This work presents preliminary results of powder glasses with bactericide effect obtained by ionic exchange between sodium ions, present in glass composition, and silver ions, present in the ionic exchange medium. The powder glass was submitted to ionic exchange in ionic medium containing different concentration of silver species. The results showed a bactericide effect dependence on AgNO3 concentration in the ionic medium. Agar Diffusion Test on Escherichia coli bacteria, EDS analyses was applied to the samples; the results showed there is a critical concentration of silver ions incorporated in the powder glass and a limit to bactericide effect. The tests and analyses reveled that 6 wt% of AgNO3 in ionic medium was the critical concentration.