[Advances and limits in biomedical stress quantification in dento-periodontal structures]. / Posibilitati si limite în cuantificarea solicitarilor biomecanice în structurile dento-parodontale.

The stress quantification in dento-periodontal structures is an important concept, as stress in the tissue and in surrounding structures. A number of clinical studies have suggested figures for such an optimal stress strange. The clinical experiments can be completed with mathematical analysing methods as finite element method. Once the basics of biomechanics understood laws the treatment goes clearly defined, the computer aided design improve the optimal restorative prosthetic or orthodontic appliance. The finite element method (FEM) makes possible the numerical simulation of different clinical situations. Based upon mathematical modelling and extrapolation from experimental studies, practical conclusions can be drawn concerning the different types of forces and their subsequent induced relationship to the stresses. Clinical and histological experiments confirm the mathematical prediction offered by the FEM.

[Influence of corrosion products of the dental alloys on the excitable tissues]. / Influenta produsilor de coroziune ai aliajelor dentare asupra tesuturilor excitabile.

The surface of dental alloys in contact with well conducting electricity solutions are electrochemically corroded. This phenomenon is determined by a proper electric wave generated by electrochemical phenomena present at the limit between the two phases. Because during dental treatments similar conditions with the generation of corrosion waves are present, we decided to study the electrochemical behaviour of the most commonly used dental alloys. The method used in our study is based on the anodic and catodic reactions developed simultaneously, represented by the global curve of polarization that gives informations on the intensity of corrosion waves. We have also studied the influence of corrosion products on the excitable tissues. The results demonstrate the significant influence of metallic ions on the excitable tissues.

[The technic for the reoptimization of laryngeal cannulae by recoating them with a silicone material]. / La technologie de reoptimisation des canules laryngiennes par recouvrement d'un materiau siliconique.

In the laryngeal surgical pathology area, the application of a cannula with temporary or long term indications is necessary for ensuring the respiratory function troubled by various causes (inflammatory, tumor or traumatic) that obstruction the respiratory tract. The most frequently used standard cannula is rigid and does not show proper adaptation for every clinical situation, thus leading to local troubles. In this paper, the realization technique of a rigid/flexible and individual cannula applied after the tracheotomy is presented. In order to carry out the cannula, a rigid material is utilized (acrylic resin) for maintaining the shape and dimensions of the laryngeal stoma. It is also utilized an elastically material (acrylic resin with a retard plug--Simpa) that ensures the optimal adaptation, tight close and tissue protection around the stoma. In co-operation with the ORL Clinic--Recuperation Hospital, these cannulae were applied to fifteen patients pursuing their evolution in time.

[The tension induced by orthodontic forces in the dentoperiodontal system studied by the finite element method]. / Cercetari privind tensiunea indusa de fortele ortodontice în sistemul dento-parodontal prin metoda elementului finit.

The aim of this study was to quantify the stress induced in the periodontal ligaments by the orthodontic appliances. A finite element model of an orthodontic system, applied on a lower premolar, was developed in different loading conditions. The maximum stress values depend on the location, direction and the magnitude of force application.

[The quality assessment of a product with adhesive properties for complete dental prostheses]. / Aprecierea calitatii unui preparat cu proprietati de adeziv al protezei dentare totale.

A formula of dental adhesive using as an agent responsible for this activity an indigenous product, C.M.C.Na 1080, gelified with preservative solution with added astringent agents was elaborated. The possible interaction between the constituents during preservation and the product qualities by determining the pH, extensibility index, sliding limit tension, antimicrobial activity and certain clinical aspects were evaluated.