RESUMO
The purpose was to evaluate the cytotoxicity of two novel formulations (alpha and beta) of calcium phosphate cements. Positive control, represented by a commercial hydroxyapatite cement, and negative control were included for comparative purposes. A continuous lineage of fibroblastic cells was used, and the effect of the tested materials on both cell proliferation and viability was assessed by counting cell number on hemocytometer and by the trypan blue exclusion test, respectively. Study design attempted to simulate clinical use by allowing direct and indirect contact of cells and cements. Results were analyzed by the Kruskal-Wallis test and indicated that the beta formulation was extremely cytotoxic (P < 0.001), because this material induced the greatest reduction on cell proliferation and viability. The alpha formulation behaved similarly to the positive control regarding its effect on cell proliferation and viability. Thus, it is concluded that alpha formulation has promise for further evaluation of its behavior in vivo.
Assuntos
Fosfatos de Cálcio/toxicidade , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cimentos Dentários/toxicidade , Testes de Toxicidade/métodos , Células Cultivadas , Fibroblastos , HumanosRESUMO
A hidroxiapatia (HA) é o constituinte mineral do osso natural. Por isso nos últimos anos tem havido grande interesse em se sintetizar essa fase para ser usada como biomaterial. Entretanto há grande número de outros compostos de fosfato de cálcio que poderão ser formados juntamente com a HA dependendo das condições de precipitação. Estudou-se os efeitos das condições de precipitaçãona obtenção de HA, temperatura e razão Ca/P sobre as característica físico-químicas do precipitado após a calcinação à 800 C. A fase cristalina obtida para as razões Ca/P iguais a 1,67 2,0 foi HA e para amostras ecom razão Ca/P=1,0 foi obtido o difosfato de cálcio (DCP) e o ß-fosfato tricálcico (ß-TCP)
Abstract Hydroxyapatite (HA) is the mineral constituent of natural bone. Because of this, in the last years, there has been a considerable effort towards chemically producing it to be used as a biomaterial. However, there are a large number of calcium phosphate compounds that can be produce together with the HA, depending on the precipitation conditions. ln this work the effects of the precipitation conditions, temperature and Ca/P ratio, on the physico-chemical characteristics of the precipitated powder, after it has been calcined at 800ºC. was studied. For the Ca/P ratios of 1,67 and 2,0 HA was the only mineral phase present and for the Ca/P ratio of LO the phase calcium orthophosphate and P-TCP were also observed