The field of biomaterials imposes a multidisciplinary approach that requires the involvement of sciences such as biology, medicine, chemistry and materials engineering so that the material implanted in a living organism does not cause any adverse reaction. This research area of biomaterials is considered as fascinating and challenging. It's fascinating because of its potential applications and the need to improve the quality of life. It is challenging due to the various complexities it faces when biomaterials encounter biological environments for the longevity of life by maintaining or restoring tissue or organ functions. Metallic biomaterials are used as pivots for anchoring dental implants and as parts of orthodontic devices such as crowns and bridges of prostheses. Ti-6Al-4V is well known as a corrosion resistant alloy for dentistry applications due to this film of titanium oxide formed on its surface. However, the inflammatory conditions ad protein presence could affect the corrosion resistance of this alloy. Our research work aims to investigate the effect of albumin and inflammatory conditions to corrosion resistance of Ti-6Al-4V in saliva Fusayama Meyer biological solution. In order to simulate the peri-implant inflammatory conditions in vitro studies were conducted with addition of hydrogen peroxide (reactive oxygen species, found during inflammation) and albumin the most typical protein of biological fluids. Electrochemical methods were applied for corrosion investigations. The results provide evidence that titanium’s alloy corrosion resistance is affected by inflammatory conditions and albumin presence in saliva biological solution.

We evaluated the biocompatibility of four types of commercial alloys (two CoCr alloys and two NiCr alloys) used to make dental bridges. For the cell biology tests, a human osteosarcome type culture cell line MG63 (American Type Culture Collection) was used. Taking into account the results obtained, it can be said that the best results in terms of cell proliferation were observed for the Ni-Cr / Solibond N alloy closely followed by Co-Cr / Heraenium CE, then Co-Cr / Solibond C and Ni-Cr / Kera N, while cell viability tests revealed that the Co-Cr / Heraenium CE alloy exhibits the best biocompatibility, followed by Ni-Cr / Kera N, Co-Cr / Solibond C and Ni-Cr / Solibond N.

In order to increase the patient�s quality of life, interdisciplinary studies on dental materials are becoming more and more frequent in an attempt to assess as accurately as possible the resistance of dental restorations over time. One of the methods of analysis of resistance to the masticatory forces of dental restorations is the finite element method (FEM). We studied a 3-element dental bridge made of a metallic Co-Cr-Mo alloy and dental ceramics, designed for the prosthesis of a tooth 3.6. On each element of the dental bridge we applied a force of 250 N in the direction Z and a force of 100 N in the Y direction. The most vulnerable areas, where the highest stresses occur, are located predominantly in the neck regions and around the points of contact between the elements of the dental bridge. However, the experimentally determined values have low intensities that would not endanger the resistance of the restoration unless it is overloaded.

In our study we compared in vitro the tensile strength of 4 types of adhesive systems used for brackets, two using bonding and two self-etching. The detachment test were made by the Instron� 8801 universal mechanical testing machine, from the Mechanical Testing Laboratory of the Materials Resistance Department, the Faculty of Engineering and Management of Technological Systems, the Polytechnic University of Bucharest. From the experimental results we find that the used adhesives offer good shear resistance. Vertise Flow adhesive used for sample 2, which has the highest shear stress at break (tmax ~ 25 MPa), is clearly highlighted. Vertise Flow is follow by the Orthocem adhesive used for sample 1 with tmax ~ 14 MPa, then the Neobond adhesive used in sample 4 with tmax ~ 13 MPa, and the weakest of the adhesives is Grandio Flow used for sample 3 (tmax ~ 12 MPa). We believe it is necessary to carry out further studies on larger batches of samples to obtain results that can be validated by statistical analysis.

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