The invention relates to a process of retraction of sulcus (3), comprising the steps of: (i.) applying a silicone material (4) onto and/or at the vicinity of the boundary of a tooth (1) and adjacent sulcus (3), which silicone material (4) expands during or after its curing reaction； (ii.) applying a cap (6) onto said tooth (1), thereby forming a chamber over said silicone material (4), wherein said chamber comprises as its walls the tooth (1), the cap (6) and an outer section (3a) of said sulcus (3)； whereby said chamber allows for the silicone material (4) to expand into the crevice between sulcus (3) and tooth (1). Said cap (6) is at least partially filled with a plastically deformable material (7) when applied onto said tooth (1) in step (ii.)； and/or said cap (6) is deformable, especially under biting pressure.
