A 43-year-old patient complains of mobility and significant neck exposure of the lower front teeth. Objectively: the gums in the region of the 44, 43, 42, 41, 31, 32, 33, 34 teeth are pale and cyanotic, non-bleeding. The 42, 41, 31, 32 teeth exhibit the I-II grade mobility. The overcrowding of the 42, 41, 31, 32 teeth is present. The necks of the 42, 41, 31, 32 teeth are exposed by 1/2 of the root length, the necks of the 43,33 teeth are exposed by 1/4. What kind of dental prosthesis should be applied in this case?