A bioabsorbable plug implant, suitable for bone tissue regeneration, includes a first portion, and a second portion extending outwardly from the first portion, the first and second portions formed from expandable material. A method for bone tissue regeneration includes providing a bioabsorbable plug implant, wherein the implant has a first portion and a second portion extending outwardly from the first portion. The first and second portions are formed from expandable material. The second portion is inserted into a defect or gap of a bone. The first surface engages the outside contour of the defect or gap. The plug implant is allowed to contact body fluids, thereby expanding the size of the plug implant so that the plug fits into the defect or gap.