Final answer:
During the second surgery of an osseointegrated implant, the endosteal implant fixture is exposed and the abutment screw is connected to the anchor and prosthesis.
Step-by-step explanation:
During the second surgery of an osseointegrated implant, several things occur. First, the endosteal implant fixture is exposed, which involves making an incision in the gum tissue and uncovering the implant. Then, the abutment screw is connected to the anchor, which is the part of the implant embedded in the jawbone. Finally, the abutment screw is connected to the prosthesis, such as a crown or denture, which is the visible part of the implant that replaces the missing tooth.