Norina Consuela Forna

Silicone-based Composite for Relining of Removable Dental Prosthesis

A high molecular weight dimethylmethylvinylsiloxane copolymer (Mv = 450, 000) has been synthesized, analyzed, and used as matrix to prepare a composite by mixing with a proper amount of silica. A mixture of Fe2O 3/TiO2 was added to obtain a color close to the natural. 2,4-Dichlorobenzoyl peroxide was also incorporated as a crosslinking catalyst. This heat curable silicone-based formulation was used for relining removable dental prosthesis. The optimum conditions to appliance and hardening of the silicone composite on the prosthesis were established. The main surface (morphology, water contact angle, and water vapor sorption capacity) and mechanical characteristics were evaluated for the crosslinked silicone processed as thick film. The prosthesis relined with silicone was tested on a machine simulating mandible biomechanics both from kinematics and dynamic points of view. The results revealed a good behavior of our composite that remained unmodified after 700,000 mastication cycles.

Experimental and Theoretical Aspects of Aluminum Expanding Laser Plasma

The formation and dynamics of aluminum laser produced plasma are experimentally and theoretically investigated. The visible emitting regions of plasma form two structures of different expansion velocities. Such behavior is in agreement with the transient current recorded by a cylindrical Langmuir probe. Using the hydrodynamic model of scale relativity theory, the plasma dynamics at different time scales are numerically and analytically analyzed.

Profile of the oral healthcare team in countries with emerging economies

Health is a critical dimension of human well-being and flourishing, and oral health is an integral component of health: one is not healthy without oral health. Significant barriers exist to ensuring the worlds people receive basic healthcare, including oral healthcare. Amongst these are poverty, ignorance, inadequate financial resources and lack of adequate numbers of educated and trained (oral) healthcare workers. Emerging economies are encouraged to develop a national strategic plan for oral health. International organizations have developed goals for oral health that can be referenced and adapted by emerging economies as they seek to formulate specific objectives for their countries. Demographic data that assess the nature and extent of oral diseases in a country are essential to sound planning and the development of an oral healthcare system that is relevant, effective and economically viable. Prevention should be emphasized and priority consideration be given to oral healthcare for children. The types and numbers of members of the oral healthcare team (workforce) will vary from country to country depending on the system developed. Potential members of the workforce include: generalist dentists, specialist dentists, dental therapists, dental hygienists, denturists, expanded function dental assistants (dental nurses) and community oral health workers/aides. Competences for dentists, and other members of the team, should be developed to ensure quality care and developed economies should cooperate with emerging economies. The development, by more advanced economies, of digital, virtual curricula, which could be used by emerging economies for educating and training members of the oral healthcare team, should be an important initiative. The International Federation of Dental Educators and Associations (IFDEA) should lead in such an effort.

Aspects in biomaterials used in the manufacture of total prosthesis: Study on a group of patients with high blood pressure

The number of denture wearers is increasing as the number of elderly people continually growing. Different materials used in the manufacture of total prosthesis may cause the appearance of intra-oral lesions, even more for patiens with associate general diseases. It appears that achieving total denture plates with the addition of palladium and / or silver prevents prosthetic lesions.

Researches Regarding the Biomechanics Behaviour of some Impressions Biomaterials Used in Dentistry

The dimensional stability of impression materials is a variable with an impact on the accuracy of dental prostheses; alongside with other factors including the modifications occurred during the material preparation or the impression techniques. The study was based on a laboratory simulation of a clinical situation. The impression materials were: Alginate; Addition silicon materials-AFFINIS and FLEXITIME; Condensation silicon materials-SPEEDEX and OPTOSIL; Polyvinyl siloxane materials-EXPRESS. The impressions were taken at 37 ̊C at 100 per cent humidity and mould in IV class gypsum at intervals of 0 min, 30 min, 1 h, 8 hr, 24 hr and 48 hr. There were taken 3 impressions for each time interval, for each material type as well as for the 2 storage conditions, with a total number of 252 impressions. The measurements of this study were limited to the linear dimension, being observed the changes occurred in one direction, although contraction is a volumetric modification. The statistic assessment of the measurement data obtained in the case of the same type of addition silicon materials recorded an increase of the volumetric contraction type in dry environment and in longer time intervals. The Express material has less significant deformation at room temperature, compared to its being exposed to moist environment. The least significant deformations were recorded in the case of polyether materials automatically mixed.