A comparative study of two coating methods on titanium (Ti) substrates, sol-gel and electrophoresis processes, was performed. Before coating, two different surface treatments were employed. The hydroxyapatite (HA) powder were characterized by infrared spectroscopy (FTIR) and X-ray diffraction (XRD) while coated samples were examined by using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). Both techniques seem to be suitable to coat Ti. A previous surface treatment on metallic titanium seems to be fundamental to enhance coat uniformity and adhesion that was estimated by the adhesive tape test. The decrease in calcination temperature did not affect the coating adhesion.

O contato de metais, usados como biomateriais, em soluções que simulam a parte inorgânica e acelular do plasma sanguíneo (SBF) permite avaliar sua capacidade de precipitar fosfatos de cálcio. Estes fosfatos podem se formar na interface material-tecido, sendo importantes quando o material é implantado in vivo. Para tanto, várias soluções que possibilitam a deposição biomimética, como as de Kokubo, Neuman e Ringer são usadas na promoção da precipitação de fosfatos. Estas soluções utilizam diversos reagentes, sendo que muitos deles não são necessários na estequiometria dos principais fosfatos de cálcio. A partir de um estudo teórico que prevê a estabilidade termodinâmica de soluções, houve a motivação para projetar e experimentar in vitro uma solução simplificada. Desta forma, amostras de Ti foram lixadas, tratadas com NaOH 1M e posteriormente submetidas à exposição na solução simplificada. Após esta exposição por vários dias as superfícies foram analisadas por MEV/EDS e DRX para avaliar a ocorrência e as características do depósito. Pelos resultados experimentais é possível afirmar que a fase precipitada é o fosfato octacálcico, o que está de acordo com os resultados teóricos.

The contact of materials such as metals used as biomaterials in simulated body solutions (SBF) that mimetize the inorganic and acellular part of blood plasma allows the evaluation of its capacity of calcium phosphate precipitation. These phosphates can precipitate by biomimetic route in the interface material-tissue, being important when the material is in vivo implanted. In addition, there are several solutions that favor this biomimetic deposition such as named as Kokubo, Neuman and Ringer, and they are used in the promotion of precipitation. These solutions employed several reagents; some of them are not necessary in the stoichiometry of the main calcium phosphates. From a theoretical study that showed the possibility of using a simplified solution, we decide to investigate this solution in vitro precipitation conditions. In this way, samples of Ti were grinding, treated with 1M NaOH and subsequently exposed to simplified SBF. After the exposure of surfaces, they were analyzed by SEM/EDS and XRD to characterize the deposits. The experimental results show that the precipitated phase is octacalcium phosphate, which corroborate theoretical findings.