The present invention relates to an extra-coronary dental device (1) comprising a one-piece body (2) made of a polymer or co-polymer, obtained by polymerizing a composition comprising a polymerizable monomer based on acrylate, said dental device (1) comprising a surface porosity, over a thickness between 0.1 and 0.8 mm, said porosity comprising pores, the size of which is between 10 μm and 800 μm, over said thickness. The present invention also relates to a method of producing such a device.