The invention relates to a system for determining the quality of a bone structure, comprising: a body adapted for drilling through the bone structure; a first electrode arranged on the body so as to come into contact with the bone structure during drilling; a second electrode arranged on the body so as to come into contact with the bone structure at a distance from the first electrode during drilling; an electric generator adapted to apply an electric current between the first and second electrodes for a pre-determined period of time; a measuring device adapted (i) to measure the electric current, continuously and over the pre-determined period, an electrical magnitude representative of the aptitude of the bone structure for allowing electric current to pass therethrough and (ii) to deliver, continuously and over the pre-determined period, a signal representative of the quality of the bone structure between the contact surfaces of the first and second electrodes, using the determined electrical magnitude.