[Method and optical device for exactly hinge axis localization tested on original phantom]. / Metoda si dispozitive optice pentru localizarea exacta a axei balama. Verificari pe fantom original.

The quickly and exactly method of location of the hinge-axis is based on the moiré effect, produced between two superposed optical nets, one of it being moved. A face bow is fixed on the mandible to the occlusion rim. Two optical devices are mounted on the bottoms of the face bow. Two other optical nets are applied on the skin, corresponding to the TMJ. During the opening movements of the mandible when a pure rotation of the mandibular condiles take place on the TMJ, the optical nets are displaced and me exactly register the place corresponding to the rotation axe and we can note on the skin the hinge axis. The checkout was done using a phanthom achieved in our department, consisting of a skull made up of polyestheric resins and an elastic element made up of PVC.

[Moiré effect. Application in medicine and dental technology]. / Fenomenul moiré. Aplicatii în medicina si în tehnologia protezelor dentare.

Moiré effect is an optical phenomenon that occurs when two similar arrays of alternately opaque and transparent lines or dots are superimposed upon each other. Superimposition of two such similar, but slightly different, line arrays causes interference between the arrays; the interference results in the formation of moiré fringes. There is a definite relationship between the pitches of the two arrays and the spacing of the fringes. Therefore, given the pitch of one of the arrays and the distance between the moiré fringes, the pitch of the other array can be calculated. The moiré effect can be used to determine the development of cutaneous tumors in a very short time-frame and to assess the measurement of dental eruption within 20 minutes. The 3-D facial, palatal and dental morphology can thus be evaluated very accurately. The CAD/CAM dental technology is actually possible due to the moiré effect.

[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.

[CAD/CAM technology-elaboration of electronic model through optical impression in the fabrication of the dental prostheses by a computer assisted device]. / Tehnologia CAD/CAM--elaborarea modelului electronic prin amprentarea optica în cadrul technologiei de realizare a protezelor dentare asistate de computer.

In modern CAD/CAM technology of dental prosthetics, the "optical impression" taken by special video cameras deploying 3D-recording of the oral situation (Cerec 1, Cerec 2) initiates the computer-generated production of a digital model. The computer receives and renders the digital data obtained through "optical impression" i.e. data acquisition not as a "negative" of the oral situation but as a "positive" copy of it, namely as a digital model in a virtual environment which can be displayed on the screen and be further used in the fabrication of dental prostheses by means of a computer-assisted device (CAM or CIM).

[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.

[Experimental study using 86Rb on the permeability of biomaterials used for occlusal pit and fissure sealants]. / Recherches expérimentales à l'aide du 86Rb sur la perméabilité des biomatériaux utilisés pour le scellement des fissures et des fossettes occlusales.

In experimental in vivo work, we used 45Ca and 131I radioisotopes to establish the impervious nature of biomaterials used for filling. A comparative study of permeability in 3 biomaterials used as pit and fissure sealant, alkylcyanoacrylate, Delton and Sigilar was conducted with 86Rb radiosotope. The materials were applied to the surface of 60 natural intact teeth divided into 3 sets and 6 groups. Each of the 3 types of materials were applied no one set of teeth. Within each set, a group of 10 teeth were labeled with 86Rb for 30 minutes and the other group was marked with 86Rb for 60 minutes. After washing, gamma emission was measured immediately after labeling then again 24 hours later. Results indicate that the biomaterial Delton is the least permeable to 86Rb, gamma counts being approximately 20-times lower with Delton than with alkylcyanoacrylate and Sigilar.

Technical and biophysical aspects in prosthetic occlusal rehabilitation for edentulous teenagers.

The loss of anterior teeth may be transient solved by temporary adhesive bridges (Oslo bridge, Rochette, Ellmann, Neumann, Tschemitscheck, Armatron systems). Provisional crowns and bridges could be used for Brackets fixing. Anterior bridge with subocclusal connector permits transversal expansion. When a successful orthodontic treatment is followed by a prosthetic treatment, it is not important to change the achieved occlusion, by the occlusal framework morphology. The framework design of the metal component can contribute to the improvement of the aesthetic aspect and reduce the cost by using a small quantity of expensive alloy. Cytocompatibility of the used Cr-Co alloy is confirmed by cell culture test.

The awareness of risk and personal relevance in alcoholics.

From the perspective of health professionals, the estimated nine million alcoholics in America are engaged in repetitive health-avoidance behavior. The purpose of this study was to asses whether alcoholics were themselves aware of the risk-taking implications of their drinking, particularly in view of the denial clinically attributed to alcoholics. Horn's Smoker's Self-Testing Kit, modified to measure respondents' attitudes toward excessive drinking and its consequences, was administered to 61 alcoholic inpatients. This instrument evaluates awareness of the health hazards of excessive drinking, awareness of the seriousness of alcoholism as a health problem, awareness of its personal relevance, and the value of stopping, concern with mastery of the drinking problem, and belief in capability for stopping. The results indicated that during sobriety these alcoholics definitely acknowledged the health hazards of excessive drinking, the seriousness of the problem, its personal relevance, and the value of stopping. However, subjects generally anticipated great difficulty in making any significant change in their self-destructive drinking patterns.