A root implant includes a body portion (11), a drilling portion (12) formed thereon, a positioning hole (13) formed opposite to the drilling portion, and a thread portion (14) spiraled on the body portion. The body portion and the coarse thread have respective first openings (111) and second openings (1411) which are processed by a high-energy optothermal method to be spaced apart by equal distances. The first openings and second openings accommodate accretions grown from the alveolar bone when the root implant interfaces with the alveolar bone. The body portion and the coarse thread includes first joint sections and second joint sections formed between any two of the first openings and the second openings respectively to allow the accretions to clamber and link together, thereby providing a tight combination between the root implant and the alveolar bone, preventing the loosening problem caused by an external force and promoting a positioning effect of the root implant.
