[Research in the dental laboratories in Thessaloniki relatively to the planning and the kind of the fixed prosthetic constructions]. / Hereuna sta odontotechnika ergasteria Thessalonikes schetika me te schediase kai to eidos ton akineton prosthetikon ergasion.

It is well known that Prosthetics is the part of Dentistry that needs the dentist's and D. technician's cooperation in order to be completed. For this reason the aim of our research was on one hand to record the planning and the kinds for the fixed bridge work that proceed from the cooperation of the two sides and on the other hand to evaluate the results, to locate the weak points and to give the possibility to our department to obtain clearer and more entire of the Prosthetic treatment given by the dentists and D. technicians. So from this research and the answers to the four sections which refer to the above mentioned subject, we had some information about the plannings and the kinds of the crowns, the way of their forwarding the importance of the aesthetic part of the constructions and at last the problems which are created on the dental laboratories by the way which the teeth are prepared.

[Research in the dental laboratories in Thessaloniki referring to the categories and the elaboration of the dental alloys for the fixed prosthetic constructions]. / Hereuna sta odontotechnika ergasteria Thessalonikes schetika me tis kategories kai ten ergasteriake epexergasia ton odontiatrikon kramaton gia akinetes prosthetikes ergasies.

The research that is presented in this article is a statistical evaluation with goal to scrutinize which classes of the dental alloys are being used by the dental laboratories in Thessaloniki for porcelain and acrylic bridge work constructions. On the other hand many elements concerning to the elaboration of the new dental alloy have been checked and evaluated. The result of this research that covers the 90% of the total number of the dental laboratories of Thessaloniki lead to the following conclusions: 1. The dental laboratories in Thessaloniki use in high percentage alloys with low cost for the fixed prosthetic constructions. 2. The Ag-Pd dental alloys for the metal-acrylic and the Ni-Cr alloys for the metal-ceramic constructions occupy the first position in frequency. 3. The dental Technicians must improve even more the elaboration of the new dental alloys.

[Influence of the sprue casting design on the surface porosity of the silver-palladium dental alloys]. / E epidrase tes schediases ton agogon chyteuses sten epiphaneiake porose ton argyropalladiouchon kramaton. (Anakoinotheke sto 70 Panellenio Odontiatriko Eunedrio. Athena, Oktobrios 1987).

The purpose of this work is to investigate and find out the best "design" of the casting sprues on the area and the number of the surface porosity when we cast silver-palladium dental alloys for metalloacrylics fixed partial dentures. Our observation and research have been done on 216 external surfaces from 72 M.O.D. specimens, which were casted using four different designs of casting sprues and three types of silver-palladium dental alloys (Panag, Pangold and Palliag M.). The evaluation of our findings and statistical analysis have been done. The findings of our study are the following. 1. It has been found that the "alloy" factor doesn't influence the area and the number of the surface porosity we examined, on the contrary it has been found that the "design" factor has great influence on the area and the number of the dental alloys. 2. The use of chill-sets and the securing of sprue button alloy decrease the area and the number of the surface porosity when we cast silver-palladium dental alloys. 3. The straight sprues and the placing of the specimens near the heat-center of the mold created much better conditions for decreasing the number and the area of the surface porosity than when we use the preci-roto system.