Potencial tóxico dos alginatos para uso odontológico / Potencial toxicity of dental alginates

O alginato ou hidrocolóide irreversível é um dos materiais de moldagem mais aceitos e utilizados na Odontologia. Muitas substâncias como zinco, cádmio, silicato de chumbo e fluoretos foram adicionadas em algumas marcas de alginatos, com o objetivo de melhorar suas propriedades físicas, químicas, mecânicas e se tornaram causa de preocupação no que se refere à toxicidade desses materiais. Em algumas marcas de alginatos relatou-se a presença de fluoretos, cádmio, silicatos de chumbo e zinco potencialmente tóxicos, isoladamente ou em conjunto, consequentemente, cuidados especiais devem ser tomados na preparação desses materiais. É necessário que haja um controle contínuo de metais e substâncias potencialmente tóxicas nos alginatos para se evitar a contaminação dos profissionais da área odontológica e pacientes. Nesta revisão analisou-se o potencial tóxico de alginatos usados em odontologia.

Análise quantitativa de fluoretos nos alginatos para uso odontológico / Quantitative analysis of fluorides in alginates for dental use

Este trabalho teve como proposta analisar quantitativamente o conteúdo de fluoretos nos alginatos para uso odontológico e a liberação de fluoretos de moldes desses alginatos em água milliQ,saliva artificial e ácido clorídrico 0,1 mol/l.Foram investigadas sete marcas de alginatos disponíveis comercialmente no Brasil, sendo analisados dois lotes de cada material.As concentrações de fluoretos nas diferentes amostras foram determinadas por potenciometria direta, utilizando o eletrodo seletivo combinado de fluoreto.Os materiais que apresentaram maiores concentrações médias de fluoreto total foram Hydrogum (7052,87μg/g), Jeltrate Plus (6519,68μg/g) e Orthoprint (6218,18μg/g).Apenas os materiais das marcas Hydrogum e Jeltrate apresentaram diferenças nas concentrações de fluoretos entre os lotes um e dois.Os materiais apresentaram diferenças na liberação de fluoretos dos moldes, cujas maiores concentrações médias foram liberadas pelas marcas Hydrogum e Orthoprint.O meio influenciou na liberação de fluoreto, sendo que na saliva foi menor que na água e nesta foi inferior ao ácido.Os moldes dos materiais que mais liberaram fluoretos nos três meios (saliva, água e ácido) foram os do Hydrogum e Orthoprint.Considerando que as concentrações de fluoretos encontradas nos alginatos são altas e que existem diferentes fontes de exposição aos fluoretos, há necessidade de constante monitoramento dos alginatos para uso odontológico

Quantitative analysis of potentially toxic metals in alginates for dental use

Alginate is one de materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closed-system microwave oven. Aqua regia (4 mL concentrated HCl:HNO3, 3:1 v/v) and hydrofluoric acid (2mL concentrated HF) were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so, it is advisable to monitor potentially toxic materials continually and to analyze their plasmatic levels in the professionals working with them

Profile of tuberculosis--an Army experience.

With the advent of HIV infection an increased awareness has arisen on its effect on the incidence of various diseases. In the Indian context an increased incidence of Tuberculosis has been expected. The Army is a controlled relatively healthy constituent of the general population. It hence provides an ideal sample for gauging any dramatic change in incidence. The present paper covers the secular trend of the disease from the days of independence and highlights the differing rates in the stratum of society within the Army. With increased awareness and improvement in diagnostic facilities an increased incidence of the disease has been noticed. However a prospective study to further study various features of the disease as well its correlation if any with HIV is necessary. The paper also touches upon manpower wastage and age profile of Tuberculosis in the Army, which is an important concern to them.

Distrofia "lattice" corneana / Lattice corneal dystrophy

Foram estudados 8 membros de uma mesma família no Departamento de Córnea do Serviço de Oftalmologia do Instituto Benjamim Cosntant (IBC), abrangendo 3 geraçöes, tendo sido encontrado 4 portadores de distrofia "lattice" corneana. A faixa etária variou entre 8 e 58 anos de idade, sendo 3 homens e 1 mulher. Nenhum deles apresentava sinais que pudessem ser correlacionados à amiloidose sistêmica. Dentro da mesma família há relato de mais 10 casos com a mesma patologia corneana.

Knowledge, attitude and beliefs about measles and vaccination coverage in a rural area.

In the present study an attempt was made to collect data on the attitude, belief and customs of mothers regarding occurrence of measles among children in a rural area in Jammu region. Their views on the various aspects of the disease have been highlighted in this article. Simultaneously an effort was also made to evaluate the vaccination coverage of measles vaccine in the study area 2 1/2 years after its introduction into the Universal Immunization Programme (UIP). This study brings out the scope of health education in the eventual goal of eradicating measles in the country.