everyone in one place, the physician and the patient, the dental technician, as is the case with the Polyclinic Dr. Jelušić, ideal prerequisites are formed to use all the aspects and attitudes when creating aesthetics.

The smile, appearance of the face, the character of a person and finally, very important, desires and expectations of the patient are the factors considered when preparing a prosthetic replacement. The size and form of the teeth are connected with the appearance of the face, nose and the lips. It is therefore essential to see the patient before starting to create dental ceramics.

The process of "stacking"ceramics develops in several stages and it assumes application of layers of dental ceramics that are baked at high temperatures. The fabrication process of ceramic layers follows the structure of a natural tooth. Each natural tooth has the basic tissue called dentine and the outer, hard and transparent layer called enamel. When making ceramic prosthetic replacements, the natural tooth structure is followed, it is therefore worked in layers corresponding to dentine and enamel. The last, surface layer of the ceramics is applied separately and it contributes to the final aesthetic and visual effect of the prosthetic work. It is in this final layer that various imitations of the natural enamel, like cracks, coloured defects etc. can be made.

There are several types of prosthetic restorations that can be classified under the term of dental ceramics. Dental ceramics is the final layer of a prosthetic replacement, giving the final form and aesthetic propeties to the prosthetic restoration. 

Metal-ceramics is dental ceramics applied on a metal base. The metal base provides it with firmness and resistance, whereas the layers of dental ceramics secure the final appearance. As the metal is dark, prior to applying the layers of ceramics, it has to be hidden or masked by special colours, in order to get neutralized. Metal-ceramics is presently considered to be the standard in the fabrication of ceramic prosthetic restorations, however, more superior materials are available that have no deficiencies of the metal-ceramics combination.

Zirconium-ceramics resembles the metal-ceramics combination in all the aspects, however its base is made of zirconium. Zirconium is a synthetic mineral of very good mechanical properties, sufficiently firm to form the base of ceramics. The shade of its colour is white (neutral and aesthetic one) and the organism cannot "perceive" it, because it belongs to the group of bio-compatible materials, like titanium used for implant fabrication. Zirconium-ceramics restorations are metal-free and their base is the white structure, providing, as related to metal-cheramics combination, better aesthetic properties.

integral ceramics is the most suitable material used in the fabrication of prosthetic restorations. Integral ceramics has no special base as the metal-ceramics or zirconium-ceramics combinations, but the whole tooth is made from the same material. In addition to their excellent characteristics, presently available materials (lithium disilicate ceramics) also have excellent mechanical properties, making this material an ideal one for fabrication of prosthetic restorations. Tooth colour is selected according to the standard schale; in relation to the ceramic base, its shade is then additionaly nuanced to achive the aesthetic maximum. Finally, we obtain the prosthetic restoration of excellent mechanical and aesthetic characteristics, fabricated from one unique material. Such restorations are most commonly related to computer-managed CAD/CAM technology allowing a very quick work, thereby maintaining all the aesthetic and mechanical characteristics.

Integral zirconium is a special material used in fabrication of large aesthetic rehabilitations. It is most commonly used in fabrication of large prosthetic and implant-prosthetic rehabilitations with bridgeworks. This material is suitable for the largest rehabilitations, retaining thereby excellent aesthetics characterized by transparency, with exceptional mechanical properties and the fact that the prosthetic restoration has been fabricated from the bio-compatible metal-free material.

The selection of prosthetic material should always follow the indication, specific situation of each patient respectively. Material selection is sometimes limited by technical factors, such as size or range of the prosthetic restoration. Biological factors, on the other hand, such as allergies to certain components of dental alloys (nickel, usually) also limit material selection. Finally, the desires of patients and the advantages and deficiencies of each of all the materials should be considered when selecting the restorative technique.