A medical device intended for contact with living tissue comprises a substrate having a surface, which surface comprises a layer comprising one or more compound(s)of at least one non-toxic post-transition metal, such as a gallium or bismuth compound.A layer comprising a compound of at least one non-toxic post-transition metal has been shown to inhibit biofilm formation on the surface of the medical device, which may reduce the risk for infection e.g. around a dental implant. A method of producing the medical device comprises: a) providing a substrate having a surface; and applying a compound of at least one non-toxic post-transition metal onto said surface to form a layer, e.g. using a thin film deposition technique.