The clinical and prosthetic use of the o-ball for fixed/removable denture retention has been used by dentists worldwide for the past thirty-five years. With the development of the metal encapsulator to house the o-ring, clinicians have reported possibilities of locking the overdenture onto the o-ring abutment if space existed between the inserted encapsulator and the underlying gingiva.
OCO Biomedical has been offering the o-ball prosthetic kit with a large red-colored o-ring that is called the “block-out” ring. It is used to prevent any acrylic from locking onto the abutment during direct or indirect processing.
So Doctors once you place the loaded metal encapsulator with the o-ring onto the abutment, make sure to check the space between the encapsulator and the underlying gingiva. If there is space, remove the encapsulator and place the red block out o-ring onto the abutment and then firmly replace the metal encapsulator. You are now ready for the processing procedure. Remember to remove the red block out ring after the processing.