Hellenika stomatologika chronika. Hellenic stomatological annals最新文献

The retention of a full upper denture is seriously affected by the border seal and especially by a correct and strong postpalatal seal, which occurred before the receiving of the final impression. In this article we describe the effects of a correct and strong pospalatal seal on the function of a full upper denture, as well as the procedure that should be followed in order to achieve a correct posterior palatal seal.

The aim of this study is to investigate the dimensional changes of hydrocolloid impression materials agar type and alginates, when they are placed in fluids for AIDS virus sterilization as Sterile pack, alcohol 75%, sodium chloride 10% and Cidex for 40 min. It was found out that when the hydrocolloids were placed in alcoholic and Sterile pack fluids a great deal of changes happened (contraction and shrinkage) that made the sterilization in them impossible. The percentage of linear extention and imbibition noticed in hydrocolloids when they were placed in sodium chlorides and Cidex solutions showed that sterilization in them is usually possible. The best way of sterilization is to make a gypsum model from the hydrocolloid impression and place it in the furnace for 30 min in 60 degrees C.

Since the number of dental journals grows bigger every year it becomes important for the practitioner researcher teacher and editorial stuff to be informed for the content of the journals. The scientific reports in four Greek dental journals were recorded and evaluated according to several parameters. All the reports published in the years 1982-1986 were recorded and these were covering more than 90% of the total number of Greek scientific articles of this period. The results revealed an association between field and journal as well as between type of the report and journal, type and number of reports, type and number of authors, type and volume of the report, type and presence of tables, figures or photographs, type and number of references and type and cost of the report. It was also shown that in their largest percent the reports were dealing with Oral Medicine (16%), were of the review type (56.1%), were written by only one author (37.1%), contained no tables (58.8%) or diagrams (53.7%), contained photographs (63.8%), had references on foreign articles (87.7%) and cost not more than 8.000 drs (75.5%).

The increasing number of old people in today's society is a reality. They are a group, whose special needs and medical problems are dealt in Geriatrics. Geriatric dentistry is the branch of Dentistry concerned with their dentical problems. In this article we discuss some of these special problems as an attempt to make this subject more comprehensible to the general practionner.

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.

Finishing and polishing an amalgam restoration, is considered as an important and necessary step of the restorative procedure. Various polishing techniques have been recommended to success a smooth amalgam surface. The aim of this study was to investigate the influence of three different polishing treatments on the marginal integrity and surface smoothness of restorations made of three commercially available amalgams and a glass-cermet cement. The materials used were the amalgams, Amalcap (Vivadent), Dispersalloy (Johnson and Johnson), Duralloy (Degussa) and the glass-cermet Katac-Silver (ESPE). The occlusal surfaces of the restorations were polished by the methods: I) round bur, No4-rubber cup-zinc oxide paste in a small brush, II) round bur No 4-bur-brown, green and super green (Shofu) polishing cups and points successively and III) amalgam polishing bur of 12-blades-smooth amalgam polishing bur. Photographs from unpolished and polished surfaces of the restorations, were taken with scanning electron microscope, to evaluate the polishing techniques. An improvement of marginal integrity and surface smoothness of all amalgam restorations was observed after the specimens had been polished with the three techniques. Method II, included Shofu polishers, proved the best results in comparison to the methods I and III. Polishing of glass-cermet cement was impossible with the examined techniques.

The calcium phosphate system, and in particular Hydroxylapatite, has been the subject of intensive investigation. Recently dense, non-resorbable particulate and block forms of hydroxylapatite have been developed for use as tooth root, bone augmentation and bone replacement material. Dense and porous hydroxylapatite forms have been used clinically for periodontal defects, alveolar ridge maintenance and alveolar ridge deficiencies. In this study the different clinical uses of hydroxylapatite in the Maxillofacial area are presented.

In our days, Posterior Composites are in the way to replace the traditional and well established materials, such as the amalgam, from the region of the posterior teeth. As time passed however, the first problems connected with these materials were soon to appear. If composites must be used in posterior teeth for occlusal bearing fillings, wear is an important consideration and stands as one of the main problems concerning these materials with serious clinical consequences for the restoration as well as for the occlusion. It is difficult to give an answer to the question concerning the resistance or the behavior of the Posterior Composites to the wear mechanisms. There is no doubt that with the continuous improvement of the Posterior Composites there is also an improvement in the degree of wear. Therefore the purpose of this bibliographical review is to examine the phenomenon of wear and the mechanisms which cause it. We will deal mainly with the clinical study of this phenomenon, while we will also try to explain the behavior from the viewpoint of the wear of the various types of Posterior Composites which are in use today.

The purpose of this article is to describe and discuss a modified amalgam onlay preparation which is a conservative approach to restoring extensively decayed teeth. The cavity preparation for the amalgam restoration appears similar to a preparation for a cast restoration and at the same time the preparation provides a 90 degree cavosurface bevel. The amalgam onlay preparation may be used in any class 1 or class 2 cavity preparation when the cusps are weak and should be protected by the restorative material. The modification of the cavity which is the angulation of the buccal and the lingual walls provides convenience to the clinician during the condensation and carving of the amalgam. In addition to this the natural contours of the tooth are preserved and in cases of upper posterior teeth the buccal surface of the cusps is almost completely preserved and the appearance of the amalgam is not different from that of a gold onlay restoration.

The influence of four antiseptic solutions on some dental materials was examined in this study. The antiseptic solutions were sodium chloride 10%, alcohol 75%, Cidex and Sterile pack fluid, whereas the dental materials were dental modelling wax, impression compound, shellac base plate and zinc-oxide eugenol paste. The change of weight and the change of length which were observed in 40 minutes were measured. According to our results the modelling waxes, as well as the impression paste are not influenced by the antiseptic solutions. The impression compound must not be sterilised in Sterile pack fluid, which dissolves it, but it can be floated in the rest of the solutions. The shellac base plates are influenced by all the antiseptic solutions studied, especially by alcohol 75% and Sterile pack fluid.