A medical device intended for contact with living tissue comprises a substrate having a surface, which surface comprises a layer comprising gallium oxide. A layer comprising a gallium oxide 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 gallium compound onto said surface to form a layer, preferably using a thin film deposition technique.