Comparative evaluation of two commonly accepted tests for adjustment of fixed prosthetic constructions.

Regardless of the great advance in prosthetic dentistry related to the development of new more elaborate materials and methods, the dentist must often correct some defects of the newly fabricated prosthetic constructions. In dentistry practice worldwide two tests for adjustment of fixed prosthetic constructions are applied most often - the silicone test and the suspension of Fe2O3 (rouge) and chloroform. The capabilities of the suspension of chloroform and rouge to assess the preliminary contacts between the prosthetic construction and the dental tissues haven't been reviewed in the dentistry literature in Bulgaria. The test is not familiar to the practicing dentists and this is an obstacle for its wide application in everyday practice. The purpose of the current study was to compare the advantages and disadvantages of the silicone test and the modified suspension of halothane and rouge recommended in the recent years. The assessment of the capabilities of the two tests for adjustment is based on the results of their application in the adjustment of crowns and bridges on the working model and on the prosthetic field. The results demonstrate that the two tests have different capabilities in different clinical situations and their concomitant use will allow more precise prosthetic treatment.

Correlation between overcontouring of fixed prosthetic constructions and accumulation of dental plaque.

INTRODUCTION: In prosthetic treatment with fixed prosthetic constructions the reproduction of the dimension and form of natural teeth crowns is important for the preservation of normal articulation-occlusal relationship as well as for periodontal health. THE AIM of the study was to evaluate to what degree there is an attempt to preserve and reproduce the natural dental contour in everyday dental practice and its impact on plaque accumulation. MATERIALS AND METHODS: The study was performed in patients with different types of fixed prosthetic constructions - metal, metal-ceramic and the combination of metal/plastic with intact symmetrical homonymous teeth. We used the index of J. Silness and H. Loe (1964) for evaluating the amount of accumulated plaque on the prosthetic construction in the area between the equator of the tooth and gingival margin. RESULTS: Our study reveals that the practicing dentists and dental technicians underestimate the preservation of natural dimension and form of dental crowns. Most often they are significantly enlarged for solving the esthetic requests of the patients. The basis for this is the incorrect preparation of the teeth and the ignorance of the negative effect of overcontouring of fixed prosthetic constructions on the periodontium by the practicing dentists. The overcontouring leads to a greater accumulation of dental plaque in the area between the equator and the margin of the gingiva.

The impression as a means for analysis of clinical mistakes in fixed prosthodontics.

Earlier and more recent clinical observations show that mistakes made in the early clinical stages of treatment have a negative effect on the time of effectiveness of the prosthetic treatment and its medicobiological value. Finding the most common mistakes and deviations from the clinical and laboratory protocol is of primary importance for creating a qualitative clinical technique and adequate training programs. On the other hand it is difficult for the practicing dentist to perform self-control in his everyday technique for preparation and taking impressions. The purpose of the study was to evaluate the most commonly made clinical mistakes and find how to detect them in time by analysis of the impressions. The study was performed on impressions for crowns and bridges made by generally practising dentists in different regions of the country. The impressions were divided into groups according to manner of their taking - with or without an impression tray. Transverse cuts in planes parallel to the longitudinal axis of the dental stump were used to evaluate the axial inclination and the borders of preparation. The results from the study show that the generally practicing dentists make serious mistakes in the preparation of the teeth for crowns. These mistakes are aggravated by the wrong strategy in taking the impressions. The analysis of the mistakes in the training programs for students and post graduate students is important because it diminishes the chance of their occurring in future. Each dentist can use the impressions taken by him as a means for self-control and evaluation.

[A device for thermo-compressive formation of plastic foil for stomatological purposes]. / Prisposoblenie za termokompresivno oformiane na plastmasovo folio za stomatologichni tseli.

A device is proposed, by which bigger plastic details for stomatological purposes can be formed via high air pressure. For that purpose, a gas flow is led away to a special bell through an armoured rubber hose from the compressive installation of the somatological unit. The plastic foil is fixed by a clip-holder, adjusted also for work with basis-plaques. After the formation of the foil-matrix and its cooling, the air pressure is stopped. The device is prompted by the desire to facilitate the production of details necessary for the clinic, for the dental mechanic laboratory and for the stomatological research work. The device has been put into practice in the Stomatological Faculty, HMI, Plovdiv.